Intercropping is used widely by smallholder farmers in developing countries to increase land productivity and profitability. We conducted a maize/peanut intercropping experiment in the 2015 and 2016 growing seasons in...Intercropping is used widely by smallholder farmers in developing countries to increase land productivity and profitability. We conducted a maize/peanut intercropping experiment in the 2015 and 2016 growing seasons in Shandong, China. Treatments included sole maize (SM), sole peanut (SP), and an intercrop consisting of four rows of maize and six rows of peanut (IM and IP). The results showed that the intercropping system had yield advantages based on the land equivalent ratio (LER) values of 1.15 and 1.16 in the two years, respectively. Averaged over the two years, the yield of maize in the intercropping was increased by 61.05% compared to that in SM, while the pod yield of peanut was decreased by 31.80% compared to SP. Maize was the superior competitor when intercropped with peanut, and its productivity dominated the yield of the intercropping system in our study. The increased yield was due to a higher kernel number per ear (KNE). Intercropping increased the light transmission ratio (LTR) of the ear layer in the maize canopy, the active photosynthetic duration (APD), and the harvest index (HI) compared to SM. In addition, intercropping promoted the ratio of dry matter accumulation after silking and the distribution of 13C-photosynthates to grain compared to SM. In conclusion, maize/peanut intercropping demonstrated the potential to improve the light condition of maize, achieving enhanced photosynthetic characteristics that improved female spike differentiation, reduced barrenness, and increased KNE. Moreover, dry matter accumulation and 13C-photosynthates distribution to grain of intercropped maize were improved, and a higher grain yield was ultimately obtained.展开更多
Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant h...Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant hybrids breeding.In this study,a major QTL,Resistance to Pythium stalk rot 1(RPSR1),was identified from a set of recombinant inbred lines derived from MS71 and POP.Using a recombinant progeny testing strategy,RPSR1 was fine-mapped in a 472 kb interval.Through candidate gene expression,gene knock-down and knock-out studies,a leucine-rich repeat receptor-like kinase gene,PEP RECEPTOR 2(ZmPEPR2),was assigned as a PSR resistance gene.These results provide insights into the genetic architecture of resistance to PSR in maize,which should facilitate breeding maize for resistance to stalk rot.展开更多
Agricultural practices significantly contribute to greenhouse gas(GHG)emissions,necessitating cleaner production technologies to reduce environmental pressure and achieve sustainable maize production.Plastic film mulc...Agricultural practices significantly contribute to greenhouse gas(GHG)emissions,necessitating cleaner production technologies to reduce environmental pressure and achieve sustainable maize production.Plastic film mulching is commonly used in the Loess Plateau region.Incorporating slow-release fertilizers as a replacement for urea within this practice can reduce nitrogen losses and enhance crop productivity.Combining these techniques represents a novel agricultural approach in semi-arid areas.However,the impact of this integration on soil carbon storage(SOCS),carbon footprint(CF),and economic benefits has received limited research attention.Therefore,we conducted an eight-year study(2015-2022)in the semi-arid northwestern region to quantify the effects of four treatments[urea supplied without plastic film mulching(CK-U),slow-release fertilizer supplied without plastic film mulching(CK-S),urea supplied with plastic film mulching(PM-U),and slow-release fertilizer supplied with plastic film mulching(PM-S)]on soil fertility,economic and environmental benefits.The results revealed that nitrogen fertilizer was the primary contributor to total GHG emissions(≥71.97%).Compared to other treatments,PM-S increased average grain yield by 12.01%-37.89%,water use efficiency by 9.19%-23.33%,nitrogen accumulation by 27.07%-66.19%,and net return by 6.21%-29.57%.Furthermore,PM-S decreased CF by 12.87%-44.31%and CF per net return by 14.25%-41.16%.After eight years,PM-S increased SOCS(0-40 cm)by 2.46%,while PM-U decreased it by 7.09%.These findings highlight the positive effects of PM-S on surface soil fertility,economic gains,and environmental benefits in spring maize production on the Loess Plateau,underscoring its potential for widespread adoption and application.展开更多
A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,...A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.展开更多
Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restric...Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.展开更多
The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use e...The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use efficiency and enhancing crop stress resistance.Nevertheless,the precise interaction between soil warming(SW)and SN remains unclear.In order to ascertain the impact of SW on maize growth and whether SN can improve the tolerance of maize to SW,a two-year field experiment was conducted(2022-2023).The aim was to examine the influence of two SW ranges(MT,warming 1.40℃;HT,warming 2.75℃)and two nitrogen application methods(N1,one-time basal application of nitrogen fertilizer;N2,one third of base nitrogen fertilizer+two thirds of jointing stage supplemental nitrogen fertilizer)on maize root growth,photosynthetic characteristics,nitrogen use efficiency,and yield.The results demonstrated that SW impeded root growth and precipitated the premature aging of maize leaves following anthesis,particularly in the HT,which led to a notable reduction in maize yield.In comparison to N1,SN has been shown to increase root length density by 8.54%,root bleeding rate by 8.57%,and enhance root distribution ratio in the middle soil layers(20-60 cm).The interaction between SW and SN had a notable impact on maize growth and yield.The SN improved the absorption and utilization efficiency of nitrogen by promoting root development and downward canopy growth,thus improving the tolerance of maize to SW at the later stage of growth.In particular,the N2HT resulted in a 14.51%increase in the photosynthetic rate,a 18.58%increase in nitrogen absorption efficiency,and a 18.32%increase in maize yield compared with N1HT.It can be posited that the SN represents a viable nitrogen management measure with the potential to enhance maize tolerance to soil high-temperature stress.展开更多
Maize value-added products play a crucial role in reducing post-harvest losses, enhancing food security, and generating income. While extensive research has focused on maize production in Cameroon, the exploration of ...Maize value-added products play a crucial role in reducing post-harvest losses, enhancing food security, and generating income. While extensive research has focused on maize production in Cameroon, the exploration of its value-added products and their profitability in the North-West Region remains underexplored. This study examined the profitability of maize value-added products in Mezam Division, with the objectives to: 1) identify various maize-based products, 2) assess the diversity of these products, 3) conduct a cost-benefit analysis of selected products, 4) examine the relationship between profitability and product diversity, and 5) identify key constraints impacting profitability. To achieve these objectives, structured questionnaires were administered to 500 small-scale maize entrepreneurs randomly selected from five subdivisions. Descriptive statistics were used to analyze objective 1 and 5, while the Shannon Diversity Index was employed to assess product diversity. Additionally, a cost-benefit analysis was conducted on four selected products namely pap, parched corn, peeled parboiled corn, and corn beer, and a correlation analysis was used to examine objective 4. In total, 13 maize value-added products were identified, with a diversity index of 4.4. The total cost of processing the four selected products per entrepreneur using 18 kg of maize per product was FCFA 83631.5 (US $132.75), while the total revenue was FCFA 121864.5 (US $193.43), resulting in an economic profit of FCFA 38,233 (US $60.69). Pap emerged as the most profitable product, with an economic profit of FCFA 27,875 (US $44.24), while corn beer was the least profitable, with an economic profit of FCFA 2133.46 (US $3.39). The correlation analysis revealed a strong negative relationship between product diversity and profitability (r = −0.91), indicating that entrepreneurs can maximize profitability by focusing on a few high-demand products like pap and parched corn. Key constraints to profitability included fluctuating market prices, high production costs, limited access to finance, and inadequate storage facilities. Despite these challenges, our findings indicate that maize value addition is profitable in Mezam Division. Entrepreneurs can leverage this data for informed decision-making and future investments. It is recommended that the government promote maize value addition and provide financial support for modern processing equipment to boost profitability and income generation.展开更多
Pentatricopeptide repeat(PPR)proteins are a large group of eukaryote-specific RNA-binding proteins that play pivotal roles in plant organelle gene expression.Here,we report the function of PPR21 in mitochondrial intro...Pentatricopeptide repeat(PPR)proteins are a large group of eukaryote-specific RNA-binding proteins that play pivotal roles in plant organelle gene expression.Here,we report the function of PPR21 in mitochondrial intron splicing and its role in maize kernel development.PPR21 is a typical P-type PPR protein targeted to mitochondria.The ppr21 mutants are arrested in embryogenesis and endosperm development,leading to embryo lethality.Null mutations of PPR21 reduce the splicing efficiency of nad2 intron 1,2,and 4 and impair the assembly and activity of mitochondrial complex I.Previous studies show that the P-type PPR protein EMP12 is required for the splicing of identical introns.However,our protein interaction analyses reveal that PPR21 does not interact with EMP12.Instead,both PPR21 and EMP12 interact with the small MutS-related(SMR)domain-containing PPR protein 1(PPR-SMR1)and the short P-type PPR protein 2(SPR2).PPR-SMR1 interacts with SPR2,and both proteins are required for the splicing of many introns in mitochondria,including nad2 intron 1,2,and 4.These results suggest that a PPR21-(PPR-SMR1/SPR2)-EMP12 complex is involved in the splicing of nad2 introns in maize mitochondria.展开更多
Maize is an important source of calories and protein in human lives in many countries of the world and is the main staple food in Africa, particularly in eastern Africa. In the Sudan, the low yield of maize was mainly...Maize is an important source of calories and protein in human lives in many countries of the world and is the main staple food in Africa, particularly in eastern Africa. In the Sudan, the low yield of maize was mainly due to the use of low yielding landraces. It is necessary to carry out breeding programs that deal with the production of high yielding, adaptable new varieties. Therefore, this study aimed to estimate genetic variability, heritability, genotypic performance and interrelationships among the traits. Ten maize genotypes evaluated at White Nile Research Station Farm, Kosti, of the Agricultural Research Corporation (ARC), Wad Medani Sudan were planted in a randomized complete block design with three replications during the two seasons of 2021 and 2022. Most evaluated genotypes exhibited a wide and significant variation in the 11 measured traits. Genotypic coefficient of variation and genetic advance were recorded for days to 50% tasseling, ear diameter (cm), number of grains per row and grain yield (t/ha) in both seasons. High heritability and genetic advance were recorded for grain yield, ear length, ear height, plant height, number of rows per ear, ear weight, days to 50% tasseling, 100-grain weight and days to 50% silking. Moreover, there was a highly significant and positive correlation of grain yield with number of rows per ear (r = 0.479), ear length (r = 0.381), 100-grain weight (r = 0.344) and days to 50% tasseling (r = 0.214). The highest yielding five genotypes across the seasons were TZCOM1/ZDPSYN (4.2 t/ha), EEPVAH-3 (4.2 t/ha), F2TWLY131228 (4.1 t/ha), PVA SYN6F2 (3.9 t/ha) and EEPVAH-9 (3.8 t/ha) these were needed to check the adaptability, stability and to test major maize growing areas to make sound recommendations for release.展开更多
Twenty short-statured maize inbred lines were collected from CIMMYT India and Mexico through the Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Gazipur. The experiment was conducted from N...Twenty short-statured maize inbred lines were collected from CIMMYT India and Mexico through the Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Gazipur. The experiment was conducted from November 2020 to April 2021 in three different agroecological regions such as BARI, Gazipur, RARS Barisal and RARS Rangpur. Seven inbred lines were selected on the basis of genetic diversity and per se performance and they were crossed separately in a 7 × 7 half diallel fashion, producing 21F1 hybrids in 2019 which were evaluated at three locations. However, variances due to GCA were much higher in magnitude than SCA for all the characters indicating preponderance of additive gene effects on the inheritance of these characters. Two parents viz., P3 (CML33) and P4 (CML41) were good general combiners and two crosses viz., P4 × P5 (CML41 × CML31) and P5 × P7 (CML31 × CML124) expressed significant positive SCA effects coupled with significant positive heterosis for grain yield and for most of the yield contributing characters over the two commercial check varieties BHM 9 and NK40. Four crosses: P1 × P5 (CML116 × CML31), P1 × P6 (CML116 × CML32), P2 × P6 (CML72 × CML32) and P3 × P4 (CML33 × CML41), exhibited significant and negative SCA effects for both plant and ear height which were desirable for short stature. Genotypes x location interaction was also significant for maximum characters, suggesting that genotypes interacted significantly in different environments.展开更多
Smallholder farming in West Africa faces various challenges, such as limited access to seeds, fertilizers, modern mechanization, and agricultural climate services. Crop productivity obtained under these conditions var...Smallholder farming in West Africa faces various challenges, such as limited access to seeds, fertilizers, modern mechanization, and agricultural climate services. Crop productivity obtained under these conditions varies significantly from one farmer to another, making it challenging to accurately estimate crop production through crop models. This limitation has implications for the reliability of using crop models as agricultural decision-making support tools. To support decision making in agriculture, an approach combining a genetic algorithm (GA) with the crop model AquaCrop is proposed for a location-specific calibration of maize cropping. In this approach, AquaCrop is used to simulate maize crop yield while the GA is used to derive optimal parameters set at grid cell resolution from various combinations of cultivar parameters and crop management in the process of crop and management options calibration. Statistics on pairwise simulated and observed yields indicate that the coefficient of determination varies from 0.20 to 0.65, with a yield deviation ranging from 8% to 36% across Burkina Faso (BF). An analysis of the optimal parameter sets shows that regardless of the climatic zone, a base temperature of 10˚C and an upper temperature of 32˚C is observed in at least 50% of grid cells. The growing season length and the harvest index vary significantly across BF, with the highest values found in the Soudanian zone and the lowest values in the Sahelian zone. Regarding management strategies, the fertility mean rate is approximately 35%, 39%, and 49% for the Sahelian, Soudano-sahelian, and Soudanian zones, respectively. The mean weed cover is around 36%, with the Sahelian and Soudano-sahelian zones showing the highest variability. The proposed approach can be an alternative to the conventional one-size-fits-all approach commonly used for regional crop modeling. Moreover, it has the potential to explore the performance of cropping strategies to adapt to changing climate conditions.展开更多
Increasing concern over the amount of insecticide residues in food has encouraged research for ecologically sound strategies to effectively manage stored-product insect pests and protect living organisms and the envir...Increasing concern over the amount of insecticide residues in food has encouraged research for ecologically sound strategies to effectively manage stored-product insect pests and protect living organisms and the environment. Botanicals were evaluated as potential alternatives to control maize weevil, Sitophilus zeamais Motschulsky, in stored sorghum, Sorghum bicolor (L.) Moench. Beetles and moths of stored grain at farm and consumer levels damage 5 - 35% worldwide and >40% in tropical countries. Maize weevil is the most damaging storage insect of sorghum grain. Management of storage insects relies on insecticides that leave residues in food and the environment. Treatments were powders of neem bark, Azadirachta indica;mesquite pods, Prosopis glandulosa;milkweed leaves, Asclepias speciosa;and a check (no botanical powder). Eight newly emerged maize weevils were provided 5 g of Malisor-84 grain treated with three doses of each plant powder. Every 2 days, data were recorded on the number of adults killed by each treatment. Percentage killed was calculated by dose per treatment and compared with the check. Grain loss was calculated based on initial and final weights. LD50 was determined by probit analysis, and associations between variables were assessed by simple linear correlation. Powder of mesquite and milkweed at 0.2 g were more effective than neem or the check in killing S. zeamais (>90%) and reducing grain damage (34 - 35.2%) and weight loss (0.8%). Milkweed at 0.1 g and neem at 0.2 g killed 78.1% of weevils. Neem at 0.05 g was slow acting, resulting in 62.5% dead and more grain damage (59.5%) and weight loss (3.6%). Botanicals at low doses (LD50 = 0.2 - 0.4 g) showed efficacy in controlling maize weevils and are recommended alternatives to guarantee quantity and quality of stored cereal grains.展开更多
Maize (Zea mays L.) is the world’s leading cereal crop, with production estimated at over 1 billion tonnes in 2022. In Côte d’Ivoire, maize is one of the most widely consumed foods, with national production exc...Maize (Zea mays L.) is the world’s leading cereal crop, with production estimated at over 1 billion tonnes in 2022. In Côte d’Ivoire, maize is one of the most widely consumed foods, with national production exceeding 1 million tonnes in 2022. Despite its importance, this crop is subject to numerous biotic constraints, including Maize streak virus (MSV). The objective of this study was to characterize MSV isolates from Côte d’Ivoire using molecular biology techniques. To achieve this, maize leaf samples displaying characteristic symptoms of MSV were collected from different agro-ecological zones (AEZs) of Côte d’Ivoire. Total DNA was extracted from the collected samples using the CTAB method and quantified with a Nanodrop spectrophotometer. The C2 region of the MSV genome’s open reading frame (ORF) was amplified through polymerase chain reaction (PCR) using MSV-specific primers. The resulting PCR products were sequenced using the Sanger method. Bioinformatics analysis was performed using MSV sequences from other African countries (retrieved from NCBI) alongside sequences obtained in this study. The analysis was conducted using MEGA X version 10.05 software. The results showed that the main symptoms observed in the field included the presence of longitudinal light green streaks on leaves, stunted plant growth, and incomplete seed development in infected plants. Phylogenetic analysis of the sequences from Côte d’Ivoire revealed three monophyletic groups, with sequences of some isolates collected from the same plot belonging to different groups. The MSV sequences from Côte d’Ivoire are very close to those from Rwanda. This study underscores the need for further investigation into the genetic diversity of MSV strains to enhance the diagnosis and management of this viral disease, which is particularly prevalent in maize crops in Côte d’Ivoire.展开更多
In this study,eight different varieties of maize seeds were used as the research objects.Conduct 81 types of combined preprocessing on the original spectra.Through comparison,Savitzky-Golay(SG)-multivariate scattering...In this study,eight different varieties of maize seeds were used as the research objects.Conduct 81 types of combined preprocessing on the original spectra.Through comparison,Savitzky-Golay(SG)-multivariate scattering correction(MSC)-maximum-minimum normalization(MN)was identified as the optimal preprocessing technique.The competitive adaptive reweighted sampling(CARS),successive projections algorithm(SPA),and their combined methods were employed to extract feature wavelengths.Classification models based on back propagation(BP),support vector machine(SVM),random forest(RF),and partial least squares(PLS)were established using full-band data and feature wavelengths.Among all models,the(CARS-SPA)-BP model achieved the highest accuracy rate of 98.44%.This study offers novel insights and methodologies for the rapid and accurate identification of corn seeds as well as other crop seeds.展开更多
Maize/soybean intercropping systems are commonly used in developing countries,but few studies have been performed to elucidate the differences in nutrient efficiency and rhizosphere microbiome,especially when maize is...Maize/soybean intercropping systems are commonly used in developing countries,but few studies have been performed to elucidate the differences in nutrient efficiency and rhizosphere microbiome,especially when maize is intercropped with different soybean varieties.In this study,field experiments were conducted to compare the growth and yield of two soybean(Glycine max)varieties,BD2 and YC03-3,and one maize(Zea mays)variety,Huazhen,in mono-cropped and intercropped cultures.The plant biomass and N content of both crops in BD2/maize intercropping were significantly improved compared to their monoculture,but no such effects were observed in the plants of YC03-3/maize intercropping.The yield of BD2 intercropped with maize exhibited a 37.5%increment above that of BD2 in monoculture.Moreover,19.2-29.1%longer root length of maize and 19.0-39.4%larger root volume of BD2 were observed in BD2/maize intercropping than in monoculture,but no growth advantage was observed in YC03-3/maize intercropping.Maize showed root avoidance when intercropped with BD2,but space competition when intercropped with YC03-3.16S rRNA amplicon sequencing showed that compared with the monoculture system,rhizobacteria community composition in BD2/maize intercropping changed more significantly than that of the YC03-3/maize intercropping system.In BD2/maize intercropping,most of the rhizobacteria community biomarker bacteria of BD2 were positively correlated with plant biomass,as well as plant P and N content.Maize tended to recruit Rhizobiales and Proteobacteria,which showed positive correlation with plant biomass and N content,respectively,as well as soil available N.In conclusion,soybean varieties determined the advantages of maize/soybean intercropping through root-root interactions and modification of rhizobacteria communities.Our insight emphasizes a linkage between root traits and the rhizobacteria community,which shows the importance of optimizing intercropping systems by selection of appropriate crop varieties.展开更多
Maize(Zea mays L.),a globally significant cereal crop,is produced in vast quantities worldwide.However,its growth is severely constrained by low temperatures,particularly during seed germination,which significantly im...Maize(Zea mays L.),a globally significant cereal crop,is produced in vast quantities worldwide.However,its growth is severely constrained by low temperatures,particularly during seed germination,which significantly impairs seedling emergence.In this study,genetic diversity across six germination-associated phenotypic traits(RGR,RSL,RTL,RRSA,RRV,and RSVI)of 304 inbred lines was analyzed,to evaluate the capacity of these lines for low-temperature tolerance.Genome-wide association study(GWAS)was carried out by combining six germination-associated phenotypic traits and genotypic data from 30-fold resequencing.The gene ZmBARK1 was identified through integrated GWAS and RNA-seq analyses,and its association with low-temperature tolerance during maize germination was validated by quantitative real-time PCR(qRT-PCR).ZmBARK1,encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1,was located on the bin 4.09 region of maize chromosome 4.Amino acid comparison and subcellular localization analyses revealed that ZmBARK1 is highly homologous to AtBAK1 and is localized to the plasma membrane of the cell,which may be involved in regulating brassinosteroid(BR)signaling.In addition,we revealed the role of ZmBARK1 in low-temperature tolerance during maize germination.Compared with wild-type(WT),the ethyl methanesulfonate(EMS)mutant zmbark1 was characterized by substantially enhanced low-temperature tolerance.Overall,these findings provide promising candidate genes,improve low-temperature tolerance in maize,and advance the understanding of regulatory mechanisms underlying maize's response to low-temperature stress.展开更多
The environment has an important impact on maize(Zea mays L.)production,making it necessary to identify plant adaptation regions that are suitable for different maize varieties.Traditional methods using field trials a...The environment has an important impact on maize(Zea mays L.)production,making it necessary to identify plant adaptation regions that are suitable for different maize varieties.Traditional methods using field trials are costly and restricted to a limited number of areas.Identifying adaptation regions based on climate data has great potential,but a basic understanding and a prediction approach for diverse maize varieties are lacking.Here,we collected a representative dataset comprising 32,840 data points from the National Maize Variety Trial Data Management Platform.We employed three traits to characterize the adaptability of different maize varieties:PH(plant height),DTS(days to silking),and yield.First,we quantified the contributions of variety(V),environment(E),and V×E to variance in the three adaptationrelated traits.The mean contributions of E to variance in PH,DTS,and yield were 54.50%,82.87%,and 75.92%,respectively,suggesting that environmental effects are crucial for phenotype construction.Second,we analyzed correlations between the three traits and three environmental indices:GDD(growing degree days),PRE(precipitation),and SSD(sunshine duration).The highest absolute correlation coefficients between phenotypes and environmental indices were 0.15–0.69 at the whole-data level.To predict variety adaptation on a national scale,we modeled the three traits using environmental indices and best linear unbiased predictors(BLUPs)via the random forest algorithm.The predictive abilities of our models for PH,DTS,and yield were 0.90(MAE=9.95 cm),0.99(MAE=1.09 d),and 0.95(MAE=0.55 t ha^(−1)),respectively,indicating that our proposed framework can predict adaptationrelated traits for diverse maize varieties in China.展开更多
Crude fat is an important nutritional component of maize kernels.However,the genetic mechanisms underlying crude fat content in maize kernels remain elusive.Previous studies used single-model genome-wide association s...Crude fat is an important nutritional component of maize kernels.However,the genetic mechanisms underlying crude fat content in maize kernels remain elusive.Previous studies used single-model genome-wide association studies(GWAS)with limited population sizes,which can result in false loci positives and hinder functional gene identification.Therefore,this study used a population consisting of 495 maize inbred lines,combined with 1.25 million single nucleotide polymorphisms(SNPs),and implemented GWAS using six models to identify quantitative trait nucleotides(QTNs)controlling crude fat content and to mine key genes.The results revealed a wide variation in crude fat content(0.62-16.03%)and broad-sense heritability(H^(2))(96.23%).In total,744 significant QTNs were detected,with 147 co-located across different models,environments,and methods.Based on the 147 colocated QTNs,candidate genes were searched at 50 kb up-and down-stream intervals of each QTN.We finally screened eight candidate genes(GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,GRMZM2G368838,GRMZM2G058496,GRMZM2G090669,GRMZM2G001241,and GRMZM2G333454)related to crude fat content that exhibited high expression levels during kernel development in maize inbred line B73.Notably,GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,and GRMZM2G368838 are involved in the linoleic acid metabolic pathway,oil metabolism,kernel growth,and development in maize.Furthermore,co-expression network analysis revealed that the eight candidate genes strongly correlated with 30 known genes.Proteins encoded by candidate genes interact with other proteins and play an important role in oil content and oleic acid metabolism in maize kernels.The best haplotypes of candidate genes might increase crude fat content without decreasing maize yield.These results broaden the understanding of the genetic mechanism of crude fat content and facilitate marker-assisted selection for high-crude fat breeding programs for maize.展开更多
Meiosis,a critical process for sexual reproduction,requires precise regulation to ensure the correct progression of meiotic stages.In yeast and animals,errors in meiotic recombination and homologous chromosomes synaps...Meiosis,a critical process for sexual reproduction,requires precise regulation to ensure the correct progression of meiotic stages.In yeast and animals,errors in meiotic recombination and homologous chromosomes synapsis bring a surveillance mechanism named pachytene checkpoint to prevent pachytene exit.However,most plant mutants with defects in meiotic prophase I continue cell cycle progression,which hindered the characterization of factors controlling the prophase I to metaphase I transition.Here,we characterized a male-sterile mutant in maize,prolonged prophase1(pp1),which exhibited pachytene and diakinesis arrest in male meiosis,and abnormal chromatin condensation.Using mapbased cloning,the PP1 gene was isolated as a PHD family transcription factor,and its transcripts of PP1 were preferentially accumulated in tapetum and male germline cells during microsporogenesis.Transcriptomic analysis of the pp1 mutant revealed downregulation of genes associated with chromatin assembly,cell cycle,and male meiosis,correlating with observed meiotic arrest and chromatin condensation defects.These findings highlight the role of PP1 in maize microsporogenesis,and providing more insights into the mechanisms regulating the meiotic progression in maize.展开更多
One-third of the global population is affected by micronutrient deficiency, particularly folate. Although folate synthesis has been relatively well characterized, few folate-related genes in maize have been cloned, an...One-third of the global population is affected by micronutrient deficiency, particularly folate. Although folate synthesis has been relatively well characterized, few folate-related genes in maize have been cloned, and the molecular mechanism regulating folate synthesis in maize remains unclear. In this study,transcriptome and proteome analyses of three waxy maize inbred lines with high, medium, and low folate contents were performed to identify key genes controlling folate biosynthesis. Pairwise comparisons revealed 21 differentially expressed genes and 20 differentially expressed proteins potentially associated with folate biosynthesis in the three lines. Six key folate-associated genes, Zm Mocos2, Zm GGH,Zm ADCL2, Zm CBR1, Zm SHMT, and Zm Pur H, were identified. These genes encode enzymes that potentially function in folate biosynthesis. Functional validation of one of these genes, Zm ADCL2, using an EMS mutant(Mut9264) showed that a 4-base insertion in an exon increased the folate content of fresh maize kernels 1.37-fold that of the wild type. Zm ADCL2 was considered a potential target for generating maize lines with higher folate content. KEGG enrichment analysis of differentially expressed genes and proteins showed that several pathways in addition to folate biosynthesis were likely indirectly involved in folate metabolism and content(e.g., glycine, serine, and threonine metabolism;purine metabolism;cysteine and methionine metabolism;alanine, aspartate and glutamate metabolism;glutathione metabolism;and pyruvate metabolism. The transcriptome and proteomic data generated in this study will help to clarify the mechanisms underlying folate accumulation and aid breeding efforts to biofortify maize with folate.展开更多
基金support of the National Key Research and Development Program of China (2017YFD0301001)the National Natural Science Foundation of China (31301274 and 31171497)+1 种基金funds from the Shandong “Double Tops” Program, China (SYL2017XTTD14)the Open Project of State Key Laboratory of Crop Biology in Shandong Agricultural University, China (2018KF10)
文摘Intercropping is used widely by smallholder farmers in developing countries to increase land productivity and profitability. We conducted a maize/peanut intercropping experiment in the 2015 and 2016 growing seasons in Shandong, China. Treatments included sole maize (SM), sole peanut (SP), and an intercrop consisting of four rows of maize and six rows of peanut (IM and IP). The results showed that the intercropping system had yield advantages based on the land equivalent ratio (LER) values of 1.15 and 1.16 in the two years, respectively. Averaged over the two years, the yield of maize in the intercropping was increased by 61.05% compared to that in SM, while the pod yield of peanut was decreased by 31.80% compared to SP. Maize was the superior competitor when intercropped with peanut, and its productivity dominated the yield of the intercropping system in our study. The increased yield was due to a higher kernel number per ear (KNE). Intercropping increased the light transmission ratio (LTR) of the ear layer in the maize canopy, the active photosynthetic duration (APD), and the harvest index (HI) compared to SM. In addition, intercropping promoted the ratio of dry matter accumulation after silking and the distribution of 13C-photosynthates to grain compared to SM. In conclusion, maize/peanut intercropping demonstrated the potential to improve the light condition of maize, achieving enhanced photosynthetic characteristics that improved female spike differentiation, reduced barrenness, and increased KNE. Moreover, dry matter accumulation and 13C-photosynthates distribution to grain of intercropped maize were improved, and a higher grain yield was ultimately obtained.
基金supported by National Natural Science Foundation of China(32302371 to Junbin Chen)the National Key Research and Development Program,Ministry of Science and Technology of China(2022YFD1201802 to Wangsheng Zhu)Research Program from State Key Laboratory of Maize Biobreeding(SKLMB2424 to Wangsheng Zhu).
文摘Pythium stalk rot(PSR)is a destructive disease of maize,severely affecting yield and grain quality.The identification of quantitative trait loci(QTL)or genes for resistance to PSR forms the basis of diseaseresistant hybrids breeding.In this study,a major QTL,Resistance to Pythium stalk rot 1(RPSR1),was identified from a set of recombinant inbred lines derived from MS71 and POP.Using a recombinant progeny testing strategy,RPSR1 was fine-mapped in a 472 kb interval.Through candidate gene expression,gene knock-down and knock-out studies,a leucine-rich repeat receptor-like kinase gene,PEP RECEPTOR 2(ZmPEPR2),was assigned as a PSR resistance gene.These results provide insights into the genetic architecture of resistance to PSR in maize,which should facilitate breeding maize for resistance to stalk rot.
基金supported by the National Natural Science Foundation of China(No.32071980)the Key Projects of Shaanxi Agricultural Collaborative Innovation and Extension Alliance(No.LMZD202201)+1 种基金the Key R&D Project in Shaanxi Province(No.2021LLRH-07)Shaanxi Natural Scientific Basic Research Program project(No.2022JQ-157).
文摘Agricultural practices significantly contribute to greenhouse gas(GHG)emissions,necessitating cleaner production technologies to reduce environmental pressure and achieve sustainable maize production.Plastic film mulching is commonly used in the Loess Plateau region.Incorporating slow-release fertilizers as a replacement for urea within this practice can reduce nitrogen losses and enhance crop productivity.Combining these techniques represents a novel agricultural approach in semi-arid areas.However,the impact of this integration on soil carbon storage(SOCS),carbon footprint(CF),and economic benefits has received limited research attention.Therefore,we conducted an eight-year study(2015-2022)in the semi-arid northwestern region to quantify the effects of four treatments[urea supplied without plastic film mulching(CK-U),slow-release fertilizer supplied without plastic film mulching(CK-S),urea supplied with plastic film mulching(PM-U),and slow-release fertilizer supplied with plastic film mulching(PM-S)]on soil fertility,economic and environmental benefits.The results revealed that nitrogen fertilizer was the primary contributor to total GHG emissions(≥71.97%).Compared to other treatments,PM-S increased average grain yield by 12.01%-37.89%,water use efficiency by 9.19%-23.33%,nitrogen accumulation by 27.07%-66.19%,and net return by 6.21%-29.57%.Furthermore,PM-S decreased CF by 12.87%-44.31%and CF per net return by 14.25%-41.16%.After eight years,PM-S increased SOCS(0-40 cm)by 2.46%,while PM-U decreased it by 7.09%.These findings highlight the positive effects of PM-S on surface soil fertility,economic gains,and environmental benefits in spring maize production on the Loess Plateau,underscoring its potential for widespread adoption and application.
基金supported by the National Key Research and Development Program of China(2022YFD190160304 and 2018YFD0301206)Natural Science Foundation of Sichuan Province(2022NSFSC0013)Sichuan Provincial Maize Innovation Team Construction Project(SCCXTD-2023-02).
文摘A four-year field experiment was conducted with two cultivars and four N rate to investigate the spatiotemporal characteristics of leaf senescence in maize after silking and its response to N fertilizer rates on them,as well as to reveal the differences in post-silking chlorophyll degradation between low-N-tolerant cultivars.The results showed that the order of leaf senescence after silking in maize was lower leaf>upper leaf>ear leaf,leaf tip>middle>base.Increasing N fertilizer down-regulated the expression of ZmCLH2 and ZmPPH in the leaves at 10-30 d after silking,reducing CLH and PPH activities,thereby delaying the leaf senescence.These effects were more prominent in low-N-sensitive cultivar Xianyu 508(XY508)than in low-N-tolerant cultivar Zhenghong 311(ZH311),especially in the lower leaves and leaf tip.Under low N condition,leaf yellowing and chlorophyll degradation occurred later and slower in ZH311 than in XY508.This resulted in a higher post-silking dry matter accumulation and grain yield in ZH311,which may be one of the important physiological bases of low nitrogen tolerant cultivars.Future research should focus on developing low-N-tolerant maize cultivars with slower leaf senescence near the ear after silking.
基金supported by the National Key Research and Development Program of China(2021YFD1200703 and 2022YFF1001602)the National Science Foundation of China(32272024 and 32171940)+2 种基金the Pinduoduo-China Agricultural University Research Fund(PC2023B01001)the Chinese Universities Scientific Fund(2022TC142)the 2115 Talent Development Program of China Agricultural University。
文摘Maize(Zea mays),which is a vital source of food,feed,and energy feedstock globally,has significant potential for higher yields.However,environmental stress conditions,including drought and salt stress,severely restrict maize plant growth and development,leading to great yield losses.Leucine-rich repeat receptor-like kinases(LRR-RLKs)function in biotic and abiotic stress responses in the model plant Arabidopsis(Arabidopsis thaliana),but their roles in abiotic stress responses in maize are not entirely understood.In this study,we determine that the LRR-RLK ZmMIK2,a homolog of the Arabidopsis LRR-RK MALE DISCOVERER 1(MDIS1)-INTERACTING RECEPTOR LIKE KINASE 2(MIK2),functions in resistance to both drought and salt stress in maize.Zmmik2 plants exhibit enhanced resistance to both stresses,whereas overexpressing ZmMIK2 confers the opposite phenotypes.Furthermore,we identify C2-DOMAIN-CONTAINING PROTEIN 1(ZmC2DP1),which interacts with the intracellular region of ZmMIK2.Notably,that region of ZmMIK2 mediates the phosphorylation of ZmC2DP1,likely by increasing its stability.Both ZmMIK2 and ZmC2DP1 are mainly expressed in roots.As with ZmMIK2,knockout of ZmC2DP1 enhances resistance to both drought and salt stress.We conclude that ZmMIK2-ZmC2DP1 acts as a negative regulatory module in maize drought-and salt-stress responses.
基金supported by the Natural Science Fund of China(31771724)the Key Research and Development Project of Shaanxi Province(2024NC-ZDCYL-01-10).
文摘The increase in soil temperature associated with climate change has introduced considerable challenges to crop production.Split nitrogen application(SN)represents a potential strategy for improving crop nitrogen use efficiency and enhancing crop stress resistance.Nevertheless,the precise interaction between soil warming(SW)and SN remains unclear.In order to ascertain the impact of SW on maize growth and whether SN can improve the tolerance of maize to SW,a two-year field experiment was conducted(2022-2023).The aim was to examine the influence of two SW ranges(MT,warming 1.40℃;HT,warming 2.75℃)and two nitrogen application methods(N1,one-time basal application of nitrogen fertilizer;N2,one third of base nitrogen fertilizer+two thirds of jointing stage supplemental nitrogen fertilizer)on maize root growth,photosynthetic characteristics,nitrogen use efficiency,and yield.The results demonstrated that SW impeded root growth and precipitated the premature aging of maize leaves following anthesis,particularly in the HT,which led to a notable reduction in maize yield.In comparison to N1,SN has been shown to increase root length density by 8.54%,root bleeding rate by 8.57%,and enhance root distribution ratio in the middle soil layers(20-60 cm).The interaction between SW and SN had a notable impact on maize growth and yield.The SN improved the absorption and utilization efficiency of nitrogen by promoting root development and downward canopy growth,thus improving the tolerance of maize to SW at the later stage of growth.In particular,the N2HT resulted in a 14.51%increase in the photosynthetic rate,a 18.58%increase in nitrogen absorption efficiency,and a 18.32%increase in maize yield compared with N1HT.It can be posited that the SN represents a viable nitrogen management measure with the potential to enhance maize tolerance to soil high-temperature stress.
文摘Maize value-added products play a crucial role in reducing post-harvest losses, enhancing food security, and generating income. While extensive research has focused on maize production in Cameroon, the exploration of its value-added products and their profitability in the North-West Region remains underexplored. This study examined the profitability of maize value-added products in Mezam Division, with the objectives to: 1) identify various maize-based products, 2) assess the diversity of these products, 3) conduct a cost-benefit analysis of selected products, 4) examine the relationship between profitability and product diversity, and 5) identify key constraints impacting profitability. To achieve these objectives, structured questionnaires were administered to 500 small-scale maize entrepreneurs randomly selected from five subdivisions. Descriptive statistics were used to analyze objective 1 and 5, while the Shannon Diversity Index was employed to assess product diversity. Additionally, a cost-benefit analysis was conducted on four selected products namely pap, parched corn, peeled parboiled corn, and corn beer, and a correlation analysis was used to examine objective 4. In total, 13 maize value-added products were identified, with a diversity index of 4.4. The total cost of processing the four selected products per entrepreneur using 18 kg of maize per product was FCFA 83631.5 (US $132.75), while the total revenue was FCFA 121864.5 (US $193.43), resulting in an economic profit of FCFA 38,233 (US $60.69). Pap emerged as the most profitable product, with an economic profit of FCFA 27,875 (US $44.24), while corn beer was the least profitable, with an economic profit of FCFA 2133.46 (US $3.39). The correlation analysis revealed a strong negative relationship between product diversity and profitability (r = −0.91), indicating that entrepreneurs can maximize profitability by focusing on a few high-demand products like pap and parched corn. Key constraints to profitability included fluctuating market prices, high production costs, limited access to finance, and inadequate storage facilities. Despite these challenges, our findings indicate that maize value addition is profitable in Mezam Division. Entrepreneurs can leverage this data for informed decision-making and future investments. It is recommended that the government promote maize value addition and provide financial support for modern processing equipment to boost profitability and income generation.
基金supported by the National Natural Science Foundation of China(32072126 and 32230075)the Shandong Provincial Natural Science Foundation(ZR2019MC005).
文摘Pentatricopeptide repeat(PPR)proteins are a large group of eukaryote-specific RNA-binding proteins that play pivotal roles in plant organelle gene expression.Here,we report the function of PPR21 in mitochondrial intron splicing and its role in maize kernel development.PPR21 is a typical P-type PPR protein targeted to mitochondria.The ppr21 mutants are arrested in embryogenesis and endosperm development,leading to embryo lethality.Null mutations of PPR21 reduce the splicing efficiency of nad2 intron 1,2,and 4 and impair the assembly and activity of mitochondrial complex I.Previous studies show that the P-type PPR protein EMP12 is required for the splicing of identical introns.However,our protein interaction analyses reveal that PPR21 does not interact with EMP12.Instead,both PPR21 and EMP12 interact with the small MutS-related(SMR)domain-containing PPR protein 1(PPR-SMR1)and the short P-type PPR protein 2(SPR2).PPR-SMR1 interacts with SPR2,and both proteins are required for the splicing of many introns in mitochondria,including nad2 intron 1,2,and 4.These results suggest that a PPR21-(PPR-SMR1/SPR2)-EMP12 complex is involved in the splicing of nad2 introns in maize mitochondria.
文摘Maize is an important source of calories and protein in human lives in many countries of the world and is the main staple food in Africa, particularly in eastern Africa. In the Sudan, the low yield of maize was mainly due to the use of low yielding landraces. It is necessary to carry out breeding programs that deal with the production of high yielding, adaptable new varieties. Therefore, this study aimed to estimate genetic variability, heritability, genotypic performance and interrelationships among the traits. Ten maize genotypes evaluated at White Nile Research Station Farm, Kosti, of the Agricultural Research Corporation (ARC), Wad Medani Sudan were planted in a randomized complete block design with three replications during the two seasons of 2021 and 2022. Most evaluated genotypes exhibited a wide and significant variation in the 11 measured traits. Genotypic coefficient of variation and genetic advance were recorded for days to 50% tasseling, ear diameter (cm), number of grains per row and grain yield (t/ha) in both seasons. High heritability and genetic advance were recorded for grain yield, ear length, ear height, plant height, number of rows per ear, ear weight, days to 50% tasseling, 100-grain weight and days to 50% silking. Moreover, there was a highly significant and positive correlation of grain yield with number of rows per ear (r = 0.479), ear length (r = 0.381), 100-grain weight (r = 0.344) and days to 50% tasseling (r = 0.214). The highest yielding five genotypes across the seasons were TZCOM1/ZDPSYN (4.2 t/ha), EEPVAH-3 (4.2 t/ha), F2TWLY131228 (4.1 t/ha), PVA SYN6F2 (3.9 t/ha) and EEPVAH-9 (3.8 t/ha) these were needed to check the adaptability, stability and to test major maize growing areas to make sound recommendations for release.
文摘Twenty short-statured maize inbred lines were collected from CIMMYT India and Mexico through the Plant Breeding Division, Bangladesh Agricultural Research Institute (BARI), Gazipur. The experiment was conducted from November 2020 to April 2021 in three different agroecological regions such as BARI, Gazipur, RARS Barisal and RARS Rangpur. Seven inbred lines were selected on the basis of genetic diversity and per se performance and they were crossed separately in a 7 × 7 half diallel fashion, producing 21F1 hybrids in 2019 which were evaluated at three locations. However, variances due to GCA were much higher in magnitude than SCA for all the characters indicating preponderance of additive gene effects on the inheritance of these characters. Two parents viz., P3 (CML33) and P4 (CML41) were good general combiners and two crosses viz., P4 × P5 (CML41 × CML31) and P5 × P7 (CML31 × CML124) expressed significant positive SCA effects coupled with significant positive heterosis for grain yield and for most of the yield contributing characters over the two commercial check varieties BHM 9 and NK40. Four crosses: P1 × P5 (CML116 × CML31), P1 × P6 (CML116 × CML32), P2 × P6 (CML72 × CML32) and P3 × P4 (CML33 × CML41), exhibited significant and negative SCA effects for both plant and ear height which were desirable for short stature. Genotypes x location interaction was also significant for maximum characters, suggesting that genotypes interacted significantly in different environments.
文摘Smallholder farming in West Africa faces various challenges, such as limited access to seeds, fertilizers, modern mechanization, and agricultural climate services. Crop productivity obtained under these conditions varies significantly from one farmer to another, making it challenging to accurately estimate crop production through crop models. This limitation has implications for the reliability of using crop models as agricultural decision-making support tools. To support decision making in agriculture, an approach combining a genetic algorithm (GA) with the crop model AquaCrop is proposed for a location-specific calibration of maize cropping. In this approach, AquaCrop is used to simulate maize crop yield while the GA is used to derive optimal parameters set at grid cell resolution from various combinations of cultivar parameters and crop management in the process of crop and management options calibration. Statistics on pairwise simulated and observed yields indicate that the coefficient of determination varies from 0.20 to 0.65, with a yield deviation ranging from 8% to 36% across Burkina Faso (BF). An analysis of the optimal parameter sets shows that regardless of the climatic zone, a base temperature of 10˚C and an upper temperature of 32˚C is observed in at least 50% of grid cells. The growing season length and the harvest index vary significantly across BF, with the highest values found in the Soudanian zone and the lowest values in the Sahelian zone. Regarding management strategies, the fertility mean rate is approximately 35%, 39%, and 49% for the Sahelian, Soudano-sahelian, and Soudanian zones, respectively. The mean weed cover is around 36%, with the Sahelian and Soudano-sahelian zones showing the highest variability. The proposed approach can be an alternative to the conventional one-size-fits-all approach commonly used for regional crop modeling. Moreover, it has the potential to explore the performance of cropping strategies to adapt to changing climate conditions.
文摘Increasing concern over the amount of insecticide residues in food has encouraged research for ecologically sound strategies to effectively manage stored-product insect pests and protect living organisms and the environment. Botanicals were evaluated as potential alternatives to control maize weevil, Sitophilus zeamais Motschulsky, in stored sorghum, Sorghum bicolor (L.) Moench. Beetles and moths of stored grain at farm and consumer levels damage 5 - 35% worldwide and >40% in tropical countries. Maize weevil is the most damaging storage insect of sorghum grain. Management of storage insects relies on insecticides that leave residues in food and the environment. Treatments were powders of neem bark, Azadirachta indica;mesquite pods, Prosopis glandulosa;milkweed leaves, Asclepias speciosa;and a check (no botanical powder). Eight newly emerged maize weevils were provided 5 g of Malisor-84 grain treated with three doses of each plant powder. Every 2 days, data were recorded on the number of adults killed by each treatment. Percentage killed was calculated by dose per treatment and compared with the check. Grain loss was calculated based on initial and final weights. LD50 was determined by probit analysis, and associations between variables were assessed by simple linear correlation. Powder of mesquite and milkweed at 0.2 g were more effective than neem or the check in killing S. zeamais (>90%) and reducing grain damage (34 - 35.2%) and weight loss (0.8%). Milkweed at 0.1 g and neem at 0.2 g killed 78.1% of weevils. Neem at 0.05 g was slow acting, resulting in 62.5% dead and more grain damage (59.5%) and weight loss (3.6%). Botanicals at low doses (LD50 = 0.2 - 0.4 g) showed efficacy in controlling maize weevils and are recommended alternatives to guarantee quantity and quality of stored cereal grains.
文摘Maize (Zea mays L.) is the world’s leading cereal crop, with production estimated at over 1 billion tonnes in 2022. In Côte d’Ivoire, maize is one of the most widely consumed foods, with national production exceeding 1 million tonnes in 2022. Despite its importance, this crop is subject to numerous biotic constraints, including Maize streak virus (MSV). The objective of this study was to characterize MSV isolates from Côte d’Ivoire using molecular biology techniques. To achieve this, maize leaf samples displaying characteristic symptoms of MSV were collected from different agro-ecological zones (AEZs) of Côte d’Ivoire. Total DNA was extracted from the collected samples using the CTAB method and quantified with a Nanodrop spectrophotometer. The C2 region of the MSV genome’s open reading frame (ORF) was amplified through polymerase chain reaction (PCR) using MSV-specific primers. The resulting PCR products were sequenced using the Sanger method. Bioinformatics analysis was performed using MSV sequences from other African countries (retrieved from NCBI) alongside sequences obtained in this study. The analysis was conducted using MEGA X version 10.05 software. The results showed that the main symptoms observed in the field included the presence of longitudinal light green streaks on leaves, stunted plant growth, and incomplete seed development in infected plants. Phylogenetic analysis of the sequences from Côte d’Ivoire revealed three monophyletic groups, with sequences of some isolates collected from the same plot belonging to different groups. The MSV sequences from Côte d’Ivoire are very close to those from Rwanda. This study underscores the need for further investigation into the genetic diversity of MSV strains to enhance the diagnosis and management of this viral disease, which is particularly prevalent in maize crops in Côte d’Ivoire.
基金supported by the Science and Technology Development Plan Project of Jilin Provincial Department of Science and Technology (No.20220203112S)the Jilin Provincial Department of Education Science and Technology Research Project (No.JJKH20210039KJ)。
文摘In this study,eight different varieties of maize seeds were used as the research objects.Conduct 81 types of combined preprocessing on the original spectra.Through comparison,Savitzky-Golay(SG)-multivariate scattering correction(MSC)-maximum-minimum normalization(MN)was identified as the optimal preprocessing technique.The competitive adaptive reweighted sampling(CARS),successive projections algorithm(SPA),and their combined methods were employed to extract feature wavelengths.Classification models based on back propagation(BP),support vector machine(SVM),random forest(RF),and partial least squares(PLS)were established using full-band data and feature wavelengths.Among all models,the(CARS-SPA)-BP model achieved the highest accuracy rate of 98.44%.This study offers novel insights and methodologies for the rapid and accurate identification of corn seeds as well as other crop seeds.
基金supported by the National Key Research and Development Program of China(2021YFF1000504 and 2023YFD1901300)the National Natural Science Foundation of China(32172658,32172659 and 32302662)the Natural Science Foundation of Guangdong Province,China(2021A1515010826).
文摘Maize/soybean intercropping systems are commonly used in developing countries,but few studies have been performed to elucidate the differences in nutrient efficiency and rhizosphere microbiome,especially when maize is intercropped with different soybean varieties.In this study,field experiments were conducted to compare the growth and yield of two soybean(Glycine max)varieties,BD2 and YC03-3,and one maize(Zea mays)variety,Huazhen,in mono-cropped and intercropped cultures.The plant biomass and N content of both crops in BD2/maize intercropping were significantly improved compared to their monoculture,but no such effects were observed in the plants of YC03-3/maize intercropping.The yield of BD2 intercropped with maize exhibited a 37.5%increment above that of BD2 in monoculture.Moreover,19.2-29.1%longer root length of maize and 19.0-39.4%larger root volume of BD2 were observed in BD2/maize intercropping than in monoculture,but no growth advantage was observed in YC03-3/maize intercropping.Maize showed root avoidance when intercropped with BD2,but space competition when intercropped with YC03-3.16S rRNA amplicon sequencing showed that compared with the monoculture system,rhizobacteria community composition in BD2/maize intercropping changed more significantly than that of the YC03-3/maize intercropping system.In BD2/maize intercropping,most of the rhizobacteria community biomarker bacteria of BD2 were positively correlated with plant biomass,as well as plant P and N content.Maize tended to recruit Rhizobiales and Proteobacteria,which showed positive correlation with plant biomass and N content,respectively,as well as soil available N.In conclusion,soybean varieties determined the advantages of maize/soybean intercropping through root-root interactions and modification of rhizobacteria communities.Our insight emphasizes a linkage between root traits and the rhizobacteria community,which shows the importance of optimizing intercropping systems by selection of appropriate crop varieties.
基金supported by the Key Research and Development Project of Heilongjiang Province(2022ZX02B01)the Natural Science Foundation Project of Heilongjiang Province(YQ2022C009)the Natural Science Foundation of Shandong Province(K22LB56)。
文摘Maize(Zea mays L.),a globally significant cereal crop,is produced in vast quantities worldwide.However,its growth is severely constrained by low temperatures,particularly during seed germination,which significantly impairs seedling emergence.In this study,genetic diversity across six germination-associated phenotypic traits(RGR,RSL,RTL,RRSA,RRV,and RSVI)of 304 inbred lines was analyzed,to evaluate the capacity of these lines for low-temperature tolerance.Genome-wide association study(GWAS)was carried out by combining six germination-associated phenotypic traits and genotypic data from 30-fold resequencing.The gene ZmBARK1 was identified through integrated GWAS and RNA-seq analyses,and its association with low-temperature tolerance during maize germination was validated by quantitative real-time PCR(qRT-PCR).ZmBARK1,encoding BRASSINOSTEROID INSENSITIVE 1-associated receptor kinase 1,was located on the bin 4.09 region of maize chromosome 4.Amino acid comparison and subcellular localization analyses revealed that ZmBARK1 is highly homologous to AtBAK1 and is localized to the plasma membrane of the cell,which may be involved in regulating brassinosteroid(BR)signaling.In addition,we revealed the role of ZmBARK1 in low-temperature tolerance during maize germination.Compared with wild-type(WT),the ethyl methanesulfonate(EMS)mutant zmbark1 was characterized by substantially enhanced low-temperature tolerance.Overall,these findings provide promising candidate genes,improve low-temperature tolerance in maize,and advance the understanding of regulatory mechanisms underlying maize's response to low-temperature stress.
基金funded by the National Science and Technology Major Project(2022ZD0115703)the Beijing Postdoctoral Research Foundation(2023-ZZ-116).
文摘The environment has an important impact on maize(Zea mays L.)production,making it necessary to identify plant adaptation regions that are suitable for different maize varieties.Traditional methods using field trials are costly and restricted to a limited number of areas.Identifying adaptation regions based on climate data has great potential,but a basic understanding and a prediction approach for diverse maize varieties are lacking.Here,we collected a representative dataset comprising 32,840 data points from the National Maize Variety Trial Data Management Platform.We employed three traits to characterize the adaptability of different maize varieties:PH(plant height),DTS(days to silking),and yield.First,we quantified the contributions of variety(V),environment(E),and V×E to variance in the three adaptationrelated traits.The mean contributions of E to variance in PH,DTS,and yield were 54.50%,82.87%,and 75.92%,respectively,suggesting that environmental effects are crucial for phenotype construction.Second,we analyzed correlations between the three traits and three environmental indices:GDD(growing degree days),PRE(precipitation),and SSD(sunshine duration).The highest absolute correlation coefficients between phenotypes and environmental indices were 0.15–0.69 at the whole-data level.To predict variety adaptation on a national scale,we modeled the three traits using environmental indices and best linear unbiased predictors(BLUPs)via the random forest algorithm.The predictive abilities of our models for PH,DTS,and yield were 0.90(MAE=9.95 cm),0.99(MAE=1.09 d),and 0.95(MAE=0.55 t ha^(−1)),respectively,indicating that our proposed framework can predict adaptationrelated traits for diverse maize varieties in China.
基金supported by the National Natural Science Foundation of China(32101700)the China Postdoctoral Science Foundation(2022M7111220)+1 种基金the Science and Technology Innovation Program of Hunan Province,China(2021RC2082)and the Postgraduate Scientific Research Innovation Project of Hunan Province,China(CX20230697)。
文摘Crude fat is an important nutritional component of maize kernels.However,the genetic mechanisms underlying crude fat content in maize kernels remain elusive.Previous studies used single-model genome-wide association studies(GWAS)with limited population sizes,which can result in false loci positives and hinder functional gene identification.Therefore,this study used a population consisting of 495 maize inbred lines,combined with 1.25 million single nucleotide polymorphisms(SNPs),and implemented GWAS using six models to identify quantitative trait nucleotides(QTNs)controlling crude fat content and to mine key genes.The results revealed a wide variation in crude fat content(0.62-16.03%)and broad-sense heritability(H^(2))(96.23%).In total,744 significant QTNs were detected,with 147 co-located across different models,environments,and methods.Based on the 147 colocated QTNs,candidate genes were searched at 50 kb up-and down-stream intervals of each QTN.We finally screened eight candidate genes(GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,GRMZM2G368838,GRMZM2G058496,GRMZM2G090669,GRMZM2G001241,and GRMZM2G333454)related to crude fat content that exhibited high expression levels during kernel development in maize inbred line B73.Notably,GRMZM2G169089,GRMZM2G117935,GRMZM2G002075,and GRMZM2G368838 are involved in the linoleic acid metabolic pathway,oil metabolism,kernel growth,and development in maize.Furthermore,co-expression network analysis revealed that the eight candidate genes strongly correlated with 30 known genes.Proteins encoded by candidate genes interact with other proteins and play an important role in oil content and oleic acid metabolism in maize kernels.The best haplotypes of candidate genes might increase crude fat content without decreasing maize yield.These results broaden the understanding of the genetic mechanism of crude fat content and facilitate marker-assisted selection for high-crude fat breeding programs for maize.
基金supported by National Key Research and Development Program of China(2022YFF1003501)Biological BreedingMajor Projects(2023ZD04076)+1 种基金Funds from State Key Laboratory of Maize Bio-breeding(SKLMB2404,SKLMB2440)Anhui Natural Science Foundation(2308085QC92).
文摘Meiosis,a critical process for sexual reproduction,requires precise regulation to ensure the correct progression of meiotic stages.In yeast and animals,errors in meiotic recombination and homologous chromosomes synapsis bring a surveillance mechanism named pachytene checkpoint to prevent pachytene exit.However,most plant mutants with defects in meiotic prophase I continue cell cycle progression,which hindered the characterization of factors controlling the prophase I to metaphase I transition.Here,we characterized a male-sterile mutant in maize,prolonged prophase1(pp1),which exhibited pachytene and diakinesis arrest in male meiosis,and abnormal chromatin condensation.Using mapbased cloning,the PP1 gene was isolated as a PHD family transcription factor,and its transcripts of PP1 were preferentially accumulated in tapetum and male germline cells during microsporogenesis.Transcriptomic analysis of the pp1 mutant revealed downregulation of genes associated with chromatin assembly,cell cycle,and male meiosis,correlating with observed meiotic arrest and chromatin condensation defects.These findings highlight the role of PP1 in maize microsporogenesis,and providing more insights into the mechanisms regulating the meiotic progression in maize.
基金supported by Youth Scientific Research Foundation of Beijing Academy of Agriculture and Forestry Sciences (QNJJ202208)the Collaborative Innovation Center of Beijing Academy of Agriculture and Forestry Sciences (KJCX20240408)+1 种基金Major Scientific and Technological Achievements Cultivation Project of Beijing Academy of Agriculture and Forestry SciencesNational Natural Science Foundation of China (32201815)。
文摘One-third of the global population is affected by micronutrient deficiency, particularly folate. Although folate synthesis has been relatively well characterized, few folate-related genes in maize have been cloned, and the molecular mechanism regulating folate synthesis in maize remains unclear. In this study,transcriptome and proteome analyses of three waxy maize inbred lines with high, medium, and low folate contents were performed to identify key genes controlling folate biosynthesis. Pairwise comparisons revealed 21 differentially expressed genes and 20 differentially expressed proteins potentially associated with folate biosynthesis in the three lines. Six key folate-associated genes, Zm Mocos2, Zm GGH,Zm ADCL2, Zm CBR1, Zm SHMT, and Zm Pur H, were identified. These genes encode enzymes that potentially function in folate biosynthesis. Functional validation of one of these genes, Zm ADCL2, using an EMS mutant(Mut9264) showed that a 4-base insertion in an exon increased the folate content of fresh maize kernels 1.37-fold that of the wild type. Zm ADCL2 was considered a potential target for generating maize lines with higher folate content. KEGG enrichment analysis of differentially expressed genes and proteins showed that several pathways in addition to folate biosynthesis were likely indirectly involved in folate metabolism and content(e.g., glycine, serine, and threonine metabolism;purine metabolism;cysteine and methionine metabolism;alanine, aspartate and glutamate metabolism;glutathione metabolism;and pyruvate metabolism. The transcriptome and proteomic data generated in this study will help to clarify the mechanisms underlying folate accumulation and aid breeding efforts to biofortify maize with folate.
