Globally, one of the most devastating diseases of sorghum is anthracnose incited by Colletotrichum sublineola. During the 2019 and 2020 growing seasons, 94 and 64 accessions from the Ethiopian sorghum germplasm collec...Globally, one of the most devastating diseases of sorghum is anthracnose incited by Colletotrichum sublineola. During the 2019 and 2020 growing seasons, 94 and 64 accessions from the Ethiopian sorghum germplasm collection maintained by the National Genetic Resources Program of the United States Department of Agriculture were evaluated for anthracnose resistance. Seeds were planted in 1.8 m rows with 0.9 m row spacing in a randomized complete block design. The accessions and checks were replicated three times and 30 days after planting, inoculated by placing C. sublineola-colonized grains in the plant whorls. A total of 30 accessions, including PI533918, PI533923, PI534131 and PI534151 were resistant to the disease in both years. These identified resistant sources can be used in breeding programs to develop anthracnose-resistant lines and hybrids.展开更多
Ethylenediurea(EDU)has been used as a chemical protectant against ozone(O3).However,its protective effect and physiological mechanisms are still uncertain.The present study aimed to investigate the changes of foliar v...Ethylenediurea(EDU)has been used as a chemical protectant against ozone(O3).However,its protective effect and physiological mechanisms are still uncertain.The present study aimed to investigate the changes of foliar visible injury,physiological characteristics and emission rates of volatile organic compounds(VOCs)in one-year-old Populus alba"Berolinensis"saplings pretreated with EDU and exposed to elevated O3(EO,120μg/m3).The results showed that foliar visible injury symptoms under EO were significantly alleviated in plants with EDU application(p<0.05).Under EO,net photosynthetic rate,the maximum photochemical efficiency of PSII and the photochemical efficiency of PSII of plants pretreated with 300 and600 mg/L EDU were similar to unexposed controls and significantly higher compared to EOstressed plants without EDU pretreatment,respectively.Malondialdehyde content was highest in EO without EDU and decreased significantly by 14.9%and 21.3%with 300 and600 mg/L EDU pretreatment,respectively.EDU pretreatment alone increased superoxide dismutase activity by 10-fold in unexposed plants with further increases of 88.4%and 37.5%in EO plants pretreated with 300 and 600 mg/L EDU pretreatment,respectively(p<0.05).Abscisic acid content declined under EO relative to unexposed controls with the effect partially reversed by EDU pretreatments.Similarly,VOCs emission rate declined under EO relative to unexposed plants with a recovery of emission rate observed with 300 and 600 mg/L EDU pretreatment.These findings provided significant evidence that EDU exerted a beneficial effect and protection on the tested plants against O3 stress.展开更多
Wheat powdery mildew(Blumeria graminis f.sp.tritici, Bgt) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies.Growing resistant cul...Wheat powdery mildew(Blumeria graminis f.sp.tritici, Bgt) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies.Growing resistant cultivars is a preferred approach to managing this disease, and novel powdery mildew resistance genes are urgently needed for new cultivar development.A genome-wide association study was performed on a panel of 1292 wheat landraces and historical cultivars using 5011 single nucleotide polymorphism(SNP)markers.The association panel was evaluated for reactions to three Bgt inoculants, OKS(14)-B-3-1, OKS(14)-C-2-1, and Bgt15.Linkage disequilibrum(LD) analysis indicated that genome-wide LD decayed to 0.1 at 23 Mb, and population structure analysis revealed seven subgroups in the panel.Association analysis using a mixed linear model(MLM) identified three loci for powdery mildew resistance on chromosome 2 B, designated QPm.stars-2BL1,QPm.stars-2BL2, and QPm.stars-2BL3.To evaluate the efficacy of GWAS in gene discovery,QPm.stars-2BL2 was validated using F2 and F2:3 populations derived from PI420646 × OK1059060-126135-3.Linkage analysis delimited the powdery mildew resistance gene in PI 420646 to an interval where QPm.stars-2BL2 was located, lending credence to the GWAS results.QPm.stars-2BL1 and QPm.stars-2BL3, which were associated with four SNPs located at 457.7–461.7 Mb and two SNPs located at 696.6–715.9 Mb in the Chinese Spring reference IWGSC RefSeq v1.0, respectively, are likely novel loci for powdery mildew resistance and can be used in wheat breeding to improve powdery mildew resistance.展开更多
Tropospheric ozone（O3） is a major air pollutant and causes serious injury to vegetation. To protect sensitive plants from O3 damage, several agrochemicals have been assessed,including cytokinin（e.g., kinetin, KIN）...Tropospheric ozone（O3） is a major air pollutant and causes serious injury to vegetation. To protect sensitive plants from O3 damage, several agrochemicals have been assessed,including cytokinin（e.g., kinetin, KIN） and ethylenediurea（EDU） with cytokinin-like activity.In higher plant, leaves are primarily injured by O3 and protective agrochemicals are often applied by leaf spraying. To our knowledge, the mitigating abilities of EDU and KIN have not been compared directly in a realistic setup. In the present research, impacts of elevated O3（2 × ambient O3, 24 hr per day, for 8 days） on an O3 sensitive line（S156） of snap bean（Phaseolus vulgaris）, which is often used for biomonitoring O3 pollution, were studied in a free air controlled exposure system. The day before starting the O3 exposure, plants were sprayed with a solution of EDU（300 ppm）, KIN（1 mmol/L） or distilled water, to compare their protective abilities. The results demonstrated that 2 × ambient O3 inhibited net photosynthetic rate and stomatal conductance, increased the minimal fluorescence yield of the dark-adapted state, decreased the maximal quantum yield of PSII photochemistry, and led to visible injury. KIN and EDU alleviated the reduction of the photosynthetic performance, and visible injury under O3 fumigation. The plants sprayed with EDU showed greater ability to mitigate the O3 damage than those sprayed with KIN. Chlorophyll fluorescence imaging may have detected more precisely the differences in O3 response across the leaf than the conventional fluorometer.展开更多
The cross-linked nature of plant cell walls provides structural integrity for continued growth and development, but limits degradation and utilization by ruminants. In grasses a major cross-linking component is feruli...The cross-linked nature of plant cell walls provides structural integrity for continued growth and development, but limits degradation and utilization by ruminants. In grasses a major cross-linking component is ferulic acid that is incorporated into cell walls as an ester linked residue on arabinoxylans. Ferulates can become coupled to each other and to lignin forming a highly cross-linked matrix of carbohydrates and lignin. Seedling ferulate ester mutants (sfe) were produced in maize using the transposon system and evaluated in feeding trials. The work described here was undertaken to characterize changes in the ferulate cross-linked nature as well as other components of the corn cell wall matrix in leaf, sheath and stem tissues. Total ferulates decreased modestly due to the mutation and were more apparent in leaf tissue (16% - 18%) compared to sheath (+5 to?-6% change) and stem (8% - 9% decrease). The most significant changes were in the ether linked ferulates to lignin, both monomer and dehydrodiferulates (14% to 38% decrease). Other characteristics of the cell wall (lignin, neutral sugar composition) also showed modest changes. The change in total ferulates was modest, but led to improved animal performance. These findings suggest that relatively small changes can have a significant impact upon how well plant materials can be broken down and utilized by ruminants such as dairy cows.展开更多
North Africa is one of the most regions impacted by water shortage.The implementation of controlled drainage(CD)in the northern Nile River delta of Egypt is one strategy to decrease irrigation,thus alleviating the neg...North Africa is one of the most regions impacted by water shortage.The implementation of controlled drainage(CD)in the northern Nile River delta of Egypt is one strategy to decrease irrigation,thus alleviating the negative impact of water shortage.This study investigated the impacts of CD at different levels on drainage outflow,water table level,nitrate loss,grain yield,and water use efficiency(WUE)of various wheat cultivars.Two levels of CD,i.e.,0.4 m below the soil surface(CD-0.4)and 0.8 m below the soil surface(CD-0.8),were compared with subsurface free drainage(SFD)at 1.2 m below the soil surface(SFD-1.2).Under each drainage treatment,four wheat cultivars were grown for two growing seasons(November 2018–April 2019 and November 2019–April 2020).Compared with SFD-1.2,CD-0.4 and CD-0.8 decreased irrigation water by 42.0%and 19.9%,drainage outflow by 40.3%and 27.3%,and nitrate loss by 35.3%and 20.8%,respectively.Under CD treatments,plants absorbed a significant portion of their evapotranspiration from shallow groundwater(22.0%and 8.0%for CD-0.4 and CD-0.8,respectively).All wheat cultivars positively responded to CD treatments,and the highest grain yield and straw yield were obtained under CD-0.4 treatment.Using the initial soil salinity as a reference,the soil salinity under CD-0.4 treatment increased two-fold by the end of the second growing season without negative impacts on wheat yield.Modifying the drainage system by raising the outlet elevation and considering shallow groundwater contribution to crop evapotranspiration promoted water-saving and WUE.Different responses could be obtained based on the different plant tolerance to salinity and water stress,crop characteristics,and growth stage.Site-specific soil salinity management practices will be required to avoid soil salinization due to the adoption of long-term shallow groundwater in Egypt and other similar agroecosystems.展开更多
This study addressed the escalating demand for aquatic feed by exploring the potential of alfalfa nutrient concentrate(ANC) as feed ingredient for rainbow trout. Test diets contained varying ANC levels(0%, 5%,10%, 15%...This study addressed the escalating demand for aquatic feed by exploring the potential of alfalfa nutrient concentrate(ANC) as feed ingredient for rainbow trout. Test diets contained varying ANC levels(0%, 5%,10%, 15%, and 20%) to replace fishmeal(32% in the 0% ANC diet) to achieve equal digestible protein and were processed using a cooking extrusion method. Analysis of feed pellets showed that pellet density increased with ANC levels(P < 0.001), resulting in sinking pellets at 20% ANC. Water stability and durability were improved while oil leakage decreased with increasing ANC levels(P < 0.05). Two feeding trials were conducted to test the diets in flow-through water systems with three replicates per diet. The first 10-week trial evaluated their impact on feeding, fecal physical quality, and the apparent digestibility coefficient(ADC) of dietary nutrients in rainbow trout(initial body weight 18.0 ± 0.2 g). ANC inclusion did not impact the palatability and satiety feed intake of the fish(P > 0.05). However, the ADC of dry matter and phosphorus significantly decreased in fish fed the 20% ANC diet(P < 0.05). The second 9-week trial investigated the growth performance, nutrition quality, and metabolism of rainbow trout(initial body weight 19.0 ± 0.2 g). While all fish exhibited substantial growth, fish fed diets with 10% to20% ANC displayed lower specific growth rate and higher feed conversion ratio compared to those fed with 0% or 5% ANC(P < 0.05). The whole body protein content was higher in fish fed 5% ANC compared to all other treatments(P = 0.030). The biochemical parameters of plasma were similar across treatments,except for a decrease in plasma phosphorus levels in fish fed a 10% ANC diet compared to those fed a 0%ANC diet(P = 0.033). Significant changes were observed in liver metabolism including tricarboxylic acid cycle, amino acid and energy metabolism pathways in fish fed the 20% ANC diet versus the 0% ANC diet(P < 0.05). These results demonstrate that ANC inclusion improved pellet physical quality without impairing feeding behavior and nutritional quality of the fish but inclusion ≥10% in the diet reduced fish growth. This study offers the first comprehensive assessment of the potential of ANC used in fish feed involving feed management, feeding evaluation, and the biological response.展开更多
The productivity, product quality and competitive ability of important agricultural and horticultural plants in many regions of the world may be adversely affected by current and anticipated concentrations of ground-l...The productivity, product quality and competitive ability of important agricultural and horticultural plants in many regions of the world may be adversely affected by current and anticipated concentrations of ground-level ozone （O_3）. Exposure to elevated O_3 typically results in suppressed photosynthesis, accelerated senescence, decreased growth and lower yields. Various approaches used to evaluate O_3 effects generally concur that current yield losses range from 5% to 15% among sensitive plants. There is, however, considerable genetic variability in plant responses to O_3.展开更多
In contrast to large-effect qualitative disease resistance,quantitative disease resistance(QDR)exhibits partial and generally durable resistance and has been extensively utilized in crop breeding.The molecular mechani...In contrast to large-effect qualitative disease resistance,quantitative disease resistance(QDR)exhibits partial and generally durable resistance and has been extensively utilized in crop breeding.The molecular mechanisms underlying QDR remain largely unknown but considerable progress has been made in this area in recent years.In this review,we summarize the genes that have been associated with plant QDR and their biological functions.Many QDR genes belong to the canonical resistance gene categories with predicted functions in pathogen perception,signal transduction,phytohormone homeostasis,metabolite transport and biosynthesis,and epigenetic regulation.However,other"atypical"QDR genes are predicted to be involved in processes that are not commonly associated with disease resistance,such as vesicle trafficking,molecular chaperones,and others.This diversity of function for QDR genes contrasts with qualitative resistance,which is often based on the actions of nucleotidebinding leucine-rich repeat(NLR)resistance proteins.An understanding of the diversity of QDR mechanisms and of which mechanisms are effective against which classes of pathogens will enable the more effective deployment of QDR to produce more durably resistant,resilient crops.展开更多
Automation of plant phenotyping using data from high-dimensional imaging sensors is on the forefront of agricultural research for its potential to improve seasonal yield by monitoring crop health and accelerating bree...Automation of plant phenotyping using data from high-dimensional imaging sensors is on the forefront of agricultural research for its potential to improve seasonal yield by monitoring crop health and accelerating breeding programs.A common challenge when capturing images in the field relates to the spectral reflection of sunlight(glare)from crop leaves that,at certain solar incidences and sensor viewing angles,presents unwanted signals.The research presented here involves the convergence of 2 parallel projects to develop a facile algorithm that can use polarization data to decouple light reflected from the surface of the leaves and light scattered from the leaf's tissue.展开更多
Maize is the world＇s most produced crop, providing food, feed, and biofuel. Maize production is constantly threatened by the presence of devastating pathogens worldwide. Characterization of the genetic compo- nents u...Maize is the world＇s most produced crop, providing food, feed, and biofuel. Maize production is constantly threatened by the presence of devastating pathogens worldwide. Characterization of the genetic compo- nents underlying disease resistance is a major research area in maize which is highly relevant for resistance breeding programs. Quantitative disease resistance （QDR） is the type of resistance most widely used by maize breeders. The past decade has witnessed significant progress in fine-mapping and cloning of genes controlling QDR. The molecular mechanisms underlying QDR remain poorly understood and exploited. In this review we discuss recent advances in maize QDR research and strategy for resistance breeding.展开更多
Seed size and composition are important traits in food crops and can be affected by nutrient availability in the soil. Phosphorus （P） is a non-renewable, essential macronutrient, and P deficiency limits soybean （G1...Seed size and composition are important traits in food crops and can be affected by nutrient availability in the soil. Phosphorus （P） is a non-renewable, essential macronutrient, and P deficiency limits soybean （G1ycine max） yield and quality. To investigate the associations of seed traits in low- and high-P environ- ments, soybean recombinant inbred lines （RILs） from a cross of cultivars Fiskeby III and Mandarin （Ottawa） were grown under contrasting P availability environments. Traits including individual seed weight, seed number, and intact mature pod weight were significantly affected by soil P levels and showed transgressive segregation among the RILs. Surprisingly, P treatments did not affect seed composition or weight, suggesting that soybeanmaintains sufficient P in seeds even in Iow-P soil. Quantitative trait loci （QTLs） were detected for seed weight, intact pods, seed volume, and seed protein, with five significant QTLs identified in Iow-P environments and one significant QTL found in the optimaI-P environment. Broad-sense heritability estimates were 0.78 （individual seed weight）, o.go （seed protein）, 0.34 （seed oil）, and 0.98 （seed number）. The QTLs identified under low P point to genetic regions that may be useful to improve soybean performance under limiting P conditions.展开更多
Active breeding programs specifically for root system architecture(RSA)phenotypes remain rare;however,breeding for branch and taproot types in the perennial crop alfalfa is ongoing.Phenotyping in this and other crops ...Active breeding programs specifically for root system architecture(RSA)phenotypes remain rare;however,breeding for branch and taproot types in the perennial crop alfalfa is ongoing.Phenotyping in this and other crops for active RSA breeding has mostly used visual scoring of specific traits or subjective classification into different root types.While image-based methods have been developed,translation to applied breeding is limited.展开更多
Plants defend themselves against microbial pathogens in several ways.Among the most important of these mechanisms are cyto-plasmic nucleotide-binding,leucine-rich repeat(NLR)resistance(R)proteins that are activated by...Plants defend themselves against microbial pathogens in several ways.Among the most important of these mechanisms are cyto-plasmic nucleotide-binding,leucine-rich repeat(NLR)resistance(R)proteins that are activated by direct or indirect interaction with pathogen-derived effector proteins introduced into the plant cell as part of the pathogenesis process.展开更多
文摘Globally, one of the most devastating diseases of sorghum is anthracnose incited by Colletotrichum sublineola. During the 2019 and 2020 growing seasons, 94 and 64 accessions from the Ethiopian sorghum germplasm collection maintained by the National Genetic Resources Program of the United States Department of Agriculture were evaluated for anthracnose resistance. Seeds were planted in 1.8 m rows with 0.9 m row spacing in a randomized complete block design. The accessions and checks were replicated three times and 30 days after planting, inoculated by placing C. sublineola-colonized grains in the plant whorls. A total of 30 accessions, including PI533918, PI533923, PI534131 and PI534151 were resistant to the disease in both years. These identified resistant sources can be used in breeding programs to develop anthracnose-resistant lines and hybrids.
基金supported by the National Natural Science Foundation of China (Nos. 41675153, 31870458, 31270518, 31170573, 31670412)
文摘Ethylenediurea(EDU)has been used as a chemical protectant against ozone(O3).However,its protective effect and physiological mechanisms are still uncertain.The present study aimed to investigate the changes of foliar visible injury,physiological characteristics and emission rates of volatile organic compounds(VOCs)in one-year-old Populus alba"Berolinensis"saplings pretreated with EDU and exposed to elevated O3(EO,120μg/m3).The results showed that foliar visible injury symptoms under EO were significantly alleviated in plants with EDU application(p<0.05).Under EO,net photosynthetic rate,the maximum photochemical efficiency of PSII and the photochemical efficiency of PSII of plants pretreated with 300 and600 mg/L EDU were similar to unexposed controls and significantly higher compared to EOstressed plants without EDU pretreatment,respectively.Malondialdehyde content was highest in EO without EDU and decreased significantly by 14.9%and 21.3%with 300 and600 mg/L EDU pretreatment,respectively.EDU pretreatment alone increased superoxide dismutase activity by 10-fold in unexposed plants with further increases of 88.4%and 37.5%in EO plants pretreated with 300 and 600 mg/L EDU pretreatment,respectively(p<0.05).Abscisic acid content declined under EO relative to unexposed controls with the effect partially reversed by EDU pretreatments.Similarly,VOCs emission rate declined under EO relative to unexposed plants with a recovery of emission rate observed with 300 and 600 mg/L EDU pretreatment.These findings provided significant evidence that EDU exerted a beneficial effect and protection on the tested plants against O3 stress.
文摘Wheat powdery mildew(Blumeria graminis f.sp.tritici, Bgt) is a disease of increasing importance globally due to the adoption of high yielding varieties and modern sustainable farming technologies.Growing resistant cultivars is a preferred approach to managing this disease, and novel powdery mildew resistance genes are urgently needed for new cultivar development.A genome-wide association study was performed on a panel of 1292 wheat landraces and historical cultivars using 5011 single nucleotide polymorphism(SNP)markers.The association panel was evaluated for reactions to three Bgt inoculants, OKS(14)-B-3-1, OKS(14)-C-2-1, and Bgt15.Linkage disequilibrum(LD) analysis indicated that genome-wide LD decayed to 0.1 at 23 Mb, and population structure analysis revealed seven subgroups in the panel.Association analysis using a mixed linear model(MLM) identified three loci for powdery mildew resistance on chromosome 2 B, designated QPm.stars-2BL1,QPm.stars-2BL2, and QPm.stars-2BL3.To evaluate the efficacy of GWAS in gene discovery,QPm.stars-2BL2 was validated using F2 and F2:3 populations derived from PI420646 × OK1059060-126135-3.Linkage analysis delimited the powdery mildew resistance gene in PI 420646 to an interval where QPm.stars-2BL2 was located, lending credence to the GWAS results.QPm.stars-2BL1 and QPm.stars-2BL3, which were associated with four SNPs located at 457.7–461.7 Mb and two SNPs located at 696.6–715.9 Mb in the Chinese Spring reference IWGSC RefSeq v1.0, respectively, are likely novel loci for powdery mildew resistance and can be used in wheat breeding to improve powdery mildew resistance.
基金supported by the National Natural Science Foundation of China (No. 31401895)‘Young Talents’ project of Northeast Agricultural University of China (No. 14Q10)+2 种基金financial support to the first author for his visiting research in Italy (No. 201606615002)The ozone FACE was financed by the Foundation Cassa di Risparmio of Florence (No. 2013/7956)supported in part by the LIFE15 ENV/IT/000183 project MOTTLES
文摘Tropospheric ozone（O3） is a major air pollutant and causes serious injury to vegetation. To protect sensitive plants from O3 damage, several agrochemicals have been assessed,including cytokinin（e.g., kinetin, KIN） and ethylenediurea（EDU） with cytokinin-like activity.In higher plant, leaves are primarily injured by O3 and protective agrochemicals are often applied by leaf spraying. To our knowledge, the mitigating abilities of EDU and KIN have not been compared directly in a realistic setup. In the present research, impacts of elevated O3（2 × ambient O3, 24 hr per day, for 8 days） on an O3 sensitive line（S156） of snap bean（Phaseolus vulgaris）, which is often used for biomonitoring O3 pollution, were studied in a free air controlled exposure system. The day before starting the O3 exposure, plants were sprayed with a solution of EDU（300 ppm）, KIN（1 mmol/L） or distilled water, to compare their protective abilities. The results demonstrated that 2 × ambient O3 inhibited net photosynthetic rate and stomatal conductance, increased the minimal fluorescence yield of the dark-adapted state, decreased the maximal quantum yield of PSII photochemistry, and led to visible injury. KIN and EDU alleviated the reduction of the photosynthetic performance, and visible injury under O3 fumigation. The plants sprayed with EDU showed greater ability to mitigate the O3 damage than those sprayed with KIN. Chlorophyll fluorescence imaging may have detected more precisely the differences in O3 response across the leaf than the conventional fluorometer.
文摘The cross-linked nature of plant cell walls provides structural integrity for continued growth and development, but limits degradation and utilization by ruminants. In grasses a major cross-linking component is ferulic acid that is incorporated into cell walls as an ester linked residue on arabinoxylans. Ferulates can become coupled to each other and to lignin forming a highly cross-linked matrix of carbohydrates and lignin. Seedling ferulate ester mutants (sfe) were produced in maize using the transposon system and evaluated in feeding trials. The work described here was undertaken to characterize changes in the ferulate cross-linked nature as well as other components of the corn cell wall matrix in leaf, sheath and stem tissues. Total ferulates decreased modestly due to the mutation and were more apparent in leaf tissue (16% - 18%) compared to sheath (+5 to?-6% change) and stem (8% - 9% decrease). The most significant changes were in the ether linked ferulates to lignin, both monomer and dehydrodiferulates (14% to 38% decrease). Other characteristics of the cell wall (lignin, neutral sugar composition) also showed modest changes. The change in total ferulates was modest, but led to improved animal performance. These findings suggest that relatively small changes can have a significant impact upon how well plant materials can be broken down and utilized by ruminants such as dairy cows.
文摘North Africa is one of the most regions impacted by water shortage.The implementation of controlled drainage(CD)in the northern Nile River delta of Egypt is one strategy to decrease irrigation,thus alleviating the negative impact of water shortage.This study investigated the impacts of CD at different levels on drainage outflow,water table level,nitrate loss,grain yield,and water use efficiency(WUE)of various wheat cultivars.Two levels of CD,i.e.,0.4 m below the soil surface(CD-0.4)and 0.8 m below the soil surface(CD-0.8),were compared with subsurface free drainage(SFD)at 1.2 m below the soil surface(SFD-1.2).Under each drainage treatment,four wheat cultivars were grown for two growing seasons(November 2018–April 2019 and November 2019–April 2020).Compared with SFD-1.2,CD-0.4 and CD-0.8 decreased irrigation water by 42.0%and 19.9%,drainage outflow by 40.3%and 27.3%,and nitrate loss by 35.3%and 20.8%,respectively.Under CD treatments,plants absorbed a significant portion of their evapotranspiration from shallow groundwater(22.0%and 8.0%for CD-0.4 and CD-0.8,respectively).All wheat cultivars positively responded to CD treatments,and the highest grain yield and straw yield were obtained under CD-0.4 treatment.Using the initial soil salinity as a reference,the soil salinity under CD-0.4 treatment increased two-fold by the end of the second growing season without negative impacts on wheat yield.Modifying the drainage system by raising the outlet elevation and considering shallow groundwater contribution to crop evapotranspiration promoted water-saving and WUE.Different responses could be obtained based on the different plant tolerance to salinity and water stress,crop characteristics,and growth stage.Site-specific soil salinity management practices will be required to avoid soil salinization due to the adoption of long-term shallow groundwater in Egypt and other similar agroecosystems.
基金funding from USDA-NIFA-ASAFS (2019-70005-30283)support from the China Scholarship Council (201906910073l)
文摘This study addressed the escalating demand for aquatic feed by exploring the potential of alfalfa nutrient concentrate(ANC) as feed ingredient for rainbow trout. Test diets contained varying ANC levels(0%, 5%,10%, 15%, and 20%) to replace fishmeal(32% in the 0% ANC diet) to achieve equal digestible protein and were processed using a cooking extrusion method. Analysis of feed pellets showed that pellet density increased with ANC levels(P < 0.001), resulting in sinking pellets at 20% ANC. Water stability and durability were improved while oil leakage decreased with increasing ANC levels(P < 0.05). Two feeding trials were conducted to test the diets in flow-through water systems with three replicates per diet. The first 10-week trial evaluated their impact on feeding, fecal physical quality, and the apparent digestibility coefficient(ADC) of dietary nutrients in rainbow trout(initial body weight 18.0 ± 0.2 g). ANC inclusion did not impact the palatability and satiety feed intake of the fish(P > 0.05). However, the ADC of dry matter and phosphorus significantly decreased in fish fed the 20% ANC diet(P < 0.05). The second 9-week trial investigated the growth performance, nutrition quality, and metabolism of rainbow trout(initial body weight 19.0 ± 0.2 g). While all fish exhibited substantial growth, fish fed diets with 10% to20% ANC displayed lower specific growth rate and higher feed conversion ratio compared to those fed with 0% or 5% ANC(P < 0.05). The whole body protein content was higher in fish fed 5% ANC compared to all other treatments(P = 0.030). The biochemical parameters of plasma were similar across treatments,except for a decrease in plasma phosphorus levels in fish fed a 10% ANC diet compared to those fed a 0%ANC diet(P = 0.033). Significant changes were observed in liver metabolism including tricarboxylic acid cycle, amino acid and energy metabolism pathways in fish fed the 20% ANC diet versus the 0% ANC diet(P < 0.05). These results demonstrate that ANC inclusion improved pellet physical quality without impairing feeding behavior and nutritional quality of the fish but inclusion ≥10% in the diet reduced fish growth. This study offers the first comprehensive assessment of the potential of ANC used in fish feed involving feed management, feeding evaluation, and the biological response.
文摘The productivity, product quality and competitive ability of important agricultural and horticultural plants in many regions of the world may be adversely affected by current and anticipated concentrations of ground-level ozone （O_3）. Exposure to elevated O_3 typically results in suppressed photosynthesis, accelerated senescence, decreased growth and lower yields. Various approaches used to evaluate O_3 effects generally concur that current yield losses range from 5% to 15% among sensitive plants. There is, however, considerable genetic variability in plant responses to O_3.
基金support from the National Natural Science Foundation of China(31872871 to QY and U2004207 to MG)the Fund for Distinguished Young Scholars in Henan(212300410007 to MG)+1 种基金the National Key Research and Development Program of China(2020YFA0907900 to QY)the Key Research and Development Program of Shaanxi(2021ZDLNY01-06 to QY)。
文摘In contrast to large-effect qualitative disease resistance,quantitative disease resistance(QDR)exhibits partial and generally durable resistance and has been extensively utilized in crop breeding.The molecular mechanisms underlying QDR remain largely unknown but considerable progress has been made in this area in recent years.In this review,we summarize the genes that have been associated with plant QDR and their biological functions.Many QDR genes belong to the canonical resistance gene categories with predicted functions in pathogen perception,signal transduction,phytohormone homeostasis,metabolite transport and biosynthesis,and epigenetic regulation.However,other"atypical"QDR genes are predicted to be involved in processes that are not commonly associated with disease resistance,such as vesicle trafficking,molecular chaperones,and others.This diversity of function for QDR genes contrasts with qualitative resistance,which is often based on the actions of nucleotidebinding leucine-rich repeat(NLR)resistance proteins.An understanding of the diversity of QDR mechanisms and of which mechanisms are effective against which classes of pathogens will enable the more effective deployment of QDR to produce more durably resistant,resilient crops.
基金supported by Division of Electrical,Communications and Cyber Systems(1809753)National Institute of Food and Agriculture(2020-67021-31961).
文摘Automation of plant phenotyping using data from high-dimensional imaging sensors is on the forefront of agricultural research for its potential to improve seasonal yield by monitoring crop health and accelerating breeding programs.A common challenge when capturing images in the field relates to the spectral reflection of sunlight(glare)from crop leaves that,at certain solar incidences and sensor viewing angles,presents unwanted signals.The research presented here involves the convergence of 2 parallel projects to develop a facile algorithm that can use polarization data to decouple light reflected from the surface of the leaves and light scattered from the leaf's tissue.
文摘Maize is the world＇s most produced crop, providing food, feed, and biofuel. Maize production is constantly threatened by the presence of devastating pathogens worldwide. Characterization of the genetic compo- nents underlying disease resistance is a major research area in maize which is highly relevant for resistance breeding programs. Quantitative disease resistance （QDR） is the type of resistance most widely used by maize breeders. The past decade has witnessed significant progress in fine-mapping and cloning of genes controlling QDR. The molecular mechanisms underlying QDR remain poorly understood and exploited. In this review we discuss recent advances in maize QDR research and strategy for resistance breeding.
基金supported by the National Science Foundation grants IOS-1031416 and IOS-1444456sabbatical leave funding from the Florida Agricultural and Mechanical University
文摘Seed size and composition are important traits in food crops and can be affected by nutrient availability in the soil. Phosphorus （P） is a non-renewable, essential macronutrient, and P deficiency limits soybean （G1ycine max） yield and quality. To investigate the associations of seed traits in low- and high-P environ- ments, soybean recombinant inbred lines （RILs） from a cross of cultivars Fiskeby III and Mandarin （Ottawa） were grown under contrasting P availability environments. Traits including individual seed weight, seed number, and intact mature pod weight were significantly affected by soil P levels and showed transgressive segregation among the RILs. Surprisingly, P treatments did not affect seed composition or weight, suggesting that soybeanmaintains sufficient P in seeds even in Iow-P soil. Quantitative trait loci （QTLs） were detected for seed weight, intact pods, seed volume, and seed protein, with five significant QTLs identified in Iow-P environments and one significant QTL found in the optimaI-P environment. Broad-sense heritability estimates were 0.78 （individual seed weight）, o.go （seed protein）, 0.34 （seed oil）, and 0.98 （seed number）. The QTLs identified under low P point to genetic regions that may be useful to improve soybean performance under limiting P conditions.
文摘Active breeding programs specifically for root system architecture(RSA)phenotypes remain rare;however,breeding for branch and taproot types in the perennial crop alfalfa is ongoing.Phenotyping in this and other crops for active RSA breeding has mostly used visual scoring of specific traits or subjective classification into different root types.While image-based methods have been developed,translation to applied breeding is limited.
基金supported by grants from National Science Foundation(NSF)(award#1444503)National Institute of Food and Agriculture(NIFA)(award#2022-67013-36504).
文摘Plants defend themselves against microbial pathogens in several ways.Among the most important of these mechanisms are cyto-plasmic nucleotide-binding,leucine-rich repeat(NLR)resistance(R)proteins that are activated by direct or indirect interaction with pathogen-derived effector proteins introduced into the plant cell as part of the pathogenesis process.
