Sesame(Sesamum indicum L.)is an ancient diploid oilseed crop valued for its high oil content,quality protein,unsaturated fatty acids,and antioxidants.The emerging research focuses on the utilization of vegetable prote...Sesame(Sesamum indicum L.)is an ancient diploid oilseed crop valued for its high oil content,quality protein,unsaturated fatty acids,and antioxidants.The emerging research focuses on the utilization of vegetable proteins in the development of novel products and the formulation of functional foods.Developing sesame genotypes with higher protein and oil content is a current focus for improving sesame quality traits,as preferred by the sesame seed oil industry and consumers.Despite previous genome-wide association studies(GWAS)on various agronomic and biochemical traits in sesame,the genetic basis of protein content and oil content remains limited.Therefore,this study was designed to identify candidate genes and quantitative trait loci(QTLs)regulating the target traits using 401 sesame accessions grown in three environments(2018WH,2018LQ,and 2022WH).The protein and oil content in the sesame population varied significantly.The protein content ranged from 15.06%to 26.45%,while the oil content was between 41.68%and 60.15%.Furthermore,the white seeds had a higher oil content,while the black seeds had a higher protein content,indicating an association between seed colour and oil and protein content.GWAS results revealed that 632 and 269 QTLs were selected as significant genetic regions for protein and oil content,respectively.Of these significant QTLs,we identified 10 and 22 stable QTLs for protein and oil content,respectively.A total of 17 candidate genes related to protein and oil content were identified within 32 stable quantitative trait loci(QTLs).Interestingly,two variant sites,SNP13:10093594 and In Del13:10935497,related to protein content,were identified in the gene sequences of SINPZ1300586 and SINPZ1300694.Four SNPs,SNP1:22608987,SNP4:13355820,SNP8:21686488,and SNP11:142842,for oil content were found correspond to the genes SINPZ0102106,SINPZ0401222,SINPZ0801731,and SINPZ1100015,respectively.The findings provide light on the genetic basis of protein and oil characteristics.These genes and QTLs can aid the molecular breeding and genetic engineering of innovative sesame germplasm,with improved potential for protein and oil content,as well as desired quality attributes.展开更多
Genomic selection(GS) as a promising molecular breeding strategy has been widely implemented and evaluated for plant breeding, because it has remarkable superiority in enhancing genetic gain, reducing breeding time an...Genomic selection(GS) as a promising molecular breeding strategy has been widely implemented and evaluated for plant breeding, because it has remarkable superiority in enhancing genetic gain, reducing breeding time and expenditure, and accelerating the breeding process. In this study the factors affecting prediction accuracy(rMG) in GS were evaluated systematically, using six agronomic traits(plant height, ear height, ear length, ear diameter,grain yield per plant and hundred-kernel weight) evaluated in one natural and two biparental populations. The factors examined included marker density, population size, heritability,statistical model, population relationships and the ratio of population size between the training and testing sets, the last being revealed by resampling individuals in different proportions from a population. Prediction accuracy continuously increased as marker density and population size increased and was positively correlated with heritability; rMGshowed a slight gain when the training set increased to three times as large as the testing set. Low predictive performance between unrelated populations could be attributed to different allele frequencies, and predictive ability and prediction accuracy could be improved by including more related lines in the training population. Among the seven statistical models examined, including ridge regression best linear unbiased prediction(RR-BLUP), genomic BLUP(GBLUP), Bayes A, Bayes B, Bayes C, Bayesian least absolute shrinkage and selection operator(Bayesian LASSO), and reproducing kernel Hilbert space(RKHS), the RKHS and additive-dominance model(Add + Dom model) showed credible ability for capturing non-additive effects, particularly for complex traits with low heritability. Empirical evidence generated in this study for GS-relevant factors will help plant breeders to develop GS-assisted breeding strategies for more efficient development of varieties.展开更多
Striga hermonthica is a major constraint to smallholder sub-sistence agriculture production in the sub-Saharan African region. Low soil fertility and overall environmental degradation has contributed to the build-up o...Striga hermonthica is a major constraint to smallholder sub-sistence agriculture production in the sub-Saharan African region. Low soil fertility and overall environmental degradation has contributed to the build-up of the parasitic weed infestation. Improved cropping systems have to be introduced to address the interrelated problems of S. her-monthica and soil fertility decline. Thus, the effects of improved fallow with leguminous shrub Sesbania sesban on maize yields and levels of S. hermonthica infestation on farm land in the bimodal highlands of western Kenya were investigated. The experimental treatments were arranged in a phased entry, and randomized complete block scheme were six months Sesbania fallow, 18 months Sesbania fallow, six months natural fallow consisting of regrowth of natural vegetation without cultivation, 18 months natural fallow, continuous maize cropping without fertilizer application, and continuous maize cropping with P and N fertilization. Results show that Sesbania fallows significantly （p0.05） increase maize yield relative to continuous unfertilized maize. S. hermonthica plant populations decrease in continuous maize between the first season （mean = 428 000 ± 63 000 ha-1） and second season （mean=51 000 ± 15 000 ha-1）, presumably in response to good weed management. S. hermonthica seed populations in the soil decrease throughout the duration of the experi-ment in the continuous maize treatments. Short-duration Sesbania fal-lows can provide modest yield improvements relative to continuous unfertilized maize, but short-duration weedy fallows are ineffective. Continuous maize cultivation with good weed control may provide more effective S. hermonthica control than fallowing.展开更多
Wheat rusts continue to cause significant losses worldwide despite major efforts given to their genetic control. This is due to frequent evolution and selection of virulence in pathogen overcoming the deployed race-sp...Wheat rusts continue to cause significant losses worldwide despite major efforts given to their genetic control. This is due to frequent evolution and selection of virulence in pathogen overcoming the deployed race-specific resistance genes. Although the life of effective race-specific resistance genes can be prolonged by using gene combinations, an alternative approach being implemented at CIMMYT is to deploy varieties that posses adult plant resistance （APR） based on combinations of minor, slow rusting genes. When present alone, the APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4 or 5 minor genes usually result in ＂near-immunity＂ or a high level of resistance. Although only a few APR genes are catalogued, various APR QTLs are now known and could lead to further characterization of additional genes. Four characterized genes have pleiotropic effects in conferring partial APR to all 3 rusts and powdery mildew, thus simplifying the task of breeding wheat varieties that are resistant to multiple diseases. Significant progress was made recently in developing high-yielding wheat germplasm that possesses high levels of APR to all three rusts by implementing a Mexico- Kenya shuttle breeding scheme. Parents with APR to Ug99 were hybridized with high-yielding parents that had adequate to high levels of APR to leaf rust and yellow rust. Segregating populations and advanced lines from these crosses were selected under high rust pressures in Mexico （leaf rust and yellow rust） and Kenya （Ug99 stem rust and yellow rust） to identify high- yielding progenies that possess high to adequate APR to all three rusts. International distribution of these high-yielding wheats is underway through CIMMYT intemational yield trials and screening nurseries. It is expected that several wheat varieties with APR to three rusts will be released and grown in various countries in the near-future that will allow determining the durability of resistance.展开更多
This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland ...This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland sites. Linear regression with log transformation was used to model aboveground biomass according to dendrometric parameters. Error analysis, including mean absolute percentage of error(MAPE) and root mean square of error(RMSE), was used to select and validate the models for both species. Model 1(biomass according to tree diameter) for P. africana and F. albida were considered more representative. The statistical parameters of these models were R2 = 0.99, MAPE 0.98% and RMSE1.75% for P. africana, and R2 = 0.99, MAPE 1.19%,RMSE 2.37% for F. albida. The average rate of carbon sequestered was significantly different for the two species(P ≤ 0.05). The total amount sequestered per tree averaged0.17 × 10-3 Mg for P. africana and 0.25 × 10-3 Mg for F. albida. These results could be used to develop policies that would lead to the sustainable management of these resources in the dry parklands of Niger.展开更多
China has the largest area of inland geological phosphorus-rich(GPR) mountains in the world, where vegetation restoration is key to safeguarding the environment. We reviewed the published literature and collected new ...China has the largest area of inland geological phosphorus-rich(GPR) mountains in the world, where vegetation restoration is key to safeguarding the environment. We reviewed the published literature and collected new data in order to analyze re-vegetation patterns and the status of plant communities in central Yunnan. The aim of our analysis was to suggest future improvements to restoration strategies in GPR mountain regions. Our results showed that spontaneous recovery was the most widespread type of restoration. N-fixing species such as Coriaria nepalensis and Alnus nepalensis play a vital role in succession. In the past, monoculture tree plantation was the primary method used in afforestation activities in central Yunnan; in recent years however, several different methods of restoration have been introduced including the use of agroforestry systems. For practical restoration, we found that spontaneous recovery was capable of delivering the best results, but that during its early stages, restoration results were affected by several factors including erosion risk, the origin of propagates and environmental variation. In contrast, methods employing human-made communities performed better in their early stages, but were constrained by higher costs and vulnerability to degradation and erosion. The use of N-fixing species such as A. nepalensis and Acacia mearnsii in plantations were unsuccessful in restoring full ecosystem functions. The success of restoration activities in GPR mountain regions could be improved through the following measures:(1) developing a better understanding of the respective advantages and disadvantages of current natural and human-engineered restoration approaches;(2) elucidating the feedback mechanism between phosphorus-rich soil and species selected for restoration, especially N-fixing species;(3) introducing market incentives aimed at encouraging specific restoration activities such as agroforestry, and improving the industry value chain.展开更多
Amid the euphoria of Reducing Emissions from Deforestation and Forest Degradation (REDD) and REDD+ discussions, the expectations of large financial gains raise the interest of all. A country, however, will only enjoy ...Amid the euphoria of Reducing Emissions from Deforestation and Forest Degradation (REDD) and REDD+ discussions, the expectations of large financial gains raise the interest of all. A country, however, will only enjoy REDD benefits if the cost of REDD is lower than the benefit. The opportunity cost analysis is an effective tool for assessing the feasibility of REDD+ since the largest portion of costs associated with REDD+ and can help to identify fair compensation for those who change their land use. The opportunity cost analysis has been exercised in Tanjung Jabung Barat (Tanjabar) district-Indonesia to examine the economic-feasibility of carbon emission reduction under different type carbon price scenarios. This study reveals a sharp decline of land-use systems with high carbon-stock and low profitability is obvious. On mineral soil, low carbon-stock and high profitability (mostly oil palm) has increased rapidly, especially in the period 2000-2009. It has become the dominant land-use system. The low-to-medium carbon stock and medium profitability land-use category increased from 1990 to 2005 but declined from 2005 to 2009. The low carbon-stock and low profitability category was constant and the proportion of the area was below 15%. The ex-ante analysis in predicting the potential for future emissions reduction in Tanjabar through REDD+ approaches shows that the cumulative emission of Tanjabar in 2020 is estimated at 61.91 Mg CO2-eq/Ha.Year, while the reduced emission by excluding all land use conversion below $5 threshold is estimated at 51.71 Mg CO2-eq/Ha.Year. This means that there is a potential for 16% emission reduction using $5/ton CO2-eq incentive. Another important finding in this study is that if the price of carbon increases by double to $10, the amount of reduced emission does not change much. This can use as a basis for determining the right amount of incentive for trade-off between economic profitability and climate change mitigation effort in Tanjabar using REDD+ scheme both at seller and buyer perspectives.展开更多
The purpose of the research was to compare the profitability of existing land uses in Tanjung Jabung Barat, Jambi province, Indonesia, for formulating a strategy to reduce emissions from deforestation and de-gradation...The purpose of the research was to compare the profitability of existing land uses in Tanjung Jabung Barat, Jambi province, Indonesia, for formulating a strategy to reduce emissions from deforestation and de-gradation (REDD). Net Present Value was used for comparing profits of different types of investment (e.g. different type of land use). Rapid Rural Appraisal was used to gather information on farm budget data for each land use, including prices, production, labor and other input. The results of the profitability analysis showed that all land uses, both on mineral soil and peat land, were profitable. Oil palm, both in large plantations and smallholder gardens, was the most profitable land-use system. However, the profitability of smallholder oil palm on peatland was lower than on mineral soils yet oil palm was still more competitive than rubber on mineral soils. The competitiveness of mixed gardens with oil palm was higher on peatland and the threat of converting other land uses to oil palm was higher on mineral soil than on peat. For crop systems, irrigated paddy had the highest profitability.展开更多
Background: There is increasing research interest in using short-chain fatty acids(SCFAs) including butyrate as potential alternatives to antibiotic growth promoters in animal production. This study was conducted to e...Background: There is increasing research interest in using short-chain fatty acids(SCFAs) including butyrate as potential alternatives to antibiotic growth promoters in animal production. This study was conducted to evaluate the effects of supplementation of sodium butyrate(SB) in liquid feeds(milk, milk replacer, and the mixture of both)on the growth performance, rumen fermentation, and serum antioxidant capacity and immunoglobins in dairy calves before weaning. Forty healthy female Holstein calves(4-day-old, 40 ± 5 kg of body weight) were housed in individual hutches and randomly allocated to 1 of 4 treatment groups(n = 10 per group) using the RAND function in Excel. The control group was fed no SB(SB0), while the other three groups were supplemented with 15(SB15),30(SB30), or 45(SB45) g/d of SB mixed into liquid feeds offered. The calves were initially fed milk only(days 2 to 20), then a mixture of milk and milk replacer(days 21 to 23), and finally milk replacer only(days 24 to 60).Results: The SB supplementation enhanced growth and improved feed conversion into body weight gain compared with the SB0 group, and the average daily gain increased quadratically with increasing SB supplementation. No significant effect on rumen pH;concentrations of NH_3-N, individual and total VFAs;or acetate:propionate(A:P) ratio was found during the whole experimental period. Serum glutathione peroxidase activity increased linearly with the increased SB supplementation, while the serum concentration of maleic dialdehyde linearly decreased. Serum concentrations of immunoglobulin A, immunoglobulin G, or immunoglobulin M were not affected by the SB supplementation during the whole experimental period.Conclusions: Under the conditions of this study, SB supplementation improved growth performance and antioxidant function in pre-weaned dairy calves. We recommended 45 g/d as the optimal level of SB supplementation mixed into liquid feeds(milk or milk replacer) to improve the growth and antioxidant function of dairy calves before weaning.展开更多
Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in Central Western Ghats, India one of the eight top hotspots of b...Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in Central Western Ghats, India one of the eight top hotspots of biodiversity in the world. We combined biodiversity inven-tory of trees with village interviews to record traditional ecological knowledge. Wild edible fruits were an opportunistic source of food for rural people. Wild edible fruits were rich in minerals, vitamins, carbohy-drates, proteins, fats and fiber. In recent years there has been a decline in numbers of wild fruit trees due to changes in land use from uncultivated private wooded area to cardamom and coffee cultivation. The availability of wild edible fruits that were once very common on private cultivated areas has declined and their distributions are now restricted more to jungles and wildlife sanctuaries. We propose methods for conservation and describe the need for sustainable utilization to provide supplemen-tary sources of nutritional and pharmaceutically useful edible wild fruits.展开更多
A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associ...A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic,as alternative to tree planting.Tree diversity in secondary forests may be high,but based on newcomer species of low wood density and long-distance,abiotic dispersal modes.We compiled and analyzed three pairs of case studies(totaling 815 plots and 11.8 ha)of secondary forests recovering from logging,fire and conversion to agroforest in Sumatra and Kalimantan(Indonesia)on mineral soils.Data on tree species diversity,wood density frequency distribution(indicative of successional status)and dispersal modes were compared with those of less disturbed comparator forests in the same landscapes.Relatively undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees(>10 cm diameter)at a 1-ha sample scale(and 450 at a 10-ha scale).After repeated fires a sample area of 2 ha was needed to reach the same species richness.Regulation-based logging had little impact on tree species richness.In rubber agroforest with low-intensity management beyond rubber planting,50 tree species were found at a 1-ha scale and close to 100 species in 3 ha.The Kalimantan forest after repeated fires had a markedly higher fraction of lowwood-density trees(40%),but otherwise,all forests sampled were similar in overall wood density profiles.Selectively logged forest managed by a local community(village forest)and rubber agroforest in Sumatra contained larger fractions of heavy-wood-density trees.The majority of trees(50%–70%)had birds,bats and primates as dispersal agents in all sites.Selectively logged forests had higher fractions of autochorous species(15%)compared to other sites.Anemochorous(wind-dispersed)species,especially Macaranga lowii,were most common(20%)in lowland dipterocarp forest.Comparison between secondary forests and agroforests showed the influence of farmer selection regarding what is allowed to grow beyond the pole stage.Wood density and seed dispersal profiles can be used as degradation indicators of species assemblages across various disturbance levels and types,as they reflect the habitat quality of the surrounding landscape mosaics.展开更多
Vegetative propagation by stem cutting is an important technique applied for agricultural production where rooting success is one of the major aspects. A study to assess the effects of mode of application of rooting h...Vegetative propagation by stem cutting is an important technique applied for agricultural production where rooting success is one of the major aspects. A study to assess the effects of mode of application of rooting hormones (IBA) on adventitious root formation of V. paradoxa stem cuttings was conducted. Accordingly, four application methods were investigated in a 4 × 3 factorial experiment using a Completely Randomized Design (CRD). The application methods were: 24-hour extended soak, foliar spraying, basal quick dip and delayed IBA application method. Thus, the parameters used to determine rooting success were mean root length and root number. The effect of these application methods on occurrence of bud break was also considered. On the whole, root length was observed to be a function of IBA concentration, whereby root length increased significantly (P ≤ 0.05) with an increment in IBA concentration. Stem cuttings subjected to 24-h extended soak at 100 ppm rooted best (59.5% ± 8.33%), where as foliar sprayed stem cuttings exhibited the worst rooting success (11.9 ± 3.06 - 23.8% ± 4.16%). Bud break appeared to decrease with increasing IBA concentration and delaying IBA application enhanced rooting percentage of the quick dip method by 7.1%, 9.5% and 11.9% at 2500 ppm, 3500 ppm and 4500 ppm, respectively. The extended soak method of IBA application at 80 ppm shows potential for large scale production of V. paradoxa through stem cuttings.展开更多
A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical c...A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical characteristics, yield components and late blight disease severity of potato （Solanum tuberosum）. A two factorial treatment combination made up of fertilization schemes and sanitary measures were laid out in a randomized complete block design （RCBD） with four replicates and 10 treatments. Data collected were subjected to a multivariate ANOVA and means separated with the Dunnett t-test with Calliandra calothyrsus considered as the main treatment. Mineral fertilizers and Calliandra calothyrsus significantly augmented stem diameter, plant height and plant vigor, total and marketable yields, despite the fact that late blight severity was high in the two treatments. The correlation matrix showed that total yield had significant and positive correlation with stem diameter （r = 0.74）, plant height （r = 0.61）, plant vigor （r = 0.61） and marketable yield （r = 0.99） and negative correlation （r = -37） with late blight severity. The increase observed is attributed to the nutrient contents of the treatments applied. Leafy prunings of C. calothyrsus increase soil organic matter which probably improves moisture retention and biological activity. The highest late blight severity recorded between the 45 and 60 coincides with active development of plant canopy which influences disease severity and create a canopy microclimate conducive to disease development. This study suggests that Calliandra calothyrsus has the potential of improving potato production provided appropriate fungicide is used.展开更多
The leaf phenology of trees has received particular attention for its crucial role in the global water and carbon balances,ecosystem,and species distribution.However,current studies on leaf phenology have mainly focus...The leaf phenology of trees has received particular attention for its crucial role in the global water and carbon balances,ecosystem,and species distribution.However,current studies on leaf phenology have mainly focused on temperate trees,while few studies including tropical trees.Little attention has been paid to globally extensive industrial plantations.Rubber plantations are important to both the local and global economies.In this study,we investigated the legacy effects of defoliation phenology on the following year’s leaf flushing,leaf disease,and also latex yield of rubber trees,an economically important tree to local people and the world.Results show that extended duration of defoliation increased the subsequent duration of refoliation and rates of infection by powdery mildew disease,but led to reduced latex yield in March.This legacy effect of rubber defoliation may relate to the carbohydrate reserved in the trees.A longer duration of defoliation would consume more reserved carbohydrates,reducing available reserves for disease defense and latex production.Extended duration of defoliation period was associated with either a lower temperature before the cessation of latex tapping in October-November and/or a higher temperature after the cessation of latex tapping in December-January.Leaf falling signals the end of photosynthetic activities in deciduous trees.Thus,the leaf falling phenology will impact ecological processes involving rubber trees.Our findings indicated that the inclusion of defoliation periods in future rubber trees’ research,will be crucial to furthering our understanding of leaf flushing,powdery mildew disease,and latex yield.展开更多
基金funded by the National Key Research and Development Program of China(2024YFD1600100)the Agricultural Science and Technology Innovation Program of the Chinese Academy of Agricultural Sciences(CAAS-ASTIP-2021-OCRI)+3 种基金China Agriculture Research System(CARS-14)Hubei International Science and Technology Cooperation Project(2024EHA055)Science and Technology Innovation Project of Hubei province(2024-620-000-001-031)Fundamental Research Funds for Central Non-profit Scientific Institution(1610172023003)。
文摘Sesame(Sesamum indicum L.)is an ancient diploid oilseed crop valued for its high oil content,quality protein,unsaturated fatty acids,and antioxidants.The emerging research focuses on the utilization of vegetable proteins in the development of novel products and the formulation of functional foods.Developing sesame genotypes with higher protein and oil content is a current focus for improving sesame quality traits,as preferred by the sesame seed oil industry and consumers.Despite previous genome-wide association studies(GWAS)on various agronomic and biochemical traits in sesame,the genetic basis of protein content and oil content remains limited.Therefore,this study was designed to identify candidate genes and quantitative trait loci(QTLs)regulating the target traits using 401 sesame accessions grown in three environments(2018WH,2018LQ,and 2022WH).The protein and oil content in the sesame population varied significantly.The protein content ranged from 15.06%to 26.45%,while the oil content was between 41.68%and 60.15%.Furthermore,the white seeds had a higher oil content,while the black seeds had a higher protein content,indicating an association between seed colour and oil and protein content.GWAS results revealed that 632 and 269 QTLs were selected as significant genetic regions for protein and oil content,respectively.Of these significant QTLs,we identified 10 and 22 stable QTLs for protein and oil content,respectively.A total of 17 candidate genes related to protein and oil content were identified within 32 stable quantitative trait loci(QTLs).Interestingly,two variant sites,SNP13:10093594 and In Del13:10935497,related to protein content,were identified in the gene sequences of SINPZ1300586 and SINPZ1300694.Four SNPs,SNP1:22608987,SNP4:13355820,SNP8:21686488,and SNP11:142842,for oil content were found correspond to the genes SINPZ0102106,SINPZ0401222,SINPZ0801731,and SINPZ1100015,respectively.The findings provide light on the genetic basis of protein and oil characteristics.These genes and QTLs can aid the molecular breeding and genetic engineering of innovative sesame germplasm,with improved potential for protein and oil content,as well as desired quality attributes.
基金supported by the National Basic Research Program of China(2014 CB138206)National Key Research and Development Program of China(2016YFD0101803)+3 种基金the National Natural Science Foundation of China-CGIAR International Collaborative Program(31361140364)the Agricultural Science and Technology Innovation Program(ASTIP)of CAASFundamental Research Funds for Central Non-Profit of Institute of Crop Sciences,CAAS(1610092016124)supported by the Bill and Melinda Gates Foundation and the CGIAR Research Program MAIZE
文摘Genomic selection(GS) as a promising molecular breeding strategy has been widely implemented and evaluated for plant breeding, because it has remarkable superiority in enhancing genetic gain, reducing breeding time and expenditure, and accelerating the breeding process. In this study the factors affecting prediction accuracy(rMG) in GS were evaluated systematically, using six agronomic traits(plant height, ear height, ear length, ear diameter,grain yield per plant and hundred-kernel weight) evaluated in one natural and two biparental populations. The factors examined included marker density, population size, heritability,statistical model, population relationships and the ratio of population size between the training and testing sets, the last being revealed by resampling individuals in different proportions from a population. Prediction accuracy continuously increased as marker density and population size increased and was positively correlated with heritability; rMGshowed a slight gain when the training set increased to three times as large as the testing set. Low predictive performance between unrelated populations could be attributed to different allele frequencies, and predictive ability and prediction accuracy could be improved by including more related lines in the training population. Among the seven statistical models examined, including ridge regression best linear unbiased prediction(RR-BLUP), genomic BLUP(GBLUP), Bayes A, Bayes B, Bayes C, Bayesian least absolute shrinkage and selection operator(Bayesian LASSO), and reproducing kernel Hilbert space(RKHS), the RKHS and additive-dominance model(Add + Dom model) showed credible ability for capturing non-additive effects, particularly for complex traits with low heritability. Empirical evidence generated in this study for GS-relevant factors will help plant breeders to develop GS-assisted breeding strategies for more efficient development of varieties.
基金supported by Swedish International Development Cooperation Agency (Sida)
文摘Striga hermonthica is a major constraint to smallholder sub-sistence agriculture production in the sub-Saharan African region. Low soil fertility and overall environmental degradation has contributed to the build-up of the parasitic weed infestation. Improved cropping systems have to be introduced to address the interrelated problems of S. her-monthica and soil fertility decline. Thus, the effects of improved fallow with leguminous shrub Sesbania sesban on maize yields and levels of S. hermonthica infestation on farm land in the bimodal highlands of western Kenya were investigated. The experimental treatments were arranged in a phased entry, and randomized complete block scheme were six months Sesbania fallow, 18 months Sesbania fallow, six months natural fallow consisting of regrowth of natural vegetation without cultivation, 18 months natural fallow, continuous maize cropping without fertilizer application, and continuous maize cropping with P and N fertilization. Results show that Sesbania fallows significantly （p0.05） increase maize yield relative to continuous unfertilized maize. S. hermonthica plant populations decrease in continuous maize between the first season （mean = 428 000 ± 63 000 ha-1） and second season （mean=51 000 ± 15 000 ha-1）, presumably in response to good weed management. S. hermonthica seed populations in the soil decrease throughout the duration of the experi-ment in the continuous maize treatments. Short-duration Sesbania fal-lows can provide modest yield improvements relative to continuous unfertilized maize, but short-duration weedy fallows are ineffective. Continuous maize cultivation with good weed control may provide more effective S. hermonthica control than fallowing.
基金financial resources from the Durable Rust Resistant Wheat Project led by Cornell University,USAsupported by the Bill & Melinda Gates Foundation+6 种基金ICAR-IndiaUSDA-ARS and USAID,USAGRDC AustraliaAgrovegetal-Spainthe Northwestern Mexican Farmer Association (Patronato) and CONFUPRO,MexicoSDC,SwitzerlandCIMMYT and INIFAP
文摘Wheat rusts continue to cause significant losses worldwide despite major efforts given to their genetic control. This is due to frequent evolution and selection of virulence in pathogen overcoming the deployed race-specific resistance genes. Although the life of effective race-specific resistance genes can be prolonged by using gene combinations, an alternative approach being implemented at CIMMYT is to deploy varieties that posses adult plant resistance （APR） based on combinations of minor, slow rusting genes. When present alone, the APR genes do not confer adequate resistance especially under high disease pressure; however, combinations of 4 or 5 minor genes usually result in ＂near-immunity＂ or a high level of resistance. Although only a few APR genes are catalogued, various APR QTLs are now known and could lead to further characterization of additional genes. Four characterized genes have pleiotropic effects in conferring partial APR to all 3 rusts and powdery mildew, thus simplifying the task of breeding wheat varieties that are resistant to multiple diseases. Significant progress was made recently in developing high-yielding wheat germplasm that possesses high levels of APR to all three rusts by implementing a Mexico- Kenya shuttle breeding scheme. Parents with APR to Ug99 were hybridized with high-yielding parents that had adequate to high levels of APR to leaf rust and yellow rust. Segregating populations and advanced lines from these crosses were selected under high rust pressures in Mexico （leaf rust and yellow rust） and Kenya （Ug99 stem rust and yellow rust） to identify high- yielding progenies that possess high to adequate APR to all three rusts. International distribution of these high-yielding wheats is underway through CIMMYT intemational yield trials and screening nurseries. It is expected that several wheat varieties with APR to three rusts will be released and grown in various countries in the near-future that will allow determining the durability of resistance.
基金supported by the project stocks and potential of carbon sequestration under agroforestry parklands in Niger funded by African Forest Forum(AFF)and International Foundation for Science(IFS),Grant No.D/563-1
文摘This study developed allometric models to estimate aboveground biomass and carbon of Prosopis africana and Faidherbia albida. The destructive method was used with a sample of 20 trees per species for the two parkland sites. Linear regression with log transformation was used to model aboveground biomass according to dendrometric parameters. Error analysis, including mean absolute percentage of error(MAPE) and root mean square of error(RMSE), was used to select and validate the models for both species. Model 1(biomass according to tree diameter) for P. africana and F. albida were considered more representative. The statistical parameters of these models were R2 = 0.99, MAPE 0.98% and RMSE1.75% for P. africana, and R2 = 0.99, MAPE 1.19%,RMSE 2.37% for F. albida. The average rate of carbon sequestered was significantly different for the two species(P ≤ 0.05). The total amount sequestered per tree averaged0.17 × 10-3 Mg for P. africana and 0.25 × 10-3 Mg for F. albida. These results could be used to develop policies that would lead to the sustainable management of these resources in the dry parklands of Niger.
基金the support of the Chinese Academy of Sciences' Frontier Science Key Project (QYZDY-SSWSMC014)The Federal Ministry for Economic Cooperation and Development, Germany(#13.1432.7-001.00)Project funded by Yunnan Postdoctoral Science Foundation (Y732081261)
文摘China has the largest area of inland geological phosphorus-rich(GPR) mountains in the world, where vegetation restoration is key to safeguarding the environment. We reviewed the published literature and collected new data in order to analyze re-vegetation patterns and the status of plant communities in central Yunnan. The aim of our analysis was to suggest future improvements to restoration strategies in GPR mountain regions. Our results showed that spontaneous recovery was the most widespread type of restoration. N-fixing species such as Coriaria nepalensis and Alnus nepalensis play a vital role in succession. In the past, monoculture tree plantation was the primary method used in afforestation activities in central Yunnan; in recent years however, several different methods of restoration have been introduced including the use of agroforestry systems. For practical restoration, we found that spontaneous recovery was capable of delivering the best results, but that during its early stages, restoration results were affected by several factors including erosion risk, the origin of propagates and environmental variation. In contrast, methods employing human-made communities performed better in their early stages, but were constrained by higher costs and vulnerability to degradation and erosion. The use of N-fixing species such as A. nepalensis and Acacia mearnsii in plantations were unsuccessful in restoring full ecosystem functions. The success of restoration activities in GPR mountain regions could be improved through the following measures:(1) developing a better understanding of the respective advantages and disadvantages of current natural and human-engineered restoration approaches;(2) elucidating the feedback mechanism between phosphorus-rich soil and species selected for restoration, especially N-fixing species;(3) introducing market incentives aimed at encouraging specific restoration activities such as agroforestry, and improving the industry value chain.
文摘Amid the euphoria of Reducing Emissions from Deforestation and Forest Degradation (REDD) and REDD+ discussions, the expectations of large financial gains raise the interest of all. A country, however, will only enjoy REDD benefits if the cost of REDD is lower than the benefit. The opportunity cost analysis is an effective tool for assessing the feasibility of REDD+ since the largest portion of costs associated with REDD+ and can help to identify fair compensation for those who change their land use. The opportunity cost analysis has been exercised in Tanjung Jabung Barat (Tanjabar) district-Indonesia to examine the economic-feasibility of carbon emission reduction under different type carbon price scenarios. This study reveals a sharp decline of land-use systems with high carbon-stock and low profitability is obvious. On mineral soil, low carbon-stock and high profitability (mostly oil palm) has increased rapidly, especially in the period 2000-2009. It has become the dominant land-use system. The low-to-medium carbon stock and medium profitability land-use category increased from 1990 to 2005 but declined from 2005 to 2009. The low carbon-stock and low profitability category was constant and the proportion of the area was below 15%. The ex-ante analysis in predicting the potential for future emissions reduction in Tanjabar through REDD+ approaches shows that the cumulative emission of Tanjabar in 2020 is estimated at 61.91 Mg CO2-eq/Ha.Year, while the reduced emission by excluding all land use conversion below $5 threshold is estimated at 51.71 Mg CO2-eq/Ha.Year. This means that there is a potential for 16% emission reduction using $5/ton CO2-eq incentive. Another important finding in this study is that if the price of carbon increases by double to $10, the amount of reduced emission does not change much. This can use as a basis for determining the right amount of incentive for trade-off between economic profitability and climate change mitigation effort in Tanjabar using REDD+ scheme both at seller and buyer perspectives.
文摘The purpose of the research was to compare the profitability of existing land uses in Tanjung Jabung Barat, Jambi province, Indonesia, for formulating a strategy to reduce emissions from deforestation and de-gradation (REDD). Net Present Value was used for comparing profits of different types of investment (e.g. different type of land use). Rapid Rural Appraisal was used to gather information on farm budget data for each land use, including prices, production, labor and other input. The results of the profitability analysis showed that all land uses, both on mineral soil and peat land, were profitable. Oil palm, both in large plantations and smallholder gardens, was the most profitable land-use system. However, the profitability of smallholder oil palm on peatland was lower than on mineral soils yet oil palm was still more competitive than rubber on mineral soils. The competitiveness of mixed gardens with oil palm was higher on peatland and the threat of converting other land uses to oil palm was higher on mineral soil than on peat. For crop systems, irrigated paddy had the highest profitability.
基金partially supported by the National Natural Science Foundation of China (award number:31802092)the National Key Research and Development Program of China (award numbers:2018YFE0101400 and 2017YFD0500502)+1 种基金the Agriculture Science and Technology Innovation Program (award number:ASTIP-IAS07-1)Beijing Dairy Industry Innovation Team (award number:BAIC06–2020)。
文摘Background: There is increasing research interest in using short-chain fatty acids(SCFAs) including butyrate as potential alternatives to antibiotic growth promoters in animal production. This study was conducted to evaluate the effects of supplementation of sodium butyrate(SB) in liquid feeds(milk, milk replacer, and the mixture of both)on the growth performance, rumen fermentation, and serum antioxidant capacity and immunoglobins in dairy calves before weaning. Forty healthy female Holstein calves(4-day-old, 40 ± 5 kg of body weight) were housed in individual hutches and randomly allocated to 1 of 4 treatment groups(n = 10 per group) using the RAND function in Excel. The control group was fed no SB(SB0), while the other three groups were supplemented with 15(SB15),30(SB30), or 45(SB45) g/d of SB mixed into liquid feeds offered. The calves were initially fed milk only(days 2 to 20), then a mixture of milk and milk replacer(days 21 to 23), and finally milk replacer only(days 24 to 60).Results: The SB supplementation enhanced growth and improved feed conversion into body weight gain compared with the SB0 group, and the average daily gain increased quadratically with increasing SB supplementation. No significant effect on rumen pH;concentrations of NH_3-N, individual and total VFAs;or acetate:propionate(A:P) ratio was found during the whole experimental period. Serum glutathione peroxidase activity increased linearly with the increased SB supplementation, while the serum concentration of maleic dialdehyde linearly decreased. Serum concentrations of immunoglobulin A, immunoglobulin G, or immunoglobulin M were not affected by the SB supplementation during the whole experimental period.Conclusions: Under the conditions of this study, SB supplementation improved growth performance and antioxidant function in pre-weaned dairy calves. We recommended 45 g/d as the optimal level of SB supplementation mixed into liquid feeds(milk or milk replacer) to improve the growth and antioxidant function of dairy calves before weaning.
文摘Forty-five species of wild edible fruits were identified and traditional local knowledge of their usage was recorded in 40 villages of Kodagu district in Central Western Ghats, India one of the eight top hotspots of biodiversity in the world. We combined biodiversity inven-tory of trees with village interviews to record traditional ecological knowledge. Wild edible fruits were an opportunistic source of food for rural people. Wild edible fruits were rich in minerals, vitamins, carbohy-drates, proteins, fats and fiber. In recent years there has been a decline in numbers of wild fruit trees due to changes in land use from uncultivated private wooded area to cardamom and coffee cultivation. The availability of wild edible fruits that were once very common on private cultivated areas has declined and their distributions are now restricted more to jungles and wildlife sanctuaries. We propose methods for conservation and describe the need for sustainable utilization to provide supplemen-tary sources of nutritional and pharmaceutically useful edible wild fruits.
基金Earlier data collection and current data analysis were part of the CGIAR program on Forests,Trees and Agroforestry (FTA)
文摘A main question in restoration of degraded forests and forest landscapes recovering from logging and fire is what to expect from natural regeneration through surviving propagules in the soil or seed sources and associated dispersal agents from the surrounding landscape mosaic,as alternative to tree planting.Tree diversity in secondary forests may be high,but based on newcomer species of low wood density and long-distance,abiotic dispersal modes.We compiled and analyzed three pairs of case studies(totaling 815 plots and 11.8 ha)of secondary forests recovering from logging,fire and conversion to agroforest in Sumatra and Kalimantan(Indonesia)on mineral soils.Data on tree species diversity,wood density frequency distribution(indicative of successional status)and dispersal modes were compared with those of less disturbed comparator forests in the same landscapes.Relatively undisturbed lowland dipterocarp forest in Kalimantan had close to 200 species of trees(>10 cm diameter)at a 1-ha sample scale(and 450 at a 10-ha scale).After repeated fires a sample area of 2 ha was needed to reach the same species richness.Regulation-based logging had little impact on tree species richness.In rubber agroforest with low-intensity management beyond rubber planting,50 tree species were found at a 1-ha scale and close to 100 species in 3 ha.The Kalimantan forest after repeated fires had a markedly higher fraction of lowwood-density trees(40%),but otherwise,all forests sampled were similar in overall wood density profiles.Selectively logged forest managed by a local community(village forest)and rubber agroforest in Sumatra contained larger fractions of heavy-wood-density trees.The majority of trees(50%–70%)had birds,bats and primates as dispersal agents in all sites.Selectively logged forests had higher fractions of autochorous species(15%)compared to other sites.Anemochorous(wind-dispersed)species,especially Macaranga lowii,were most common(20%)in lowland dipterocarp forest.Comparison between secondary forests and agroforests showed the influence of farmer selection regarding what is allowed to grow beyond the pole stage.Wood density and seed dispersal profiles can be used as degradation indicators of species assemblages across various disturbance levels and types,as they reflect the habitat quality of the surrounding landscape mosaics.
文摘Vegetative propagation by stem cutting is an important technique applied for agricultural production where rooting success is one of the major aspects. A study to assess the effects of mode of application of rooting hormones (IBA) on adventitious root formation of V. paradoxa stem cuttings was conducted. Accordingly, four application methods were investigated in a 4 × 3 factorial experiment using a Completely Randomized Design (CRD). The application methods were: 24-hour extended soak, foliar spraying, basal quick dip and delayed IBA application method. Thus, the parameters used to determine rooting success were mean root length and root number. The effect of these application methods on occurrence of bud break was also considered. On the whole, root length was observed to be a function of IBA concentration, whereby root length increased significantly (P ≤ 0.05) with an increment in IBA concentration. Stem cuttings subjected to 24-h extended soak at 100 ppm rooted best (59.5% ± 8.33%), where as foliar sprayed stem cuttings exhibited the worst rooting success (11.9 ± 3.06 - 23.8% ± 4.16%). Bud break appeared to decrease with increasing IBA concentration and delaying IBA application enhanced rooting percentage of the quick dip method by 7.1%, 9.5% and 11.9% at 2500 ppm, 3500 ppm and 4500 ppm, respectively. The extended soak method of IBA application at 80 ppm shows potential for large scale production of V. paradoxa through stem cuttings.
文摘A field experiment was conducted in the Western Highlands of Cameroon to study the effects of Calliandra calothyrsus, sterilized compost, non-sterilized compost and mineral fertilizers （NPK 11：11：22） on physical characteristics, yield components and late blight disease severity of potato （Solanum tuberosum）. A two factorial treatment combination made up of fertilization schemes and sanitary measures were laid out in a randomized complete block design （RCBD） with four replicates and 10 treatments. Data collected were subjected to a multivariate ANOVA and means separated with the Dunnett t-test with Calliandra calothyrsus considered as the main treatment. Mineral fertilizers and Calliandra calothyrsus significantly augmented stem diameter, plant height and plant vigor, total and marketable yields, despite the fact that late blight severity was high in the two treatments. The correlation matrix showed that total yield had significant and positive correlation with stem diameter （r = 0.74）, plant height （r = 0.61）, plant vigor （r = 0.61） and marketable yield （r = 0.99） and negative correlation （r = -37） with late blight severity. The increase observed is attributed to the nutrient contents of the treatments applied. Leafy prunings of C. calothyrsus increase soil organic matter which probably improves moisture retention and biological activity. The highest late blight severity recorded between the 45 and 60 coincides with active development of plant canopy which influences disease severity and create a canopy microclimate conducive to disease development. This study suggests that Calliandra calothyrsus has the potential of improving potato production provided appropriate fungicide is used.
基金financially supported by the Key Research Program of Frontier Sciences,the Chinese Academy of Sciences (No.QYZDY-SSW-SMC014)the National Natural Science Foundation of China (No.32171576)。
文摘The leaf phenology of trees has received particular attention for its crucial role in the global water and carbon balances,ecosystem,and species distribution.However,current studies on leaf phenology have mainly focused on temperate trees,while few studies including tropical trees.Little attention has been paid to globally extensive industrial plantations.Rubber plantations are important to both the local and global economies.In this study,we investigated the legacy effects of defoliation phenology on the following year’s leaf flushing,leaf disease,and also latex yield of rubber trees,an economically important tree to local people and the world.Results show that extended duration of defoliation increased the subsequent duration of refoliation and rates of infection by powdery mildew disease,but led to reduced latex yield in March.This legacy effect of rubber defoliation may relate to the carbohydrate reserved in the trees.A longer duration of defoliation would consume more reserved carbohydrates,reducing available reserves for disease defense and latex production.Extended duration of defoliation period was associated with either a lower temperature before the cessation of latex tapping in October-November and/or a higher temperature after the cessation of latex tapping in December-January.Leaf falling signals the end of photosynthetic activities in deciduous trees.Thus,the leaf falling phenology will impact ecological processes involving rubber trees.Our findings indicated that the inclusion of defoliation periods in future rubber trees’ research,will be crucial to furthering our understanding of leaf flushing,powdery mildew disease,and latex yield.
