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1.
There are several hurdles to ensure sustainable seed production and consistent flow of improved legume varieties in sub‐Saharan Africa (SSA) and South Asia (SA). The unreliable demand, autogamous nature of most of the grain legumes, and slow variety replacement rate by smallholder farmers do not provide strong incentive for private seed companies to invest in legume seed business. Unless a well thought‐out and comprehensive approach to legume seed delivery is developed, current seed shortages will continue, eroding emerging market opportunities. The experiences reported here are collated through a 10‐year partnership project, the Tropical Legumes in SSA and SA. It fostered innovative public–private partnerships in joint testing of innovative market‐led seed systems, skills and knowledge enhancement, de‐risking private sector initiatives that introduced in new approaches and previously overlooked entities in technology delivery. As new public and private seed companies, individual seed entrepreneurs and farmer organizations emerged, the existing ones enhanced their capacities. This resulted in significant rise in production, availability and accessibility of various seed grades of newly improved and farmer demanded legume varieties in the target countries.  相似文献   

2.
Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.  相似文献   

3.
Genomic selection (GS) is a powerful method for exploitation of DNA sequence polymorphisms in breeding improvement, through the prediction of breeding values based on all markers distributed genome‐wide. Forage grasses and legumes provide important targets for GS implementation, as many key traits are difficult or expensive to assess, and are measured late in the breeding cycle. Generic attributes of forage breeding programmes are described, along with status of genomic resources for a representative species group (ryegrasses). Two schemes for implementing GS in ryegrass breeding are described. The first requires relatively little modification of current schemes, but could lead to significant reductions in operating cost. The second scheme would allow two rounds of selection for key agronomic traits within a time period previously required for a single round, potentially leading to doubling of genetic gain rate, but requires a purpose‐designed reference population. In both schemes, the limited extent of linkage disequilibrium (LD), which is the major challenge for GS implementation in ryegrass breeding, is addressed. The strategies also incorporate recent advances in DNA sequencing technology to minimize costs.  相似文献   

4.
Grain legumes being affordable sources of proteins, vitamins and essential micronutrients are key to human nutrition worldwide. However, frequent drought episodes present serious threat to grain legume production worldwide. Advances in legume omics in concert with evolving phenotyping and breeding techniques hold great promise to improve drought response of these crops. These resources could underpin prebreeding efforts to expedite discovery and deployment of novel drought tolerance traits into elite backgrounds. Fast-track transfer of traits that confer drought tolerance using marker technologies has been demonstrated in grain legumes like chickpea. However, complex genetic architecture of drought tolerance demands embracing more efficient tools like genomic selection (GS) for accelerated trait improvement. Recent studies on GS for addressing complex traits like drought tolerance have yielded encouraging results in these crops. Recently, speed breeding (SB) protocols have also been optimized for the improvement of long-day/day-neutral grain legumes. Efficacy of SB protocols with regard to complex traits awaits further evidences though. There remains immense scope for integrating SB with GS and gene editing to deliver drought-tolerant cultivars.  相似文献   

5.
This article highlights 12 years (2007–2019) of research, achievements, lessons learned, challenges and gaps in discovery‐to‐delivery research in legumes emanating from three projects, collectively called Tropical Legumes (TL) with a total investment of about US$ 67 million funded by the Bill & Melinda Gates Foundation. These projects were implemented by three CGIAR centres (ICRISAT, CIAT and IITA) together with 15 national agricultural research system partners in sub‐Saharan Africa and South Asia. The TL projects together with some of their precursors and complementary projects from other agencies, facilitated the development of 266 improved legume varieties and the production of about 497,901 tons of certified seeds of the target legume crops in the focus countries. The certified seeds have been planted on about 5.0 million ha by more than 25 million smallholder farmers in the 15 countries and beyond, producing about 6.1 million tons of grain worth US$ 3.2 billion. Furthermore, the projects also trained 52 next generation scientists that included 10 women, by supporting 34 Masters degrees and 18 PhD degrees.  相似文献   

6.
Summary Necrotrophic pathogens of the cool season food legumes (pea, lentil, chickpea, faba bean and lupin) cause wide spread disease and severe crop losses throughout the world. Environmental conditions play an important role in the development and spread of these diseases. Form of inoculum, inoculum concentration and physiological plant growth stage all affect the degree of infection and the amount of crop loss. Measures to control these diseases have relied on identification of resistant germplasm and development of resistant varieties through screening in the field and in controlled environments. Procedures for screening and scoring germplasm and breeding lines for resistance have lacked uniformity among the various programs worldwide. However, this review highlights the most consistent screening and scoring procedures that are simple to use and provide reliable results. Sources of resistance to the major necrotrophic fungi are summarized for each of the cool season food legumes. Marker-assisted selection is underway for Ascochyta blight of pea, lentil and chickpea, and Phomopsis blight of lupin. Other measures such as fungicidal control and cultural control are also reviewed. The emerging genomic information on the model legume, Medicago truncatula, which has various degrees of genetic synteny with the cool season food legumes, has promise for identification of closely linked markers for resistance genes and possibly for eventual map-based cloning of resistance genes. Durable resistance to the necrotrophic pathogens is a common goal of cool season food legume breeders.  相似文献   

7.
笔者从食用豆抗性种质资源的筛选与鉴定、抗性机制、抗性遗传规律研究及基因标记3个方面对食用豆抗性育种研究进行了综述,回顾并总结了前人在食用豆抗性育种方面所取得的成果,重点阐述了抗性相关基因(Br)的研究动态,指出今后的研究方向主要集中在抗性相关基因(Br)的定位及功能验证方面,并就目前所遇到的困难进行了讨论与分析,探讨了抗豆象育种的重要性,并对今后的研究方向进行了规划。以期对促进国内食用豆抗性育种研究有所裨益。  相似文献   

8.
我国绿豆品种现状及发展趋势   总被引:1,自引:0,他引:1  
绿豆是我国种植的主要食用豆之一,在我国农产品出口、调整种植结构、丰富人们膳食和农产品加工利用等方面具有重要作用。自20世纪80年代中期以来,我国共育成绿豆品种141个,育种手段实现了从农家品种提纯复壮、优异品种引进、系统选育、辐射诱变到杂交选育的转变,解决了绿豆品种中存在的生育期长、蔓生倒伏、产量低、抗性和适应性差等问题。特别是国家食用豆产业技术体系运行以来,杂交选育与分子标记辅助选择的结合,使新品种的产量、抗病虫性和适宜机械化收获等特性进一步提高。然而,受多种因素的影响,我国绿豆产业出现了种植面积先增后减、进口量连年增加、适宜机械化生产的优质专用和多抗品种缺乏等问题。本文在分析我国绿豆产业及品种发展状况的基础上,讨论了目前我国绿豆品种存在的问题,提出了今后绿豆品种改良的主攻方向,旨在为我国绿豆产业发展和品种改良等提供参考。  相似文献   

9.
A number of improved cultivars of food legume crops have been developed and released in the tropics and the sub-tropics. Most of these cultivars have been developed through conventional breeding approaches based on the development of crop varieties under optimum soil fertility levels. Nevertheless, it is hardly possible to say that the varietal provisions made by the past approach have been readily accepted, and properly utilized to boost productivity of food legumes grown by resource-poor farmers. The approach itself did not fully appreciate the actual circumstances of the resource-poor farmers where marginal production systems prevail and the poorest farmers could not afford to use cultivars developed under optimum soil fertility level. Therefore, the limitations and strategic implications of past experiences made to develop crop cultivars need to be analyzed in order to formulate better strategies and approaches in the future. The main purpose of this article is to review the efforts made, the technical difficulties associated with the genetic improvement in food legumes as related to plant-nutrient relations, causes of limited breeding success and thereby draw lessons useful to designing future breeding strategies. The scope of nutrient deficiency stress and the approaches to breeding for plant-nutrient relations are discussed and the need for refining the approach and better targeting of the breeding methodologies suggested.  相似文献   

10.
Common bean (Phaseolus vulgaris L.) is an important legume crop worldwide. The International Centre for Tropical Agriculture (CIAT) and its national partners in Africa aim to overcome production constraints of common bean and address the food, nutrition needs and market demands through development of multitrait bean varieties. Breeding is guided by principles of market‐driven approaches to develop client‐demanded varieties. Germplasm accessions from especially two sister species, P. coccineus and P. acutifolius, have been utilized as sources of resistance to major production constraints and interspecific lines deployed. Elucidation of plant mechanisms governing pest and disease resistance, abiotic stress tolerance and grain nutritional quality guides the selection methods used by the breeders. Molecular markers are used to select for resistance to key diseases and insect pests. Efforts have been made to utilize modern genomic tools to increase scale, efficiency, accuracy and speed of breeding. Through gender‐responsive participatory variety selection, market‐demanded varieties have been released in several African countries. These new bean varieties are a key component of sustainable food systems in the tropics.  相似文献   

11.
针对20世纪80年代中期川、渝麦区育种方向及审定品种与生产实践需要之间的矛盾,从生产发展、市场经济和人民需要出发,分析了当时审定小麦品种较多而推广应用较少的现象,总结了小穗小粒红皮种推广速度慢,农民不愿种植,大穗大粒白皮种推广速度快的原因。提出了“选育商品型高产优质抗病大穗大粒耐穗发芽白皮小麦新品种”的育种新方向。经过二十几年的努力,培育出了‘绵阳25’、‘绵阳26’、‘绵阳27’、‘绵阳28’、‘绵阳31号’、‘西科麦1号’、‘西科麦6号’等白皮小麦新品种,这些品种成为了四川省小麦第6次大更换的当家品种。为四川省和中国的小麦育种、小麦生产及国家的粮食安全作出了巨大贡献。通过以上品种的推广种植,表明白皮小麦品种在产量、品质、抗病性等方面不亚于红皮小麦品种,而在商品价值、推广速度方面明显优于红皮种。由此认为,突破传统红皮小麦品种容易选育审定的束缚,将市场经济、人们需求、社会发展紧密结合,选育商品型高产、优质、抗病、大穗大粒耐穗发芽小麦新品种将是西南麦区小麦育种的新方向。  相似文献   

12.
Grain legumes serve as key sources of dietary protein to the global human population. Consequence of high‐temperature (HT) stress is increasingly evident as drastically lost production of different crops including grain legumes worldwide, thus putting the global food security under great threat. In a changing climate scenario, cool season‐adapted grain legumes frequently encounter heat stress (HS) during their reproductive phase, thus witnessing serious yield losses. To combat the emerging challenges of HT stress, an integrated approach demanding collaborative efforts from various disciplines of plant science should be in place. This review summarizes major impacts of HT stress on grain legume, and captures the relevance of crop genetic resources to HS tolerance in these crops. Measurement of physiological traits assumes key place in view of ever‐increasing precision of next‐generation phenotyping assays. We also discuss the significance of genetic inheritance and QTL discovery and evolving “omics” science for developing HS tolerance grain legume crops.  相似文献   

13.
开展水稻品种纯度和真实性鉴定对水稻遗传育种和种子生产有着重要的意义。以245个长江中下游主推水稻品种为研究材料,从643个插入缺失(InDel)位点中筛选出124个功能性多态性位点,建立了InDel高效检测体系。进一步利用InDel标记vf0121641804和SSR标记RM7120分析水稻样品的纯度,同时选用覆盖12条染色体的24对InDel引物和48对SSR标准引物分析水稻品种真实性,结果表明,采用InDel标记检测水稻品种纯度和真实性的结果与采用SSR标记检测结果一致,说明水稻功能性InDel标记也可用于水稻品种纯度和品种真实性的鉴定。在此基础上,鉴定了245个水稻品种124个InDel标记的基因型遗传多样性并进行了聚类分析,结果表明,水稻材料间存在明显的群体结构,基本反映了不同品种间的亲缘关系。水稻功能性InDel标记的筛选与应用,不仅为品种纯度和真实性鉴定、遗传多样性分析提供了新方法;而且可用于分子辅助育种,提高强优势组合的预见性。  相似文献   

14.
Summary Soil-borne fungal diseases are among the most important factors, limiting the yield of grain legumes in many countries worldwide. Root rot, caused by Aphanomyces euteiches, Rhizoctonia solani, Fusarium solani and wilt, caused by several formae speciales of Fusarium oxysporum are the most destructive soil-borne diseases of pea, chickpea, lentil, fababean and lupin. The most effective control of these diseases is achieved through the use of resistant varieties. In this paper, recent advances in conventional and innovative screening methods for disease resistance are presented. Many grain legume accessions, which are maintained in national and international germplasm collections, have been evaluated for disease resistance and numerous resistant varieties have been released following incorporation of identified resistance genes from these sources. Recent identification of molecular markers tightly linked to resistance genes has greatly enhanced breeding programs by making marker assisted selection (MAS) possible and allowing the development of varieties with multiple disease resistance. Progress in the understanding of the biology of soil-borne fungal pathogens of grain legumes is also reviewed with particular reference to the genetic structure of their populations, diagnosis and host–pathogen interaction.  相似文献   

15.
Groundnut is an important food and oil crop in the semiarid tropics, contributing to household food consumption and cash income. In Asia and Africa, yields are low attributed to various production constraints. This review paper highlights advances in genetics, genomics and breeding to improve the productivity of groundnut. Genetic studies concerning inheritance, genetic variability and heritability, combining ability and trait correlations have provided a better understanding of the crop's genetics to develop appropriate breeding strategies for target traits. Several improved lines and sources of variability have been identified or developed for various economically important traits through conventional breeding. Significant advances have also been made in groundnut genomics including genome sequencing, marker development and genetic and trait mapping. These advances have led to a better understanding of the groundnut genome, discovery of genes/variants for traits of interest and integration of marker‐assisted breeding for selected traits. The integration of genomic tools into the breeding process accompanied with increased precision of yield trialing and phenotyping will increase the efficiency and enhance the genetic gain for release of improved groundnut varieties.  相似文献   

16.
品种遗传多样性和指纹图谱是育种、品种权保护和新品种推广等工作的重要参考和依据。本研究选用38个来自国家甘蔗品种区域试验的甘蔗新品种(系), 以9对AFLP标记扩增出348个位点, 多态性位点248个, 多态性比率为72.26%; 15对SSR标记扩增出180个位点, 多态性位点176个, 多态性比率为97.78%。38个新品种(系)的遗传相似系数分布在0.668~0.847之间, 其箱线图分布特征显示, 其中的FN、MT、YZ、YG、GT等系列品种(系)遗传基础相似。通过UPGMA聚类表明, 可在遗传相似系数为0.732处将38个甘蔗新品种(系)划分为2个群体, 其中福农09-2201和桂糖06-1492作为一个子群体最先被划分出来, 它们在群体中的异质性较强; 另外, 在遗传相似性系数为0.770处划分出一个子群体a, 其中包含参照品种ROC22、福农07-3206、福农40、海蔗22、桂糖09-12、柳城07-150等品种(系)。ROC22具有广适应性和高产高糖等优良特性, 子群体a中的另外几个品种(系)则更有可能拥有这些特性, 具有更高的推广潜力。本研究选择60个SSR位点构建了38个甘蔗新品种(系)的指纹图谱, 对品种鉴定及品种权的保护具有重要作用, 可望直接应用于指导甘蔗种质资源的遗传多样性评价和分子指纹图谱鉴定, 并将为这些品种(系)推广布局或作为杂交亲本利用提供参考和借鉴。  相似文献   

17.
Grain legumes, the important constituents of sustainability‐based cropping systems and energy‐limited vegetarian diets have long been the subject of scientific research. Tremendous technological strides were made in the so‐called orphan crops, in terms of both varietal improvement and generation of basic information. Despite recalcitrancy and high genotype dependency, in vitro culture techniques such as organogenesis, in vitro mutagenesis, embryo rescue and in vitro gene transfer have been deployed for improvement of several grain legumes and these played an important role in introgression of desirable genes from related and distant species and creation of additional genetic variability. Stable and reproducible regeneration protocols resulted in the development of genetically modified chickpea, pigeon pea, cowpea, mungbean, etc., while embryo rescue was deployed successfully for recovery of interspecific recombinants, a few of them exploited for the development of commercial cultivars. Nevertheless, doubled haploidy witnessed limited success and protoplast regeneration and in vitro mutagenesis remained of academic interest. The present review focuses on the progress, achievements, constraints and perspectives of using in vitro technology in grain legume improvement.  相似文献   

18.
Dairy livestock production systems rely on high‐quality forage legumes, which are widely present in grassland swards all over Europe. A future climatic scenario with higher average annual temperatures and lower precipitation is expected to affect grassland productivity in general and the productivity of the most important forage legume species Trifolium repens in particular. One way to cope with such constraints is the adoption of currently underutilized minor legume species with a higher tolerance towards drought stress. Therefore, the present study investigated legume species with lower moisture requirements than T. repens, these are Lotus corniculatus, Medicago falcata, Medicago lupulina and Onobrychis viciifolia in comparison with T. repens. Legumes were grown in containers as monocultures in a roofed open‐sided greenhouse under conditions of optimal water supply or periodic drought stress. Generally, drought stress decreased the biomass production, but species differed in their reaction. Particularly, M. lupulina and L. corniculatus had lower relative biomass losses (?26%) compared to T. repens (?43%, as averaged over drought stress periods). However, in overall biomass production T. repens still was at one level with M. lupulina and L. corniculatus under drought stress. This was related to high stomata control as indicated by the intrinsic water‐use efficiency. We conclude that there are promising future options of forage legumes as alternatives to T. repens.  相似文献   

19.
Paolo Ranalli 《Euphytica》2004,140(1-2):121-131
Summary Hemp is a multi-use crop, able to provide fiber, cellulose, seeds and seed oil, cannabinoid, and biomass. Integrating many agroindustrial chains, Cannabis is considered a crop model in which insights into specific metabolic pathways and biosynthetic processes are valuable for improvement of the plant for all sets of industrial derivatives. In this review the hemp breeding status is elucidated and many aspects are focused: (i) recovering, maintenance and characterization of genetic resources; (ii) widening of germplasm and genetic variability; (iii) marker-assisted selection and development of breeding programs; (iv) sexual differentiation; (v) monitoring of THC content. Modern hemp varieties for fiber and other specific end uses have been developed and new varieties are entering production. The scenario for the breeding advances in hemp relies on basic and applied research which provides insights to identify a strategy for the design of modified plants with enhanced performance. This is accounted by the dissection of traits into components and the modification of single steps of the related metabolic pathways. These advances are provided by genomic techniques and are able: (i) to identify key genes encoding enzymes and regulatory factors participating in cannabinoid, fiber and oil biosynthesis; (ii) to identify the mode of regulation of these genes; (iii) to characterize the function of the selected genes through higher, lower or specific expression incited by specific promoters. The identification of molecular markers for specific traits, gathered in a saturated linkage map, will have a remarkable impact on hemp breeding. The advances in basic and applied research make it possible to design methods for the identification of superior parents and cross combinations and the development of selection schemes that rely on less labour-intensive and time-consuming methods.  相似文献   

20.
The objective of this study was to assess genetic diversity within old and modern common spring wheat (Triticum aestivumL.) varieties cultivated in Siberia and to find out whether old Siberian varieties could be a potential source for genetic diversity in modern wheat breeding in Siberia. A set of 54 varieties was analysed using 22 wheat microsatellite markers (WMS), determining 23 loci located on 19 different chromosomes. In total, 151 alleles were detected with an average of 6.6, ranging from three to 11 alleles per locus. The average genetic diversity value (polymorphic information content) was 0.70. WMS located in the B genome produced more alleles per locus (7.6) compared with WMS located in the A (6.0) and D (6.0) genomes. Genetic similarity values between varieties ranged from 0.19 to 0.96 and were used to produce a dendrogram. With a few exceptions the varieties studied were clustered in two nearly equal groups consisting of predominantly old (released before 1960) and modern (released in 1960‐90s) varieties, respectively. Genetic diversity values within these two groups were similar with 0.60 and 0.58, respectively. The numbers of group‐specific alleles were 34 and 29, respectively. A significant variation in frequencies of 79 shared alleles was observed. The results obtained by using genomic microsatellite sequences demonstrated that breeding has not resulted in a decrease in the genetic diversity in Siberian spring wheat. However, significant quantitative and qualitative changes in allelic frequencies of different loci were detected. It may be suggested, that old Siberian common spring wheat varieties are a potential basis for genetic diversity in modern wheat breeding in Siberia.  相似文献   

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