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1.
Kulbhushan Saxena Abhishek Bohra Arbind K. Choudhary Rafat Sultana Mamta Sharma Lekha T. Pazhamala Rachit K. Saxena 《Plant Breeding》2021,140(1):74-86
Pigeonpea is an important food legume crop of semi‐arid tropical regions. Plateauing of pigeonpea yield has been worrying breeders for the past 6–7 decades. Serious breeding efforts made during this period resulted in various high‐yielding and disease resistant cultivars. However, the gains in pigeonpea productivity have been modest. The authors, while reviewing this situation, conclude that long generation turnover, complexity of biological traits, low selection response and overreliance upon pedigree breeding present the key bottlenecks for this situation. In this paper, some alternative breeding approaches and technologies are suggested for the genetic enhancement of yield stability and stress response of pigeonpea. 相似文献
2.
Seleman R. Kaoneka Rachit K. Saxena Said N. Silim Damaris A. Odeny Nadigatla Veera Prabha Rama Ganga Rao Hussein A. Shimelis Moses Siambi Rajeev K. Varshney 《Plant Breeding》2016,135(2):148-154
Pigeonpea (Cajanus cajan [L.] Millspaugh) is an important multipurpose grain legume crop primarily grown in tropical and subtropical areas of Asia, Africa and Latin America. In Africa, the crop is grown for several purposes including food security, income generation, livestock feed and in agroforestry. Production in Eastern and Southern Africa (ESA) is however faced with many challenges including limited use of high‐yielding cultivars, diseases and pests, drought, under‐investment in research and lack of scientific expertise. The aim of this review is to highlight the challenges facing pigeonpea breeding research in ESA and the existing opportunities for improving the overall pigeonpea subsector in the region. We discuss the potential of the recently available pigeonpea genomic resources for accelerated molecular breeding, the prospects for conventional breeding and commercial hybrid pigeonpea, and the relevant seed policies, among others, which are viewed as opportunities to enhance pigeonpea productivity. 相似文献
3.
To meet the challenges of climate change, exploring natural diversity in the existing plant genetic resource pool as well as creation of new mutants through chemical mutagenesis and molecular biology is needed for developing climate‐resilient elite genotypes. Ever‐increasing area under existing abiotic stresses as well as emerging abiotic stress factors and their combinations have further added to the problems of the current crop improvement programmes. However, with the advancement in modern techniques such as next‐generation sequencing technologies, it is now possible to generate on a whole‐genome scale, genomic resources for crop species at a much faster pace with considerably less efforts and money. The genomic resources thus generated will be useful for various plant breeding applications such as marker‐assisted breeding for gene introgression, mapping QTLs or identifying new or rare alleles associated with a particular trait. In this article, we discuss various aspects of generation of genomic resources and their utilization for developing abiotic stress‐tolerant crops to ensure sustainable agricultural production and food security in the backdrop of rapid climate change. 相似文献
4.
Jiffinvir S. Khosa John McCallum Ajmer S. Dhatt Richard C. Macknight 《Plant Breeding》2016,135(1):9-20
Bulb onion (Allium cepa L.) is an ancient crop that is thought to have originated in Central Asia and has been cultivated for over 5000 years. Classical genetic and plant breeding approaches have been used to improve onion yield, quality, and resistance against biotic and abiotic stresses. However, its biennial life cycle, cross‐pollinated nature and high inbreeding depression have proved challenging for the characterization and breeding of improved traits. New technologies, notably next‐generation sequencing, are providing researchers with the genomic resources and approaches to overcome these challenges. Using these genomic technologies, molecular markers are being rapidly developed and utilized for germplasm analysis and mapping in onion. These new tools and knowledge are allowing the integration of molecular and conventional breeding to speed up onion improvement programmes. In this review, we outline recent progress in onion genomics and molecular genetics and prospects for enhancing onion yield and quality in the future. 相似文献
5.
Genomic selection employs genome‐wide marker data to predict genomic breeding values. In this study, a population consisting of 391 lines of elite winter oilseed rape derived from nine families was used to evaluate the prospects of genomic selection in rapeseed breeding. All lines have been phenotyped for six morphological, quality‐ and yield‐related traits and genotyped with genome‐wide SNP markers. We used ridge regression best linear unbiased prediction in combination with cross‐validation and obtained medium to high prediction accuracies for the studied traits. Our results illustrate that among‐family variance contributes to the prediction accuracy and can lead to an overestimation of the prospects of genomic selection within single segregating families. We also tested a scenario where estimation of effects was carried out without individuals from the family in which breeding values were predicted, which yielded lower but nevertheless attractive prediction accuracies. Taken together, our results suggest that genomic selection can be a valuable genomic approach for complex agronomic traits towards a knowledge‐based breeding in rapeseed. 相似文献
6.
In 1977, a fodder turnip breeding programme was started from seven cultivars with the primary aim of increasing dry‐matter yield. The breeding method chosen was population improvement by half‐sib family selection on a biennial cycle. Seed production in polythene tunnels with blowflies as pollinators was followed by assessing the resulting progenies in replicated yield trials and observation plots from which plants were selected for the next cycle. Six generations of selection resulted in a population with a yield that was 25% higher than the mean of the initial seven cultivars. This was remarkably close to the predicted superiority of the population, despite a significant discrepancy in one generation. It is concluded that the greatest response to selection per year would be achieved by selecting eight families from 128 assessed for 1 year in trials at two or three sites with an overall total of six replicates, given a resource limit of 800 plots. 相似文献
7.
Use of immature seed germination and single seed descent for rapid genetic gains in pigeonpea 
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下载免费PDF全文 Long duration required for generation advancement in pigeonpea [Cajanus cajan (L.) Millsp] is one of the major bottlenecks in realizing rapid genetic gains. Therefore, a technology for rapid generation turnover is warranted to facilitate the development of new cultivars and recombinant inbred lines. Breeding of early‐maturing cultivars has now opened up the possibility of rapid generation advance (RGA) in this crop. This paper reports the development of an RGA technology that integrates the germination of immature seeds with single seed descent method of breeding. The results showed that immature 35‐day‐old seeds can be used successfully to turn over a generation of pigeonpea with 100% seed germination. These way 3/4 successive generations can be grown within a year. The methodology presented in this study will accelerate the breeding process for breeding cultivars and develop rapidly the materials required for genomics research in pigeonpea. 相似文献
8.
Haile Desmae Pasupuleti Janila Patrick Okori Manish K. Pandey Babu N. Motagi Emmanuel Monyo Omari Mponda David Okello Dramane Sako Candidus Echeckwu Richard Oteng‐Frimpong Amos Miningou Chris Ojiewo Rajeev K. Varshney 《Plant Breeding》2019,138(4):425-444
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
9.
Maternal inheritance of male sterility in the progeny of a natural hybrid between Cajanus lineatus and C. cajan 下载免费PDF全文
下载免费PDF全文 Kul Bhushan Saxena Ravikotti Vijaya Kumar Rama Rao Rachit Kumar Saxena 《Plant Breeding》2018,137(2):229-233
Adoption of pigeonpea hybrids in central and southern India is showing high impact with on‐farm yield advantages of >30%. The hybrid pigeonpea technology, the first in any legume crop, is based on a cytoplasmic‐nuclear male‐sterility (CMS) system. For a long‐term sustainability of hybrid programme, it is imperative that both nuclear diversity and cytoplasmic diversity are maintained among hybrid parents. In this context, a continuous search for new CMS‐inducing cytoplasms is necessary. This paper reports detection of maternal inheritance of male sterility in the progeny derived from a natural hybrid between a wild relative [Cajanus lineatus (W. & A.) Maesen comb. nov.] of pigeonpea and an unknown pigeonpea [Cajanus cajan (L.) Millsp.] genotype. In the present study, the male sterility was maintained up to BC7F1 generation by an advanced breeding pigeonpea line ICPL 99044. This male sterility inducing cytoplasm of C. lineatus was tagged as A6. In future, this CMS genetic stock can be used to develop a range of new pigeonpea hybrids with high yield and adaptation. 相似文献
10.
Straighthead is a physiological disorder in rice (Oryza sativa L.) resulting in sterile florets, poorly developed panicles and yield loss. Because of its sporadic nature and unidentified causes for the disorder, molecular marker assisted selection is essential for resistance improvement in breeding programmes. To take advantage of recent advances in gene‐mapping technology, we executed a genome‐wide association mapping to identify genetic regions associated with straighthead disorder using 547 accessions of germplasm from the USDA rice core collection. Straighthead was evaluated in arsenic treated soil and genotyping was conducted with 75 molecular markers covering the entire rice genome about every 25 cM. A mixed‐linear model approach combining the principal component assignments with kinship estimates proved to be particularly promising for association mapping. The extent of linkage disequilibrium was described among the markers. Six markers were found to be significantly associated with straighthead, explaining 35% of the total phenotypic variation. However, only two SSR markers, RM413 and RM277 on chromosome 5 and 12, respectively, have a significant association with low rating indicating straighthead resistance. Confirmation of the marker‐straighthead association using segregating populations is necessary before marker‐assisted selection can be applied. 相似文献
11.
Benjamin J. Hayes Noel O. I. Cogan Luke W. Pembleton Michael E. Goddard Junping Wang German C. Spangenberg John W. Forster 《Plant Breeding》2013,132(2):133-143
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
12.
Generation mean analysis of horticultural traits in mid‐late cauliflower (Brassica oleracea L. var. botrytis) under sub temperate conditions of Western Himalayas 下载免费PDF全文
下载免费PDF全文 Suitable breeding procedure for crop improvement mainly depends on the type and relative amount of genetic components and presence of non‐allelic interactions. Therefore, the study was carried out during three successive rabi seasons 2013‐14, 2014‐15 and 2015‐16 in mid hill zone of North‐western Himalayas, India with objective to estimate the main genetic effects including digenic non‐allelic interactions controlling horticultural traits in cauliflower. The generation mean analysis was carried out on six generations (P1, P2, F1, F2, B1 and B2) of six crosses involving four diverse parents of cauliflower. The results obtained revealed that the nature and magnitude of gene effects differed in different crosses and showed importance of duplicate epistasis in the inheritance of curd diameter and curd size index, whose effect can be wiped out by following sophisticated selection procedure such as reciprocal recurrent selection and/or biparental mating in early segregating generation. Complementary type of epistasis was recorded in most of the cross combinations for the important yield traits, which indicates the importance of heterosis breeding for the development of high yielding varieties. 相似文献
13.
Strategies employed by dry bean breeders to improve yield include early generation testing, ideotype breeding, selection for
physiological efficiency, and selection based on genotypic performance and combining ability across gene pools of Phaseolus
vulgaris. Ideotype breeding has been successfully deployed to improve yield in navy, pinto and great northern seed types.
The ideotype method is based on an ideal plant architecture to which breeders target their selection. Breeding for physiological
efficiency is important in combining increased biomass, high growth rates and efficient partitioning. Genotypic performance
and combining ability are also critical for yield improvement, since crosses between gene pools can exhibit negative combining
ability and problems with lethality, whereas interracial crosses within the same gene pool exhibit the greatest potential.
Breeders must work within specific constraints for growth habit, maturity, seed quality and disease resistance. A three-tiered
pyramidal breeding strategy is proposed to facilitate yield improvement in dry bean. Breeding of elite, agronomically acceptable
germplasm within the same market class is restricted to the apex of the pyramid. The intermediate level has fewer constraints
and greater access to diverse germplasm. Interracial crosses within the same gene pool are utilized to exploit genetic differences
within adapted material. Extracting genetic diversity from unadapted sources, including wild germplasm and other Phaseolus
species, is conducted at the base of the pyramid. The objective of this breeding strategy is the movement of improved germplasm
towards the apex, using different breeding procedures to optimize improvement at each tier of the breeding pyramid.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
14.
Wheat breeders rarely apply population improvement schemes or select parental sources according to combining ability and heterotic patterns. They rely on pedigree selection methods for breeding new cultivars. This experiment was undertaken to assess the advantages of using diallel crosses to define combining ability and understand heterosis in a broad‐based wheat‐breeding population across different environments affected by yellow rust. Sixty‐four genotypes derived from a full diallel mating scheme were assessed for grain yield in two contrasting growing seasons at two locations for two consecutive years. Parental genotypes showed significant combining ability for grain yield that was affected by yellow rust and genotype‐by‐environment (GE) interactions, both of which affected heterosis for grain yield. Significant GE interactions suggested that decentralized selection for specific environments could maximize the use of this wheat germplasm. Cultivar effects and specific heterosis were the most important factors influencing grain yield. Some crosses capitalized on additive genetic variation for grain yield. This research shows the power of available quantitative breeding tools to help breeders choose parental sources in a population improvement programme. 相似文献
15.
木豆种质资源AFLP标记遗传多样性分析 总被引：6，自引：0，他引：6
利用AFLP分子标记技术,以木豆野生种(Cajanus scarabaeiodes)为对照,对来自印度、中国、非洲和美洲的139份栽培木豆(Cajanus cajan)种质遗传多样性进行研究。17对引物共扩增出502条清晰可辨的带,其中多态性带494条。遗传相似性系数UPGMA聚类图,揭示木豆种内存在足够的遗传多样性,可用于种质资源的准确鉴别与分类。借助遗传距离的ME进化树又将参试种质分成8个组群。分析结果表明,印度地方资源遗传多样性广泛,育成品种遗传基础广阔;非洲、美洲资源遗传多样性较丰富,且与印度资源的亲缘关系较密切。中国地方资源遗传多样性独特,且与印度、非洲、美洲栽培木豆资源亲缘关系不明显。研究结果基本支持印度木豆起源和多样性中心、非洲次生多样性中心的观点,并提出中国次生起源中心和遗传多样性中心假说。研究还发现,木豆核质互作雄性不育系(A)和保持系(B)间存在独特的AFLP谱带差异,可能有助于分子标记辅助的木豆杂种优势利用和杂交种培育。 相似文献
16.
Sutapa Dutta Ajay K. Mahato Priti Sharma Ranjeet S. Raje Tilak R. Sharma Nagendra K. Singh 《Plant Breeding》2013,132(2):191-196
Pigeonpea is an important tropical grain legume widely cultivated in South and South‐East Asia for versatile end usage as food, feed, fodder and fuel. Recent publication of draft genome sequence of pigeonpea (‘Arhar’) has allowed mining of large numbers of genomic simple sequence repeat (SSR) markers most of which are either not validated or show very little polymorphism in simple agarose gel–based assays. Here, we describe a special category of 370 validated highly variable ‘Arhar’ genomic SSR (HASSR) markers, which provide much higher level of polymorphism than a random set of SSR markers. These markers were validated for consistent amplification in a set of eight pigeonpea varieties and 152 of these (41%) showed allelic polymorphism on agarose gel electrophoresis. Twenty‐four highest polymorphic HASSR markers were used on a larger set of forty pigeonpea varieties and eight wild Cajanus species for the analysis of genetic diversity and phylogenetic relationship. Genomic HASSR markers described here are highly suitable for genetic diversity and phylogenic studies in pigeonpea. 相似文献
17.
Germplasm improvement is a conceivable solution for increasing food production in developing countries. The objectives of the present study were to incorporate the genetic diversity of two Nicaraguan common bean landraces into a segregating population and to evaluate its potential as breeding material. Adapted landraces PV0006 and PV0023 were selected as parents for single crosses based on molecular and phenotypic characteristics. The results indicate that we succeeded in reshuffling most of the genetic diversity of both parents into a segregating population. The level of allele recombinations suggests that theoretically between 128 and 1024 different pure lines could be obtained. We found putative associations between alleles and yield‐determinant components. Computer simulations demonstrated that the pedigree method and the marker selection of the most segregating individuals in the F1 generation could improve the genetic gains for yield. These findings expose the potential of this segregating population and the feasibility of local landraces for bean improvement. 相似文献
18.
Pooran M. Gaur Srinivasan Samineni Mahendar Thudi Shailesh Tripathi Sobhan B. Sajja Veera Jayalakshmi Durdundappa M. Mannur Adiveppa G. Vijayakumar Nadigatla V. P. R. Ganga Rao Chris Ojiewo Asnake Fikre Paul Kimurto Robert O. Kileo Nigusie Girma Sushil K. Chaturvedi Rajeev K. Varshney Girish P. Dixit 《Plant Breeding》2019,138(4):389-400
Chickpea (Cicer arietinum L.) is a dry season food legume largely grown on residual soil moisture after the rainy season. The crop often experiences moisture stress towards end of the crop season (terminal drought). The crop may also face heat stress at the reproductive stage if sowing is delayed. The breeding approaches for improving adaptation to these stresses include the development of varieties with early maturity and enhanced abiotic stress tolerance. Several varieties with improved drought tolerance have been developed by selecting for grain yield under moisture stress conditions. Similarly, selection for pod set in the crop subjected to heat stress during reproductive stage has helped in the development of heat‐tolerant varieties. A genomic region, called QTL‐hotspot, controlling several drought tolerance‐related traits has been introgressed into several popular cultivars using marker‐assisted backcrossing (MABC), and introgression lines giving significantly higher yield than the popular cultivars have been identified. Multiparent advanced generation intercross (MAGIC) approach has been found promising in enhancing genetic recombination and developing lines with enhanced tolerance to terminal drought and heat stresses. 相似文献
19.
20.
Chris Ojiewo Emmanuel Monyo Haile Desmae Ousmane Boukar Clare Mukankusi‐Mugisha Mahendar Thudi Manish K. Pandey Rachit K. Saxena Pooran M. Gaur Sushil K. Chaturvedi Asnake Fikre NPVR Ganga Rao CV SameerKumar Patrick Okori Pasupuleti Janila Jean Claude Rubyogo Chigeza Godfree Essegbemon Akpo Lucky Omoigui Stanley Nkalubo Berhanu Fenta Papias Binagwa Michael Kilango Magdalena Williams Omari Mponda David Okello Mekasha Chichaybelu Amos Miningou Joseph Bationo Dramane Sako Sory Diallo Candidus Echekwu Muhammad Lawan Umar Richard Oteng‐Frimpong Haruna Mohammed Rajeev K. Varshney 《Plant Breeding》2019,138(4):487-499
Legumes are important components of sustainable agricultural production, food, nutrition and income systems of developing countries. In spite of their importance, legume crop production is challenged by a number of biotic (diseases and pests) and abiotic stresses (heat, frost, drought and salinity), edaphic factors (associated with soil nutrient deficits) and policy issues (where less emphasis is put on legumes compared to priority starchy staples). Significant research and development work have been done in the past decade on important grain legumes through collaborative bilateral and multilateral projects as well as the CGIAR Research Program on Grain Legumes (CRP‐GL). Through these initiatives, genomic resources and genomic tools such as draft genome sequence, resequencing data, large‐scale genomewide markers, dense genetic maps, quantitative trait loci (QTLs) and diagnostic markers have been developed for further use in multiple genetic and breeding applications. Also, these mega‐initiatives facilitated release of a number of new varieties and also dissemination of on‐the‐shelf varieties to the farmers. More efforts are needed to enhance genetic gains by reducing the time required in cultivar development through integration of genomics‐assisted breeding approaches and rapid generation advancement. 相似文献