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71.
Breeding for boron tolerance in lentil (Lens culinaris Medik.) using a high‐throughput phenotypic assay and molecular markers 下载免费PDF全文
Matthew S. Rodda Shimna Sudheesh Muhammad Javid Dianne Noy Annathurai Gnanasambandam Anthony T. Slater Garry M. Rosewarne Sukhjiwan Kaur 《Plant Breeding》2018,137(4):492-501
This study describes the identification of a quantitative trait locus (QTL) in the recombinant inbred line population of ILL2024 × ILL6788 and subsequent validation of associated molecular markers. A high‐quality genetic linkage map was constructed with 758 markers that cover 1,057 cM, with an average intermarker distance of 2 cM. QTL analysis revealed a single genomic region on Lc2 to be associated with B tolerance and accounted for up to 76% of phenotypic variation (Vp). The best markers for B tolerance were assessed for their utility in routine breeding applications using validation panels of diverse lentil germplasm and breeding material derived from ILL2024. A marker generated from the dense genetic map of this study was found to be the most accurate of all markers available for B tolerance in lentil, with a success rate of 93% within a large breeding pool derived from ILL2024. However, given the number of the unrelated lines for which the marker–trait association was not conserved, B tolerance screening is still required at later stages to confirm predicted phenotypes. 相似文献
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Khan Sultan Habibullah Sajjad Muhammad Gulnaz Saima Waqar Sundas Shahzad Munawar Arain Saima Mir 《Journal of Crop Science and Biotechnology》2022,25(2):215-223
Journal of Crop Science and Biotechnology - Understanding genetic architecture of a crop germplasm is necessary for designing a successful breeding program. Herein, we evaluated a large collection... 相似文献
75.
Comparing mating designs to restore seed production of interspecific hybrids between Trifolium repens (white clover) and Trifolium uniflorum 下载免费PDF全文
Muhammad Naeem Isabelle Marjorie Verry Peter D. Kemp James P. Millner Warren Mervyn Williams 《Plant Breeding》2017,136(3):420-426
Interspecific hybrids between Trifolium uniflorum and cultivated white clover (Trifolium repens) have highly useful characteristics for temperate pastoral systems derived from both parent species. However, the early hybrids (F1 and BC1) also have unacceptably poor seed production for commerce. This study analysed the basis for the poor seed production and investigated breeding strategies for overcoming the problem. The BC1F1 generation produced lower‐than‐expected numbers of heads per plant and seeds per floret. Backcrossing of selected hybrids to white clover corrected these deficiencies and created new variation. Seed numbers were also returned to near target levels by recurrent selection within the BC1 generation. Thus, it was possible to retain a theoretical average of 25% of T. uniflorum genome and still achieve high seed production per plant. The BC1F2 and BC2F1 generations produced high seed numbers per plant, along with reasonable variation. Both of these second‐generation hybrid forms have high reproductive potential and should be the focus for the selection of the desired combinations of agronomic and seed production traits. 相似文献
76.
This study was conducted to identify quantitative trait loci (QTLs) for drought tolerance in sorghum (Sorghum bicolor (L.) Moench) by association mapping using a simple sequence repeat (SSR)-marker-based diversity research set. Genotypic data for 98 SSR marker loci on ten chromosomes were used for the association analysis. The experiment was conducted under control (well-watered) and drought stress conditions, and the phenotypic values of 23 morphological traits were recorded. Drought tolerance was assessed by using a leaf drying score as a parameter of the tolerance/susceptibility: scores were assigned on a scale from 1 (most tolerant) to 9 (most susceptible). Under the control conditions, 17 QTLs associated with 12 traits were identified on chromosomes 1, 2, 4, 8, 9, and 10, with ?Log10 (P) ranging from 2.5 to 7.6 and explaining 9.5–57.5 % of the total phenotypic variance for the traits. Under the drought stress conditions, nine QTLs associated with 8 traits were identified on chromosomes 1, 2, 3, and 10 that explained 9–61.2 % of the total phenotypic variance for the traits, with ?Log10 (P) ranging from 2.5 to 3.5. QTLs for some traits were detected only under the drought stress condition, suggesting that these traits are important in drought tolerance. These QTLs could be used to further dissect the genetic and physiological basis of drought tolerance in sorghum. 相似文献
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Wheat is one of the most widely cultivated crops and, being the staple diet of more than 40 countries, it plays an imperative role in food security. Wheat has remarkable genetic potential to synchronize its flowering time with favourable environmental conditions. This ability to time its flowering is a key factor for its global adaptability and enables wheat plant to produce satisfactory grain yield under very diverse temperature and soil moisture conditions. Vernalization (Vrn), photoperiod (Ppd) and earliness per se (Eps) are the three genetic systems controlling flowering time in wheat. The objective of this review is to provide comprehensive information on the physiological, molecular and biological aspects of the three genetic constituents of flowering and maturity time in wheat. Reviews written in the past have covered either one of the aspects; and generally focused on one of the three genetic constituents of the flowering time. The current review provides (a) a detailed overview of all three gene systems (vernalization, photoperiod and earliness per se) controlling flowering time, (b) details of the primer sequences, their annealing temperatures and expected amplicon sizes for all known markers of detecting vernalization and photoperiod alleles, and (c) an up to date list of QTLs affecting flowering and/or maturity time in wheat. 相似文献
79.
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
80.
在阿富汗首都喀布尔的西南部,在飞扬的尘土和战后满目疮痍的城市里,幸运地保留着一块绿树葱茏的清凉绿洲,那就是喀布尔动物园。然而,动物园里并非一派安宁平和,那儿的动物对它们的生存状况极其愤怒,管理员们同样也很生气。 相似文献