Germplasm dynamics: the role of ecotypic diversity in shaping the patterns of genetic variation in Lolium perenne.
Germplasm dynamics: the role of ecotypic diversity in shaping the patterns of genetic variation in Lolium perenne.
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DOI：
10.1038/srep22603
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发表时间：
2016-03-03
影响因子：
4.6
通讯作者：
Hegarty M
中科院分区：
文献类型：
--
作者：
Blackmore T;Thorogood D;Skøt L;McMahon R;Powell W;Hegarty M
多年生黑麦草（Loliumperenne）是世界上分布最广的温带禾本科牧草。与许多其他作物物种相比，黑麦草的集约化植物育种是一项相对较新的工作（过去100年），并提供了一个有趣的实验系统来跟踪现代黑麦草品种中代表的非驯化生态型变异的程度，影响和轨迹。为了探索多年生黑麦草的种质动态，2199个SNPs基因型716个生态型样品从90个欧洲的位置，以及249个品种代表33个饲料/市容加入。此外，对三个假杂交作图群体（450个个体重组体）进行基因分型以创建共有遗传连锁图。多变量分析显示，品种之间的分化很强，改良品种中捕获的生态型变异比例很小。作为经常性选择计划（RSP）的一部分，产生的黑麦草品种与少数地理上本地化的意大利生态型是RSP的创始人之一。单倍型频率的变化揭示了参与水溶性碳水化合物（WSC）积累（RSP中选择的一个性状）的基因puplant中的选择特征。在育种计划（种质动态）种质的回顾性分析提供了一个实验框架，如WSC积累在黑麦草的新性状的候选基因的鉴定。
Perennial ryegrass (Lolium perenne) is the most widely grown temperate grass species globally. Intensive plant breeding in ryegrass compared to many other crops species is a relatively recent exercise (last 100 years) and provides an interesting experimental system to trace the extent, impact and trajectory of undomesticated ecotypic variation represented in modern ryegrass cultivars. To explore germplasm dynamics in Lolium perenne, 2199 SNPs were genotyped in 716 ecotypes sampled from 90 European locations together with 249 cultivars representing 33 forage/amenity accessions. In addition three pseudo-cross mapping populations (450 individual recombinants) were genotyped to create a consensus genetic linkage map. Multivariate analyses revealed strong differentiation between cultivars with a small proportion of the ecotypic variation captured in improved cultivars. Ryegrass cultivars generated as part of a recurrent selection programme (RSP) are strongly associated with a small number of geographically localised Italian ecotypes which were among the founders of the RSP. Changes in haplotype frequency revealed signatures of selection in genes putatively involved in water-soluble carbohydrate (WSC) accumulation (a trait selected in the RSP). Retrospective analysis of germplasm in breeding programmes (germplasm dynamics) provides an experimental framework for the identification of candidate genes for novel traits such as WSC accumulation in ryegrass.