利用2个F_2群体整合中国豌豆高密度SSR遗传连锁图谱

豌豆(Pisum sativum L.)是一种重要的食用豆类作物,在全世界范围内广泛种植,既可作为人类食物,也可作为牲畜饲料。用SSR标记构建的遗传连锁图谱在豌豆和其他作物的标记辅助育种中发挥着重要的作用。尽管对豌豆遗传连锁作图的研究已有悠久历史,但公众可获得且可转移的SSR标记以及基于遗传独特的中国豌豆种质的高密度遗传连锁图谱仍然有限。为了获得更多可转移的SSR标记和中国豌豆的高密度遗传连锁图谱,本研究首先从自主开发和文献获取的12,491个全基因组SSR标记中筛选了617个多态性SSR标记,并用于G0003973×G0005527 F_2群体遗传连锁图谱的加密。加密后的图谱全长扩展到5330.6 cM,包含603个SSR标记,标记平均间距离8.8 cM,相比之前的图谱有明显改善。基于上述结果,我们又筛选了119个具有多态性的SSR标记,用于构建大样本W6-22600×W6-15174 F_2群体的遗传连锁图谱,新图谱累积长度为1127.1 cM,包含118个SSR标记,装配在7条连锁群上。最后,将来自以上2个遗传图谱的数据进行整合,得到了一张覆盖范围6592.6 cM的整合图谱,包含668个SSR标记,由509个基因组SSR、134个EST-SSR和25个锚定标记组成,分布在7条连锁群上。这些SSR标记和遗传连锁图谱将为豌豆的遗传研究和标记辅助育种提供有力工具。

An integrated high-density SSR genetic linkage map from two F2 population in Chinese pea

Pea (Pisum sativum L.) is an important food legume crop grown widely throughout the world for humans or livestock consumption. Genetic linkage map constructed with SSR markers have played a vital role in marker-assisted breeding of many crops including pea. Public available and transferable SSR markers and genetic linkage map with sufficient SSR markers based on genetically distinct Chinese pea germplasm are limited despite a long study history on genetic linkage mapping in pea. In this study, in order to obtain more transferable SSR markers and high resolution genetic linkage maps for Chinese pea, 617 polymorphic SSR markers were firstly screened from 12,491 genome-wide SSR markers and some related literatures by our laboratory, and these SSR markers were used to construct an enhanced genetic linkage map for the G0003973 × G0005527 F₂ population. The enhanced genetic linkage map covered 5330.6 cM in total length containing 603 SSR markers with an average inter-marker distance of 8.8 cM, which was significantly improved both in marker number and in density compared with the previous map. 119 polymorphic SSR markers were screened based on the above results to develop a new map for a large W6-22600 × W6-15174 F₂ population including 118 SSR markers with a cumulative length of 1127.1 cM assembled into seven genetic linkage groups. Furthermore, data from the above two genetic maps were combined to build an integrated map of 6592.6 cM, comprising 668 SSR markers, 509 genomic SSRs, 134 EST-SSRs and 25 anchor markers distributed in seven genetic linkage groups. These SSR markers and genetic linkage maps will provide a valuable tool for the genetic study and marker-assisted breeding in pea.