甘蓝型油菜2009-2010年候选品种遗传多样性及群体结构

摘要

利用45对SSR(简单序列重复)和5对EST(表达序列标签)- STS(序列标签位点)标记对2009 - 2010年度165份新育成甘蓝型冬油菜品种进行遗传多样性及群体结构分析.50个标记检测到131个多态性片段,每个标记等位变异数由1至7不等,平均为2.62,多态性比率为95.83％,PIC均值0.5198.165份品种在遗传相似系数0.5190～0.9380范围内聚类,平均为0.7214.全部品种多样性指数Shannon(H)0.3144,Simpson(I)0.4703.杂交种整体多样性水平要高于常规种,细胞质不育杂交种略高于细胞核不育杂交种.4个生态区域中华东地区所育品种的两种指数最高,分别为0.314 0(H)和0.4663(I),西北地区最低,为0.2711(H)和0.405 9(I).主成分(PCA)以及群体结构分析均显示细胞核不育杂交种与细胞质不育杂交种两种类型间以及中南与西北区域细胞质不育杂交种间存在遗传差异.165份材料群体结构分为8个组.组Ⅰ中质不育杂交种占50％,核不育杂交种和常规种各占近25％；组Ⅱ、Ⅳ、Ⅵ、Ⅶ基本为细胞质不育杂交种；Ⅲ、Ⅴ、Ⅷ三个组以细胞核不育杂交种为主.在细胞质不育杂交种为主的组中,西北区域与中南区域育成品种存在较明显的遗传差异.细胞核不育类型品种为主的3个组显示出更为复杂的遗传背景.%Genetic diversity and structure of 165 candidate cultivars of Brassica napus L. During 2009 and 2010 were evaluated using 45 SSR (simple sequence repeat) primers and 5 EST (expressed sequence tag) - STS ( sequence - tagged site) markers. 131 polymorphic bands were obtained. Mutate allele numbers were between 1 to 7 with average of 2. 62 in each of the primers. Polymorphic rate was 95. 83% , and average PIC value was 0. 519 8. The 165 materials were clustered at a range of 0. 519 0 to 0. 938 0 of genetic similarity with an average of 0. 721 4. Diversity index Shannon ( H) and Simpson (I) were 0. 314 4 and 0. 470 3 respectively. Genetic diversity level in hybrid lines was higher than that in open line materials, while hybrid lines produced by cytoplasmic male sterility (CMS) was slightly higher than those produced by genie male sterility ( GMS). Two diversity indexes 0. 314 0( H) and 0. 466 3(I) were the highest in Huadong region among the 4 ecological regions, while the lowest were in Northwest region, China. PCA ( principal components analysis) and population structure revealed clear difference between CMS and GMS hybrids, as well as among ecological regions in CMS hybrids. Genetic structure of 165 materials were divided into 8 groups. Most of CMS hybrids were in group Ⅱ , Ⅳ , Ⅵ and Ⅷ , and most of GMS hybrids were in group Ⅲ , Ⅴ and Ⅷ There were 50% of CMS hybrids, 25% of GMS hybrids and open lines in Group Ⅰ . The CMS hybrids from Northwestern region and Central - south China exhibited noticeable genetic diversity. And 3 groups involved GMS hybrids showed more complex genetic backgrounds.