Genetic Composition of Elite Soybean Cultivar Hefeng 25

This study evaluated the genetic composition of elite soybean [Glycine max (L.) Merr.] cultivar Hefeng 25, and the genetic relationship between Hefeng 25 and its parents Hefeng 23 and Ke 4430-20. A total of 463 simple sequence repeat (SSR) markers were analyzed on 20 soybean linkage groups, and 177 SSR markers were monomorphic and 57 SSR loci were mutated (novel alleles to the parents). The overall genetic contributions of Hefeng 23 and Ke 4430-20 to Hefeng 25 were 39.4% and 48.3%, respectively. On the 20 linkage groups of Hefeng 25, alleles of loci tested originated differently. All alleles on linkage group G and most alleles on linkage group E were inherited from Ke 4430-20 and most alleles on linkage group L were from Hefeng 23. The combination of alleles on linkage groups in Hefeng 25 is conjectured in relation to the quantitative trait loci (QTLs) for favorable traits, such as yield and disease resistance, and has been selected during breeding process. For evaluating the effect of mutated loci on genetic purity, 12 seed samples of Hefeng 25 obtained from different companies were evaluated using 207 SSR markers including the markers for the 57 mutated loci. Only 4 seed samples had hybrid alleles at 13 loci, indicating that most of the mutated loci were purified. The elite genotype and high seed purity are probably the major factors for the long-term utilization in production of Hefeng 25.

摘 要合丰25由合丰23和克4430-20杂交选育而成, 是我国大豆生产上累计种植面积最大的品种。本研究利用463个SSR标记对合丰25及亲本进行检测, 并分析其遗传组成及其与亲本的遗传关系。463个SSR位点中有177个位点在合丰25的两个亲本间无多态性, 合丰23和克4430-20对合丰25的遗传贡献率分别为39.4%和48.3%。在G和E两个连锁群发现克4430-20有大片段传递给合丰25, 特别是G连锁群没有发现来自合丰23的片段, 而合丰23在L连锁群传递给合丰25的位点是克4430-20的2.3倍。不同连锁群亲本染色体片段的组成不同, 可能与产量、抗病性等重要性状相关QTL的分布有关, 从而使合丰25通过重组集合了两个亲本的优点。合丰25在57个位点出现新等位变异。为分析位点突变对合丰25纯度的影响, 用包括57个位点在内的207个SSR标记对12个不同销售点的合丰25种子进行检测, 207对SSR引物中有13对在4个大豆样本中检测到杂合条带, 而8个样本的纯度均为100%。说明大部分突变位点已在品种利用过程中纯合, 合丰25的优异基因型及其在推广20多年后仍保持的高纯度, 是其在生产上利用经久不衰的主要原因之一。