Genetic Difference of Sib lines Derived from Winter Wheat Germplasm “Aimengniu”

“Aimengniu” (Aifeng 3//Mengxian 201/Neuzucht) is a backbone parent for cultivar improvement of winter wheat (Triticum aestivum L.) in China. Up to 2007, 26 wheat cultivars have been developed from the crosses using Aimengniu as a parent. To disclose the genetic basis of this backbone parent in breeding process, the genetic and phenotypic differences among 7 Aimengniu-derived sib lines (types) were compared based on the results from 656 molecular markers and 16 agronomic traits. There were obvious variations among the 7 Aimengniu-derived types in the traits surveyed. The Aimengniu-derived type V showed better performance on yield components than other types. A graphical genotype integrated map was constructed using the molecular marker data, which showed the inheritance of fragments from the 3 parents to Aimengniu. Two F2 populations (Aifeng 3/Neuzucht and Mengxian 201/Neuzucht) were developed to identify quantitative trait loci (QTLs) for yield-related traits in the Aimengniu-derived type V. Eight loci specific to Aimengniu type V were detected on chromosomes 1A, 1B, 2D, 3A, 4D, and 7A, which were associated with QTLs for yield components. These specific loci might discriminate the type V from other types at genomic level.

摘 要采用田间试验鉴定和基因组分子标记分析相结合的方法, 对冬小麦种质“矮孟牛” 7个类型的性状和基因组遗传差异比较分析。结果表明, 7个类型在调查的株高、穗长、穗粒数、粒长、粒宽、单株穗数等16个性状方面存在差异, 其中矮孟牛V型的主要产量构成因素等性状比较协调, 总体优于其他6个类型。在检测的2210对SSR、EST-SSR和STS标记中, 有656对标记可在矮孟牛三亲本中显示多态性, 将其用于矮孟牛7个类型全基因组遗传差异分析, 并利用GGT2.0绘制7个类型的遗传差异图谱。在矮孟牛V型的1A、1B、2D、3A、4D、7A染色体上检测到8个特异位点, 利用矮丰3号/牛朱特和孟县201/牛朱特构建的2个F2分离群体, 经Ici MappingV3.0单标记QTL作图分析, 发现矮孟牛V型部分特异位点附近存在与产量构成因素等重要性状相关的QTL。矮孟牛V型的基因组特异位点可能是它作为骨干亲本区别于其他姊妹系的重要基因组特征。