Effect of advanced cycle breeding on genetic diversity in barley breeding germplasm
Effect of advanced cycle breeding on genetic diversity in barley breeding germplasm
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DOI：
10.2135/cropsci2007.07.0415
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发表时间：
2008-05-01
期刊：
影响因子：
2.3
通讯作者：
Smith, Kevin P.
中科院分区：
文献类型：
--
作者：
Condon, Federico;Gustus, Charles;Smith, Kevin P.
植物育种强调在一个封闭的群体（高级循环育种）精英父母之间的杂交被认为是减少遗传多样性。为了评估植物育种对等位基因多样性的影响，我们评估了明尼苏达大学六棱大麦（大麦L.）1958年和1998年之间的育种计划，使用系谱信息，70个简单序列重复（SSR）标记，和一个基因特异性标记。系谱和SSR等位基因多样性指数显示，遗传多样性下降，从平均589个等位基因每个位点的祖先组的2.34个等位基因每个位点在第四个十年的育种。对应分析表明，随着时间的种质分化。在特定的位点，我们检测到随着时间的推移，等位基因的数量减少和没有变化。几个标记位点，表现出减少的等位基因数与抗病性或麦芽质量的主要位点，并推测在育种过程中选择。评估育种种质中基因组上的基因座特异性等位基因变异应鉴定基因组中应保守的区域和基因组中有机会渗入新等位基因多样性而不破坏所需基因复合体的区域。
Plant breeding that emphasizes crosses among elite parents in a closed population (advanced cycle breeding) is presumed to decrease genetic diversity. To assess the effect of plant breeding on allelic diversity, we evaluated regional ancestors, parental lines, and cultivar candidates from the University of Minnesota six-rowed barley (Hordeum vulgare L.) breeding program between 1958 and 1998 using pedigree information, 70 simple sequence repeat (SSR) markers, and a gene specific marker. Pedigree and SSR allelic diversity indices revealed a decrease in genetic diversity, from an average of 5 89 alleles per locus in the ancestors group to 2.34 alleles per locus in the fourth decade of breeding. A correspondence analysis showed differentiation in the germplasm with time. At specific loci, we detected both reductions and no change in the number of alleles over time. Several marker loci that demonstrated a reduction in number of alleles were associated with major loci for disease resistance or malting quality and were presumably under selection during breeding. Assessment of locus-specific allelic variation across the genome in breeding germplasm should identify both the regions of the genome that should be conserved and the regions of the genome where there are opportunities to introgress new allelic diversity without disrupting desirable gene complexes.