小麦骨干亲本碧蚂4号的基因组特异位点及其在衍生后代中的传递

Specific Loci in Genome of Wheat Milestone Parent Bima 4 and Their Transmission in Derivatives

为探讨小麦骨干亲本碧蚂4号的遗传构成及其特异位点在衍生后代中的传递特点,利用覆盖小麦全基因组的1239个SSR、EST-SSR和STS标记对碧蚂4号子一代衍生品种(系)的4个亲本进行标记筛选,获得33个特异标记可用于76份碧蚂4号衍生材料的分析。在子一代和子二代材料中,除标记Xgwm577外的32个标记均能扩增出碧蚂4号特异带,且分别有8个和10个标记位点的传递频率大于50%;在子三代和子四代材料中能扩增出碧蚂4号特异带的标记分别有29个和20个,传递频率大于50%的标记位点分别有8个和4个;Xgwm261、Xedm80、SWES222和CFE223在4个世代中的传递频率都保持在50%以上;有18个标记位点对衍生品种(系)的遗传贡献率大于25%;推测这些基因组位点及其附近的染色体区域可能是被育种家强烈选择的部分,碧蚂4号含有一些特殊的与重要农艺性状相关的基因组位点/区段,可能是其成为骨干亲本的遗传基础。

Bima 4 is one of the most important milestone parents in China. The objective of this study was to reveal the genetic structure of Bima 4 and the transmission of its specific loci in descendents using molecular markers. A total of 1 239 SSR, EST-SSR and STS markers covering the whole genome of wheat were screened with the four parents of the first progeny of Bima 4, i.e., Bima 4, Early Piemium, Jubileina 2, and Ckopocneaka JI-1. Thirty-three markers were effective to trace the specific loci of Bima 4 in the progenies. Seventy-six derivatives of Bima 4 were genotyped with the 33 markers. In the first and the second generations of Bima 4 derivatives, 32 markers, except for Xgwm577, could amplify the specific bands of Bima 4. The inheritable frequency of the specific loci were 7.1-92.6% in the first generation and 2.9-80.0% in the second generation, of which eight and ten loci showed the transmission percentage larger than 50.0% in the first and the second generations, respectively. In the third and the fourth generations, twenty-nine and twenty specific markers were observed, eight and four loci had the transmission rate higher than 50.0%, respectively. Among the specific loci, Xgwm261, Xedm80, SWES222, and CFE223 possessed the inheritable frequency higher than 50% in all four generations. Another 18 loci of Bima 4 were detected in the progenies with genetic contribution ratio higher than 25%. This indicates that some desirable traits, such as yield, grain quality, disease resistance, and adaptability might be associated with these loci or the nearby chromosome regions in Bima 4, and intensively selected in breeding programs. The important loci detected in this study provide the information for understanding the genetic basis of Bima 4 as a milestone parent in wheat breeding.