马铃薯晚疫病水平抗性的QTL标记评价

Evaluation of QTL Markers Associated with Horizontal Resistance to Late Blight of Potato

以11个马铃薯晚疫病水平抗性杂交组合后代的636个基因型为材料,对4个与晚疫病(Phy-tophthora infestans)水平抗性相关位于不同染色体的QTL位点标记GP179、GP76、prp1和GP125进行了评价。结果显示:4个QTL位点标记共有6个特征带,在不同遗传背景的组合中带型分布存在差异;田间抗病性与4个标记的总带数呈极显著直线相关;主要成分分析表明,prp1570位点标记解释了供试材料35%的抗性表型变异,为主效QTL。结合抗性表型分析,组合群体的抗性与QTL位点数有关,而个体的抗病水平与主效QTL有关。

To improve the selection efficiency of potato horizontal resistance to late bligh tophthora infestans, molecular markers （GP179, GP76, prpl and GP125 ） of 4 quantitative t caused by Phytrait loci （QTL） linked to potato late blight resistance and located on different chromosomes were evaluated with 636 pedigrees derived from 11 potato crosses with parental materials possessing horizontal resistance to late blight. The re- suits showed that there were 6 bands produced by all the 4 markers and band distribution varied with crosses that have different genetic background. The resistance level of the pedigrees identified in the field was significantly related to the total number of the bands yielded by the 4 markers with a linear function. The dominant component analysis revealed that locus prp1570 explained 35% of the phenotypic variance of the resistance and its linked QTL was hence classified as a dominant locus of late blight resistance. Combining the phenotypic analysis together, the experimental results have reinforced the evidence that late blight resistance is related to the number of QTLs when a whole potato population （ i. e. all pedigrees of a cross） is taken into account and the dominant locus determined the resistance level of individuals within this population.