小麦抗赤霉病3B-QTL和6B-QTL的遗传互作模式分析
Genetic interaction model analysis of 3B-QTL and 6B-QTL with resistance to wheat scab

为明确来自抗赤霉病的小麦品种望水白的2个主效抗扩展3B-QTL和6B-QTL的抗性遗传和互作模式，基于分子标记辅助选择方法，构建了回交分离群体，以病小穗数（NDS）和病轴长（LDR）为鉴定指标，采用单花滴注接种法对携带3B-QTL和6B-QTL的BC3F1、BC3F2、BC3F3世代以及抗感对照进行了抗赤霉病扩展的表型鉴定和评价。结果表明，3B-QTL和6B-QTL在烟农19和矮抗58不同的背景中，杂合基因型与纯合望水白基因型之间的NDS和LDR差异显著；携带3B-QTL和6B-QTL株系的抗扩展性与只含有单个3B-QTL的株系显著差异，但显著高于只携带单个6B-QTL株系的抗性，抗感分离比经卡方检验符合4：3：9的分离比例，遵循2个独立孟德尔遗传因子控制的隐性遗传模式，且3B-QTL隐性上位于6B-QTL。研究表明，望水白的3B-QTL和6B-QTL抗扩展效应强且稳定，可以作为抗赤霉病基因资源在育种实践中充分利用。
To clarify the resistance heredity and interaction model to wheat scab, 3B-QTL and 6B-QTL deriving from resistant landrace Wangshuibai were identified and evaluated by using single floret inoculation in the BC3F1, BC3F2 and BC3F3 backcrossing generations. The results showed that one or two QTL of heterozygous and homozygous recurrent parent genotypes had significant difference with homozygous donor parents under Yannong 19 and Aikang 58 genetic backgrounds. Meanwhile, the wheat plant stacking 3B-QTL and 6B-QTL represented a better spreading resistance than that of the homozygous donor genotype with single 6B-QTL, but had no significantly difference with the plant of single 3B-QTL. 3B-QTL and 6B-QTL were two independent and recessive factors of Mendelian genetics according to the segregation ratio of the 4:3:9, and 3B-QTL showed the obvious recessive epistasis to 6B-QTL. The results indicated that the spreading resistances of 3B-QTL and 6B-QTL from Wangshuibai were strong and stability, and could be fully utilized as the fine resource of resistance genes in wheat scab breeding.