小麦赤霉病的抗性遗传分析

为给小麦抗赤霉病遗传改良提供参考，利用苏麦3号及5个当地推广小麦品种为亲本，按Griffing双列杂交法Ⅱ配制15个杂交组合，以赤霉病病小穗率为抗性指标，研究了小麦赤霉病抗性的遗传。结果表明，在6个小麦品种中，苏麦3号和扬麦9号赤霉病抗性的一般配合力最好，能极显著地提高杂种后代的赤霉病抗性。小麦赤霉病抗性的遗传符合加性显性模型，同时受加性和显性效应的作用，且加性效应更重要，显性程度为部分显性。控制赤霉病遗传的增效等位基因为显性，增减效等位基因频率在亲本中的分配存在显著差异。苏麦3号具有最多的控制赤霉病抗性遗传的显性基因，而宁麦8号则具有控制赤霉病抗性遗传最多的隐性基因。小麦赤霉病抗性可能受2~3对主效基因的控制，狭义遗传力较高，早代选择有效。论文最后还就小麦抗赤霉病育种进行了探讨。

Genetic Analysis of Resistance to Fusarium Head Blight in Wheat

In order to promote the genetic improvement for resistance to Fusarium head blight (FHB, scab) in wheat, genetic analysis was conducted in six parents involving Sumai 3 and five local commercial wheat cultivars, and their F₁ obtained from a diallel cross without reciprocals. The FHB resistance was measured by percentage of scabbed spikelets. The results showed that Sumai 3 and Yangmai 9 had the best general combining ability for resistance to FHB and could increase significantly the resistance to FHB in their crossing progeny. The inheritance of resistance to FHB fit in with the additive dominance model and was controlled by both additive and dominant genetic effects, and the additive effect was much more important than the dominant effect. The degree of dominance was partial dominance. The alleles increasing resistance to FHB were dominant, and the frequency distribution of alleles increasing or reducing resistance to FHB was asymmetry among 6 parents. Sumai 3 had the most dominant genes controlling resistance to FHB, while Ningmai 8 had the most recessive genes. The resistance to FHB might be controlled by two or three pairs of major dominant genes with higher narrow sense heritability. It was feasible on selection of resistance to FHB in the earlier generations.The wheat breeding for resistance to FHB was also discussed in the paper.