宁麦9号及其衍生品种的赤霉病抗性分析及抗性溯源

Evaluation and Source Tracing of Resistance to Fusarium Head Blight in Wheat Variety Ningmai 9 and Its Derivatives

针对小麦赤霉病抗性,利用与3个抗扩展性QTL位点、1个抗侵染性QTL位点和1个控制低毒素积累的QTL位点紧密连锁的11个分子标记,对中抗赤霉病小麦品种宁麦9号及其10个衍生品种进行抗性溯源,同时利用单花滴注、病麦粒接种和ELISA方法分别进行赤霉病抗扩展、抗侵染和低毒素积累抗性进行鉴定。结果表明,宁麦9号拥有抗扩展性主效QTL位点Fhb1和Fhb2,其赤霉病抗性来源于亲本扬麦6号。10个衍生品种中,生选4号与宁麦9号的遗传背景高度相似,扬辐麦4号与宁麦9号的遗传相似系数最小。宁麦衍生系的抗扩展与低毒素积累抗性相关性较高,但抗侵染性受环境影响较大,表现更为复杂。不同衍生品种的抗扩展性有差异,但总体毒素含量水平较高。衍生品种宁麦13抗性位点数多于宁麦9号,且赤霉病抗性水平最高,与宁麦9号均可作为抗性亲本直接应用于小麦抗赤霉病育种。本研究为今后赤霉病抗性基因的进一步研究和小麦抗赤霉病分子育种提供理论参考。

To trace the genetic source controlling resistance to wheat Fusarium head blight, we chose 11 molecular markers tightly linked to 3 QTLs for type Ⅱ resistance, 1 QTL for type Ⅰ resistance and 1 QTL for type Ⅲresistance to screen in Ningmai 9, a wheat variety moderately resistant to FHB, and its 10 derivative varieties. In addition, we used grain-spawn inoculation, single-floret injection and ELISA method to evaluate typeⅠ, Ⅱand Ⅲresistance, respectively. The SSR data indicated that Ningmai 9 possessed type Ⅱresistance QTLs Fhb1 and Fhb2 which were derived from parental line Ningmai 6. Among 10 derivative varieties, Shengxuan 4 was the most close to Ningmai 9 while Yangfumai 4 had the lowest genetic similarity coefficients to Ningmai 9. The evaluation data showed that typeⅡresistance of derivatives was relevant to type Ⅲ resistance, while typeⅠresistance, affected by environmental influence, was more difficult to assess and had lower coefficients with typeⅠand type Ⅲ resistance.The derivatives of Ningmai 9 had different FHB resistance but most of them had higher DON content in the grains.The derivative variety Ningmai 13, together with Ningmai 9, could be used as resistant parent in wheat breeding program since it possessed more resistance QTLs than Ningmai 9 and had the best FHB resistance in all derivatives. The results in the present study may provide information on understanding resistance mechanism and on molecular breeding for wheat FHB resistance.