普通小麦苗期茎基腐病抗性QTL定位

QTL Mapping for Resistance to Fusarium Crown Rot in Common Wheat at Seedling Stage

茎基腐病(Fusarium crown rot,FCR)已成为影响我国小麦生产的主要病害之一,发掘抗病基因和种质可为解析其抗病遗传机制和聚合育种提供指导。本研究选用藁城8901/周麦16构建的重组自交系(recombinant inbred line,RIL)群体为材料,基于已构建的90K SNP高密度遗传连锁图谱,对接菌条件下苗期FCR抗性进行QTL(quantitative trait loci)定位。结果表明,RIL群体苗期FCR病情指数在基因型和不同试验间均达显著差异(P<0.01)。藁城8901表现为感FCR,周麦16表现为高感FCR,家系表现为连续变异和超亲分离。在3次试验及均值中共定位到14个与苗期FCR抗性显著相关的QTL,分布在1D(2)、3B(2)、4A(2)、5B(2)、5D、6A(4)和7B染色体上,解释表型变异的4.42%~11.37%;其中,4个在两次试验中均被检测到。本研究表明感病和高感亲本也可用于抗病品种的培育和基因发掘,检测到的4个稳定QTL和抗病家系为FCR抗病育种提供了可用的资源。

Fusarium crown rot(FCR)has become one of the main diseases affecting wheat production in China.Identifying the resistance genes and germplasms can provide guidance for the analysis of resistance genetic mechanism and accelerate the progresses of pyramid breeding.In this study,the quantitative trait loci(QTL)for FCR resistance under inoculation at seedling stage were mapped using the recombinant inbred line(RIL)population derived from Gaocheng 8901/Zhoumai 16 cross based on the high-density genetic linkage map using the wheat 90 K SNP arrays.The results showed significant differences(P<0.01)were found among genotypes and tests in the disease index of FCR.Gaocheng 8901 showed moderate susceptibility to FCR and Zhoumai 16 showed high susceptibility to FCR.The distribution of disease index revealed continuous variation and transgressive segregation.Totally,14 QTLs on chromosomes 1 D(2),3 B(2),4 A(2),5 B(2),5 D,6 A(4)and 7 B were identified for FCR in the three tests and mean values,which accounting for 4.42%~11.37%of phenotypic variances.Among which,four QTLs were commonly detected in two tests.All these showed that susceptible and highly susceptible varieties were also available in resistance breeding and gene discovery.The four stable QTLs and resistant RILs detected in this study could provide important resources for FCR resistance breeding.