| The cereal cyst nematodes(CCN)are recognized as endoparasitie,widely spread in more than 50 countries across the world of five continents and cause significant yield loss in wheat.CCN is a complex population,among which Heterodera avenae and H.filipjevi,have been reported to be a serious threat to wheat yield in our country.At present,the most effective and economy method to control CCN is breeding and planting resistant cultivars to CCN.Through previous work of our laboratory,Taikong 6 and Zhongyu 6 have stable resistance to H.avenae and H.filipjevi.It is of great significance in basic research and practice application to clarify the inheritance of resistance of Taikong 6 and Zhongyu 6 to these two CCN populations and mine resistance genes from local resistance resources.The objectives of this research were to analyze the inheritance of resistance to H.avenae from Xushui,H.filipjevi from Xuchang and Jiaozuo of F2 populations derived from the crosses Wenmai 19 × Zhongyu 6 and Wenmai 19 × Taikong 6.The method of joint segregation analysis of single generation of major gene plus polygene mixed inheritance model was used to analyze the inheritance of resistance in Taikong 6 and Zhongyu 6.A genetic linkage map for target chromosomes constructed using SSR markers and QTL(quantitative trait loci)mapping analysis about the resistance of Taikong 6 to H.avenae was performed by QTL Icimapping v3.2 which based an inclusive composite internal mapping.The detailed results were available as follows:(1)Based on the results of inoculation test and field test,we found that the resistance of common wheat cultivar Taikong 6 to H.avenae(Xushui population)and H.filipjevi(Xuchang population),and that of Zhongyu 6 to H.avenae(Xushui population)and H.filipjevi(Bo’ai population)appeared to be quantitative inheritance.(2)In the inheritance of resistance analysis of Taikong 6 to CCN population,the optimal model for inoculation test of H.avenae(Xushui population)fitted B-2(two major genes with additive-dominance effects)and the heritability of two major genes was 59.62%.The resistance to H.avenae in disease field of Xushui was controlled by two major genes with additive-dominance-epistasis effects(B-1),and the heritability was 78.21%.The resistance to H.filipjevi(Xuchang population)under inoculation condition was according to B-1 model,and the heritability of two genes was 74.62%.The resistance to H.filipjevi in disease field of Xuchang fitted B-2,and the heritability was 80.62%.Under four conditions,the resistance of Taikong 6 to CCN expressed moderate and high heritability and showed that the resistance of Taikong 6 to CCN was controlled by two major genes.(3)In the inheritance of resistance analysis of Zhongyu 6 to CCN population,the optimal model for inoculation test of H.avenae(Xushui population)fitted B-2(two major genes with additive-dominance effects)and the heritability of two major genes was 59.51%.The resistance to H.avenae in disease field of Xushui was also controlled by B-2,and the heritability was 90.31%.The resistance to H.filipjevi(Bo’ai population population)under inoculation condition was according to B-2 model,and the heritability of two genes was 74.83%.Under three conditions,the resistance of Zhongyu 6 to CCN expressed moderate and high heritability and showed that the resistance of Zhongyu 6 to CCN was controlled by two major genes.(4)In the QTL mapping of Taikong 6 to H.avenae Xingyang Population,total of 314 pairs of SSR markers were available with showing polymorphism differences between two parents from 1447 pairs of SSR primers originally selected,the average polymorphism frequency was 20.68%.Linkage genetic map of 1A was constructed and total of 4 SSR markers from 9 pairs of SSR markers were mapped on one linkage group using the MAP in QTL Ici Mapping v3.2.The linkage genetic map was covered 65 c M and the average interval between two SSR markers was 16.25 c M on the linkage map.One major QTL was identified for controlling H.avenae of Taikong 6 by the use of BIP.This QTL could explain phenotypic variation 17.4437%,with marker interval Xgpw7421~WMS136 and named as Qccn.wt-1A-1.Combined with Qccn.wt-2B-1 discovered former,with marker interval WMS47~Barc101 and could explain phenotypic variation 16.4139%,two major QTLs have been found,which in according with the results of the resistance analysis that the resistance of Taikong 6 to CCN is controlled by two major genes.(5)In the QTL mapping of Zhongyu 6 to H.avenae Xingyang Population,total of 285 pairs of SSR markers were available with showing polymorphism differences between two parents from 907 pairs of SSR primers originally selected,these markers were located on chromosomes 1B,2A,2B,2D,3A,3B,3D,5A,5D and 6B.The polymorphism frequency were 36.36%,34.81%,36.22%,31.33%,28.09%,35.00%,26.98%,28.43%,30.61% and 23.81%,respectively.The polymorphism frequency of 1B and 2B were highest,this established the foundation for screening in small population and constructing linkage genetic map later. |
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