QTL Primary Mapping Of Leaf Mould Resistance Of Processing Tomato In Xinjiang

Processing tomato was a kind of trade vegetable grown worldwide, also played an extremelyimportant role in the production of vegetable and the development of the national economy.Processingtomato leaf mould is one of the devastating disease generally occurred in the production of processingtomato and formed outbreak in China.Xinjiang province is the maximum planting and processing base inChina.In order to control the prevalent of diseases and reduce crop losses, developing and using resistancegenes of processing tomato for disease resistance breeding programs is an effective way to resolve theproblem radically.This study mainly deals the screening of processing tomato germplasm resources againstleaf mould and the mapping of QTLs concerning leaf mould, both of which are of great significance forprocessing tomato breeding programs. The mainly results are as follows:1. Through leaf mould resistance identification and SSR markers to genetic diversity analysis of80varieties of processing tomato strains,the minimum disease index is the male parent TD33, and the highestone is female parent.the results indicated that the difference of two parents resistance and susceptibility isobvious. The genetic similarity coefficient between two parents is0.79.Choose TD4606as male parent,TD33as female parent to construct linkage map associated with Cladosporium fulvum.2. Based on220F2population from cross between TD33(the resistance strain)×TD4606(thesusceptible strain), a X2test to the ratio of number of resistance and susceptibility on F2showed that R:Ssegregation ration accorded with ratio of3:1.The results shows resistance to Cladosporium fulvum isdominated by a single dominant gene.The Resistant properties of statistical analyzed on F2:3family linesshowed that the segregation ration has a lot of typical characteristics of quantitative genetics.3. The polymorphisms between the parental lines were detected with550pairs of SSR markers,109(19.8%) of which showed polymorphisms between TD33(the resistance strain) and TD4606(the susceptiblestrain). However, totally73pairs of markers amplified desired polymorphic bands in the F2population, andthey were used to build the genetic linkage map. The total map length was349.422cM; the average distancebetween markers was4.787cM, the6linkage groups number is2at least, up to34. The map provided abasis for the mapping of genes conferring resistance to Cladosporium fulvum of processing tomato.4. There resistant QTLs were detected by composite interval mapping(CIM)method, Six QTLs weredetected on the first,second and fourth linkage group named Qcf1,Qcf2,Qcf3,Qcf4,Qcf5,Qcf6and theyexplained12.77%,10.62%,12.54%,8.20%,8.25%and45.83%of the phenotypic variation, respectively.Qcf1coverage region between28.083cM and28.723cM, the distance of left primers Tomato|TC154876is1cM, Qcf2coverage region between48.327cM and49.015cM, the distance of left and right primersTomato|TC158504,LEaag002is0.312cM and2.003cM, Qcf3coverage region between53.565cM and57.401cM, the distance of left and right primers SSR638,LEac002is1cM and3.243cM, Qcf4coverageregion between19.370cM and22.722cM, the distance of left and right primers Tomato|TC159589,SSR300is2cM and0.682cM, Qcf5coverage region between24.404cM and26.414cM, the distance of left primersSSR300is1cM, Qcf6coverage region between47.025cM and59.465cM, the distance of left primers SSR112is12cM.