Association Analysis Of Peach Flesh Texture, Stone Adhesion To Flesh And Firmness

The research contained three parts. In the first part,53pairs of SSR primer located in8scaffolds ofpeach were used to scan the128peach germplasms genome so that we can take advantage of theassociation analysis based on Linkage disequilibrium(LD) to search the maskers of fruit flesh texture,stone adhesion to flesh and firmness. In the second part, the flesh texture candidate gene Endo-PGsequence from27peach materials were sequenced so as to find SNP which will be made associate withthe trait flesh texture and stone adhesion to flesh. In the third part, the relationship of the indel1andindel2with flesh texture and stone adhesion to flesh were analyzed in population of117materials. Themain results were as follows:1.340alleles were detected in128materials from53pairs of SSR primer, the average number ofevery primer was6.9alleles, there were only2alleles in the primers CPSCT008, Epdcu2862,CPSCT044and UDP96-406, while9alleles were detected in BPPCT008, UDP98-407and CPPCT022.2.The software Structure based on mathematrical model was applied to analyse the populationstructure, the result showed that27materials was divided into subpop1,41into subpop2,30intosubpop3and subpop4, respectively. In addition, Q value the probability that the material divided into subpop wascaculated. It will be used as covariant to make association analysis to avoid the subjective error.3.LD levels was analysed by used the Tassel2.1. And its GLM(generallinemodel) was used to makeassociation analysis. The result showed that19SSR marker sites were associated with the trait fleshtexture. Stone adhesion to flesh, flesh firmness with skin and without skin. The former three had5marker sites, and the last have4sites. We positioned, PpACS1, a key gene for ethylene synthsis, itlocated32.7cM in the scaffold2of T×E map, and4.9cM next to UDP96-013. So we can conclude thatPp-ACS1is a key candidate gene that controlled the fruit ripening and softing. Also Endo-PG, acandidate for stone adhesion to flesh as used this method.4.Through sequence comparison with three sequence from GenBank,34polymorphisms sites hadfound, there were three mutation types,16replacements,13transversion and4insertion.Polymorphisms was used to cluster, which was consistent with ecological zone. Through the analysis ofLD about667polymorphisms combinationsites,84combination sites had a high LD level. Nucleotidevariation G/C on site546was significantly associated with traits fruit texture and cling or freestone withphenotypic contributions of54.31%and43.67%, respectively.5.We designed two pairs of primer to detect the genetic distribution of indel1and indel2located inEndo-PG gene in117materials through SDS, the result indicated that indel2had some impact ontexture and stone. adhesion to flesh.