Association Analysis Of Agronomic Traits In 96 Mulberry Local Collections

China is thecradle of the world sericulture and is also one of the most important origin centers of mulberry. As an important economic crop of perennial, mulberry is the sole feed of silkworm. The varieties of mulberry, the yield and quality of mulberry leaf are the decisive factor of sericulture. To improve the yield, quality, resistance and adaptability of mulberry is the main goal for the mulberry breeders. In this study, on the basis of mulberry phenotype research, local mulberry varieties in China were used to analyze their correlation to find the excellent genes which are related to phenotypic traits. In this way, we can explain the genetic variation rule of phenotypic traits from molecular level. Then provide fundamental basis for the research of mulberry quantitative traits genetic improvement, and explore the new methods for mulberry crossbreeding.96 mulberry germplasm from Morus multicaulis Perr type of the Yellow River basin and Taihu Basin were used as the experimental material to analyze their correlation among 21 agronomic traits by using ISSR molecular marker technology.With the polymorphism of 10 ISSR markers, we can make an investigation the genetic diversity and population structure, and further on the correlation analysis of markers and agronomic traits.The main results are as the following:1.In this study, the survey of 96 parts mulberry collection 21 agronomic traits using SPSS 17.0 software to analyze the field survey datas is divided into two levels,P<0.01 and P<0.05. The result shows that the variation range of 21 traits are quite different, where in BP, LBS, NA, SSR, FSR, LSR, LYP, the variation coefficient is more than 30%. The variation coefficient of SSR, FSR and LSR even reaches more than 50%. The variation coefficient of FSR, 180.99%, is the largest of all, and the smallest one is ACY, only 9.32%. The differences among the mulberry varieties showed traits are quite different and wide diverse, which can provide abundant parent materials in mulberry breeding.2.Using ISSR technology to analyze the genetic diversity and population structure of 96 mulberry germplasm, a total of 93 bands were amplified with 10 primers, including 73 polymorphic bands. The percentage of polymorphic bands is78.49%. The amplified bands of different primers ranged from 7 to 11. The amplified bands' average was 9.3 per primer, and the polymorphic bands' average is 7.3 perprimer. The analysis result of the genetic diversity shows that the average observed number of alleles per locus was 1.7957, the effective number of alleles was 1.4964,the Nei's genetic diversity index was 0.2869, Shannon's' s information index was0.4268, indicating that the ISSR variation and polymorphism among the 96 tested materials are quiet high. Population structure analysis and cluster analysis are consistent in some extent by using cluster analysis and Structure UPGMA. The population of 96 mulberry germplasm was divided into 2 subgroups.3.Using TASSEL2.1 software mixed linear model(MLM), tke the population structure data(Q value) as the concomitant variable, do the correlation analysis between matrix binding affinity(K) and 93 phenotypic markers and trait data. From the result we can see, among the 93 sites there are 28 sites associated with 15 agronomic traits under the condition of P<0.01. And the phenotypic variation explained by 5.42%~16.35%. Of which, there are 2site associated with LL; each has 3different sites associated with ID, BP and ACY; each has 5 different sites associated with LBS, SCY, and SWM; there are 2 sites with LBA; NS, WSR and LYP associate with 4 sites; NA has only 1 sites associated with; LSR is associated with 6 sites; each has 7 different sites associated with SSR and SCM. Among these 28 sites, there is 1site associated with 5 agronomic characters at the same time, other 4 sites associated with 4 agronomic characters at the same time, another 4 sites associated with3 agronomic characters at the same time, and the other 10 sites associated with2 agronomic characters at the same time. We don't detect out the sites which are associated with LW, GR e.t. The study has an important significance on the exploration and utilization of the agronomic characters genes of Mulberry germplasm resources, as well as the genetic breeding.