Gene Mapping Of Non-lateral-branch Gene Nlb In Cucumis Sativus. And Cluster Analysis Of Genetic Diversity Of Petunia Hybrida Vilm By ISSR

Cucumber (Cucumis sativus L.) is widely cultivated all over the world. Cucumber cultivation area is very large in China, too. Cucumber production enormously impacts the country's annual supply of vegetable, so it is important and urgent to research cucumber's traits. The branch is a basic characteristics of plants,occupying a crucial position in the morphological structure. The number of lateral branch of cucumber influences crop yield by planting density, number of fruit per plant, pest control, management costs, so to control the lateral branch is an important part of crop genetics and breeding.In this study, with the SSR molecular markers and bulked segregant analysis, the F2 generation of non-lateral-branching line S61 and branching line S06 were used as materials to map the nlb (non-lateral-branch) gene of cucumber. Finally, two SSR molecular markers, SSR12070 and SSR10134, were located at the same side of nlb, and the SSR molecular marker CMBR40 was at the other side. The genetic distance between nlb and SSR12070 was 26.3cM, between nlb and SSR10134 was 29.2cM.In order to reveal the genetic diversity and better apply for breeding, Inter-Simple Sequence Repeat(ISSR) molecular markers were used to detect the genetic diversity in 142 varieties of Petunia hybrida Vilm. Seventeen ISSR primers were selected for ISSR-PCR, and amplified, a total of 142 polymorphic bands, average 7.8 polymorphic bands per primer, polymorphism-strip ratio is 82.5%. The genetic similarity coefficient between material in 0.4015～0.9318 range, showed the P. hybrida has a wealth of genetic diversity. The software calculation results showed that 142 P. hybrida varieties average effective Numbers of alleles for 1.6535±0.2853, Nei genes diversity index an average of 0.3744±0.1236, and the average Shannon information diversity index of0.5526±0.1486. The clustering results showed it was in certain correlation with color, pattern, plant type, varieties comparison of source. The results could establish molecular theoretical basis for the breeding of P. hybrida.