Analysis Of Genetic Diversity With SSR And SRAP Markers In Eggplant (Solanum Melongena L.) Germplasm Resources

Eggplan（tSolanum melongena L.）is originated from the south Asian tropical region, Indian is accepted as the earliest domesticated place. Eggplant is cultivated for a long history in China, which recognized as secondary origin center of eggplant, and was riched in eggplant gerplasm resources. It is important to study on the genetic diversity of eggplant germplasm resources for the collection, conservation, identification, innovation and improvement program. In this study, the genetic diversity of 222 eggplant accessions originating from 13 regions of China, India and France of 35 foreign countries, were assessed using SSR and SRAP markers. The main results were as follows:1. Orthogonal design with four levels of five factors(Mg²⁺, Taq polymerase, dNTPs, primer and DNA template) was used to optimize the eggplant SSR reaction system. A suitable SSR-PCR reaction system of eggplant was established. The 10μL system contains: 10×Buffer 1.0μL, 25mmoL/L Mg²⁺ 1.5μL, 2.5mmoL/L dNTPs 0.8μL, 10μmoL/L primer 1.0μL, 50ng/μL templates DNA1.5μL, 5U/μL Taq polymerase 0.1μL, adding water 3.2μL.2. Genomic DNAs from 5 cultivation eggplants and 3 wild eggplants with different morphologies ware used to choose primers. Five primers with highly polymorphic and clear band were selected from 416 SSR primers, 25 primers with good repeatability and highly polymorphic were selected from 431 pairs of SRAP primers.3. Five paris of SSR and 25 paris of SRAP selected from screening were used to amplify 222 eggplant accessions. A total of 23 bands with high-definition and repeatability were produced using 5 SSR primers, with an average of 4.6 bands per primer combination. And 22 bands were polymorphic, with polymorphic rate 96%. Among them the polymorphism bands of cultivation eggplant produced was 65.2%. Two hundred and thirty nine bands with high-definition and repeatability were generated from 25 pairs of SRAP primers, with a mean of 9.6 bands per primer combination and with a polymorphic rate 100%. Among them the polymorphism bands of cultivation eggplant produced was 74.9%.4. Structure of population was analysed for the amplified result using Structure 2.1 software. The used accessions could be divided into five subgroups—S1,S2,S3,S4 and S5, including 31, 11, 66, 51 and 63 accessions, respectively. The division of subgroups is related to geographical origins of accessions. Most accessions in S1 subgroup are from Nigeria of Africa, most accessions in S2 subgroup are from Togo of Africa, most accessions in S3 subgroup are from China and India of Asia, most accessions in S4 subgroup are from Turkey of Asia, mose accessions in S5 subgroup are from China of Asia. The division of subgroups could not completely distinguish the fruit color and shape, but with some relations. The eggplant accessions with shallow green and white were distributed in the S1 and S3 subgroups, green eggplants were distributed in S2 subgroup, brunet eggplants （black and purple） were distributed in S3, S4 and S5 subgroups; the oblate shape eggplants were distributed in S1 and S2 subgroups, the accessions with fruit shapes of long barrel, ovale, long ovale and aphere are distributed in S3, S4 and S5 subgroups.5.Based on the result of dividing of Structure and the bands, a fingerprint map was obtained.