Evaluating Biodiversity Of Potato Germplasms Via SSR Marker Based Genetic Analysis System

Potato is a very important food and vegetable crop with increasing importance in agriculture. Wild diploid potato species contain many excellent characters such as resistances to biotic/abiotic tresses and adaptability to divers envrionments which are absent in modern cultivars. It is improtant to construct a reliable genetic evaluation system for widely usage of germplasms in genetic research. In this study, the genetic diversities of 87 diploids and 7 triploids potato species were evaluated by SSR markers and morphologic assessments. The major results are as follows.The variation coefficient of 39 morphologic characters varied from 0.20 to 1.76, and the color of tuber bud had the highest variation coefficient while the shape of stipule had the least one.79 potato clones were classified into 4 groups at 16.415 euclidean distance by UPGMA clustering using 39 morphologic characters.According to SSR analysis, there are 33 SSRs amplified well in the 59 SSRs chosen initially, and total 249 allelic bands had been amplified with a 99.2% polymorphic ratio and an average 0.71 PIC value. According to the resulst of UPGMA clustering, The 23 SSR markers seated at 12 chromosomes could construct the genetic evaluation system for 94 potato germplasms.Based on SSR analysis and UPGMA cluster, the 94 potato germplasms were classified into 8 groups at 0.684 coefficients. The first group included hybrids of phu-stn, the second group was more complex, included diploid and triploid clones, the third group contained offspings of 08981-01 and 08661-02, the forth group included hybrids of phureja, the genetic backgrouds of the fifth and sixth groups were more distant, the seventh group contained hybrids of AC143 and tar PI414150, the eighth group included wild species and their progenies form cell fusion. The results of clustering by SSRs were consisted with morphologic assessment.According to the gray relation coefficient analysis, a lot of high-yield clones, excellent quality for processing clones were screened out for further genetic breeding.