Study On Phenotypic Diversity And Construction Core Collection Of Bermudagrass

Bermudagrass is not only a important warm-season turgrass, but also a good forage grass which spread all of the world. There has abundant bermudagrass resource in China. The phenotypic diversity was studied and the core collection was constructed based on phenotypic characteristics with 626 bermudagrass germplasm cultivated in the turfgrass germplasm repository of the Institute of Botany, Jiangsu Province and Chinese Academy of Sciences. The results showed that:(1) abundant variation existed in these traits and the coefficients of variation of qualitative traits were higher than quantitative traits. There was great difference in diversity index of different traits and the diversity indexes of quantitative traits were higher than qualitative traits when analyzed the genetic variation of 626 bermudagrass germplasm based on 15 phenotypic characteristics.(2) There have significant correlations among some morphological characters of bermudagrass accessions. The general tendency is that the turf height is higher, the leaf is wider, the stolon is stronger, the reproductive stem height is higher, the number of inflorescence branch is more, the spikelet length is longer and the spikelet width is wider.(3) The result of main component analysis was showed that the accumulative contribution rate of the first 5 principal components was 72.05% which showed the contribution rate was disperse of these characters and the increase of accumulative contribution rate was not significant.(4) The optimal sampling method of constructing bermudagrass core collection was studied based on genetic distance, clustering methods and selection methods and sampling proportions. The optimal strategy constructing bermudagrass core collection is clustering accessions combined Mahalanobis distance with Complete linkage, selecting accessions with deviation sampling method under 30% sampling proportion. The bermudagrass core collection was established using this optimal strategy which consisted 190 resources. This core collection could represent the genetic diversity of whole germplasm and has important significant for the preservation, development and utilization of bermudagrass.