Analysis Of Genetic Diversity And Numerical Taxonomy Of Eggplant(Solanum Melongena L.) Germplasm Resources

Eggplant (Solanum melongena L.) originated from wild relatives which were native to India, and then came into China from South-East Asia. It had a long cultived history and very rich in germplasm resources in China, where it was recognized as secondary center of eggplant origin. Making an investigation of eggplant germplasm resources is a base of variety breeding. The morphological specificity of pollen is not easily affected by environmental condition, so it can be used for classification and deducing the trend of evolution. However, this method is not reported in eggplant by now. This study valuated some important morphological characters of the eggplant, which provide theoretical basis for the using of genetic diversity of eggplant germplasm resources. This study also provided sporopollen basis for eggplant classification through the observation to pollen morphology characteristics and the cluster analysis according to the principle of the numerical taxonomy.Genetic diversity analysis and principal component analysis were used to study29main traits of70eggplant germplasm resources. The results showed that there was different extent of diversity on the different varieties. As quantitative characters, the variation-coefficien of weight of single fruit was closed to60%, and that of fruit length and fruit diameter all about40%. It was found that the browning degree of eggplant had some relation to flesh color. The varieties of white flesh color are easier browned. The results of principal component analysis showed that10principal component factors, their cumulating contribution ratio reached to80.453%, which could be obtained from29morphological traits. The19traits which maximum load in the10principal component factors could reflect the most information of the plant characters.19morphological traits of36eggplant germplasm resources were studied and analyzed using cluster analysis, and the preliminary taxonomy was conducted based on pollen grains sizes which were observed used light microscope. The result from electron microscopic examination showed that the pollen morphology of34materials was single. They were all prolate and had3colporates, but there were difference on pollen grains sizes among different varieties. The materials were classfied into two clusters used both two cluster methods:cultivation groups and their related species. May be due to the influence of environmental conditions, the morphological traits cluster in cultivation groups is more disordered than that of sporopollen classification.Pollen morphology and exine ornamentation of28eggplant materials and their related species were examined under scanning electron microscope (SEM). The results showed that the pollen shape of all the materials were prolate. They all had3colporates which annularly distributed in equal space, and extended to the two poles. The sculptural type of eggplant was granulate. There were difference on pollen grains sizes and sculptural features among different varieties. Pollen grain size coule be as a basis to deduce the evolution among different shape of eggplant cultivars. The cluster analysis was conducted on some typical pollen morphology, and the results showed that the studied materials could be classified into two clusters: cultivars and their related species. The result was similar to that of traditional classification.