Study on the Methods of Constructing Chinese Cabbage Core Germplasm Based on the Morphological Data Construction Core Collections of Pear Germplasms in Cold Region by SSR and Phenotypic Traits Genetic Diversity Analysis of Seedingand Early Flowering Stage Morphological Marker in Cucumber Core Germplasm Advances on genetic diversity of cotton (Gossypium) Construction Core Collections of Pear Germplasms in Cold Region by SSR and Phenotypic Traits Studies on the Constructing of Pepper Core Collection Based on Phenotypic Data Study on the Methods of Constructing Chinese Cabbage Core Germplasm Based on the Morphological Data