小白菜（Brassica chinensis L. var. chinensis）種原園藝特性遺傳歧異研究

Abstract

The experiment was to study the morphological diversity of B. chinensis L. var. chinensis accessions, and evaluated their horticultural traits in order to know the potential use of the local accessions incorporated to breeding programs in the future. Thirty-five accessions were either local landraces or obtained from farmers in the western Taiwan. Genetic diversity based on morphological traits showed a high level of variation among accessions. Higher polymorphism was exhibited in growth vigor and leaf surface, while lower polymorphism in leaf margins and leaf hairiness. Cluster and principal component analyses based on horticultural traits were to obtain information on the usefulness of the traits and to determine relationships among them. Cluster analysis displayed a wide range of diversity for traits, and pooled accessions of similar characteristics in a same cluster. Principal component analysis showed that the first two principal components accounted for 63.9% of the variability among the 35 accessions and was associated with plant leaf, petiole and shoots fresh weight, leaf length, leaf area and petiole width, and leaf colors. The first two principal components were plotted to observe the relationships among the accessions. In subgroup A-1, TYC37 and TYC38 on the top of the plot could be utilized in hybridization program to develop high plant fresh weight and lighter leaf color. However, deeper green leaf, thinner leaf and stem need to be combined with some accessions for lighter green leaf color, thicker leaf, longer petiole, and larger petiole diameter, to develop elite cultivars.