Cloning,Characterization and Real-time RT-PCR Analysis of a Key Gene beta-Amyrin synthase for Saponin Biosynthesis in Barbarea vulgaris Cloning,Characterization and Real-time RT-PCR Analysis of a Key Gene beta-Amyrin synthase for Saponin Biosynthesis in Barbarea vulgaris Advances on Research and Utilization of Elite Resistant Resource–Barbarea vulgaris Advances on Research and Utilization of Elite Resistant Resource–Barbarea vulgaris Effects of Barbarea vulgaris on the development and oviposition preference of Plutella xylostella Analysis on Genetic Diversity of Barbarea Vulgaris Germplasm Resources Based on Phenotypic Traits The effects of volatiles from Barbarea vulgaris plants on choice response of Plutella xylostella female moths