Suitable nitrogen fertilization mode for high yield and quality and high N use efficiency in high density direct-sown rapeseed(Brassica napus L.) Effect of Chitosan Coating on Seed Germination and Salt-tolerance of Brassica napus L. Genetic Analysis for Lysine Content of Rapeseed Cake (Brassic napus L.) at Different Periods after Anthesis Correlation between Canopy Spectral Vegetation Index and Leaf Stomatal Conductance in Rapeseed(Brassica napus L.) Metabolism of Polyamine during the Development of Flora Buds in Cytoplasmic Male Sterile Line and Its Maintainer Line in Brassica na pus L. Cloning of Citrate Synthase Gene in Rapeseed(Brassica napus L.) and Its Expression under Stresses Changes of RNase Vitality in the Anther Abortion Processes of Several Male Sterile Lines in Rapeseed (Brassica napus L.)