Study on C/N metabolism characteristics in yellow-seed rapeseed (Brassica napus L.) during seedling stage

摘要

Yellow-seed rapeseed (Brassica napus L.) is characterized with thinner seed coat and lower hull percentage, which in turn is correlated with higher oil, protein and lower crude fiber contents compared to black-seed rapeseed from the same genetic background. The breeding of yellow-seed rapeseed has become one of the main objectives in rapeseed breeding. However the growth vigor and yield of yellow-seed rapeseed were not good as black-seed rapeseed. The growth vigor of rapeseed plants during seedling stage is in connection with its yield significantly. Two pairs of different genetic near-isogenic lines of black-seed and yellow-seed rapeseed (Brassica napus L.) genotypes were used to study the physiological characters of yellow-seed rapeseed in seedling stage, which mainly included photosynthetic characters and characters on C/N metabolism. The results showed that there were higher sugar content and lower protein content, nitrogen content and activity of nitrate reductase in yellow-seed rapeseed plants than in black-seed rapeseed plants regardless of various development stages or various plant organs. It was discovered that chlorophyll content and carotenoid content of yellow-seed rapeseed were lower than those of black-seed rapeseed, and their net photosynthetic rate was also lower compared to black-seed rapeseed from the same genetic background.