Response Mechanism Of Different Waterlogging Tolerance In Rapeseed (Brassica Napus L.)

The forty-four rapeseed (Brassica. napus L.) germplasm were selected randomly to test the waterlogging tolerance relative characteristics during seed germination in the anoxic condition. The results showed that the germinated seed in anoxic condition for 12h, the seedlings were reduced significantly in root, weight, length, survivor rate. The analysis of correlation showed that vigor index can roundly evaluate the faculty of growing up in waterlogging tolerance and the electric conductivity may the ealy filtering index. Among 44 lines of rapeseed, there were extensive variation in waterlogging tolerant relative characteristics and vigor index was normal school. The lines of 03P79-1, 03P62-5 , Zhongshuang No. 8 and Zhongshuang No. 9 were the waterlogging tolerance group with higher relative characteristics and the lines of 03P63-1, 03P165-2 and GH01 with lower relative characteristics and they could be used as breeding resources.Nine rapeseeds known for their reactions to waterlogging stress were used in this study and some stumpy characters, physiological characters, seed yield and quality responses of different waterlogging tolerant were investigated after flowering stage waterlogging (FW) for 10d. The waterlogging stress severely affected growth, yield components and quality in all rapeseeds through significant increase of withering index, relative electrical conductance (EC), malnodialdehyde (MDA), No. adventitious root, position of primary branches, 1000-seed weight and protein content, significant reduction of field root oxidizability, plant height, shoot width, survivor rate, harvest index and oil content. While the tolerant rapeseeds showed many significant differences responses compared with susceptible rapeseeds. After 10d waterlogging stress, the tolerant rapeseeds could endured anoxia stress by significantly increase more adventitious roots, but less reduction in plant height, shoot width, dry weight, root oxidizability, EC, MDA, withering index and field survivor rate. The yield components indicated that the tolerant rapeseeds increased the 1000-seed weight significantly, less reduction in No. primary branches, plant pods and pod seed, and resulted in significant less reduction in biomass, seed yield per plant and plot yield. The oil content of susceptible rapeseeds decreased but protein content increased significantly, while tolerant rapeseeds could keep similar quality to controls. The lines of Zhongshuang No. 8 and Zhongshuang No. 9 were the higher relative characteristics and the entent of output reduction in seed yield per plant was lower markedly, but the quality characteristics were no obvious change. The lines of GH01, 03P147-1 and 03P33-4 were the lower relative characteristics.The Analysis of correlation there were significant correlationship between tolerant characteristics of germinating seed and spring field waterlogging stress, indicated germinating seed anoxic stress could predict the yield waterlogging tolerant in field stress. The seed yield per plant was decided by shoot width, No. adventitious root, root dry weight, withering index, EC, root oxidizability, MDA, 1000-seed weight, No. seeds per pod and pods length.