Screening and evaluation of waterlogging tolerance in Brassica germplasm resources

To fully understand Brassica germplasm of waterlogging tolerance,270 rapeseed materials from rapeseed industrial systems were evaluated for waterlogging tolerance based on relative survival rate( RSR) at germination stage after 12 h of waterlogging. The results demonstrated rich genetic diversity of waterlogging tolerance,and the tolerance varied evidently among different types of varieties. The waterlogging tolerance of Brassica rapa was much stronger than that of Brassica napus. Varieties of rapeseed in downstream region of Yangtze River were more tolerant than those in upstream and midstream regions,and the tolerance was not significant between varieties of upstream and midstream regions. Waterlogging tolerance of spring rapeseeds was stronger than those of winter and semi- winter rapeseeds. Compared to hybrid rapeseeds,conventional rapeseeds showed better tolerance to waterlogging. Based on this study,waterlogging breeding lines could be selected according to specific environments and growth periods.