Abstract: Technique ofdirect-seeding rape in no-tillage rice stubble field can decrease the labor and reduce the area of winter fallow fields, but its output is often less than the tillage cultivation model. In order to investigate the production constraints of direct-seeding rape in no-tillage field, we designed a pot experiment to determine physiological indexes of all lines such as root-shoot ratio, drought resistance, waterlogging tolerance and agronomy nitrogen use efficiency at seedling stage, and designed a field trial to determine the yield loss ratio of 15 lines in the no-tillage mode, then compared the relationship between physiological indexes at seedling stage and yield loss ratio in no-tillage mode. The result showed that, (1) differences in characters at mature period, yield and its components for the same rapeseed line in different cultivation modes depended on differentlines, (2) compared with that in the tillage mode，the lines that had small drop in shoot dry weight, economic coefficient or 1000-seed weight in no-tillage cultivation also had small yield loss ratio, (3) yield loss ratio at direct-seeding rape in no-tillage rice stubble field negatively correlated with root-shoot ratio, drought resistance and waterlogging tolerance at seedling stage, but positively correlated with nitrogen use efficiency at seedling stage, (4) the lines that had big root-shoot ratio, good drought resistance and waterlogging tolerance and robust seedling growth should be selected in the course of the cultivation and management, prevention against drought and waterlogging and balanced fertilization could improve production efficiency of direct-seeding rape in no-tillage rice stubble field.

Key words: Rapeseed, No-tillage paddy rice field, Direct planting, Yield loss