Abstract:

The ratooning rice is the secondary rice, which sprouted from the rice pile axillary after the hybrid mid-season rice was harvested. It is suitable local effective cultivation pattern which was used fully light hot resources of idle period in autumn and increased output, and it was the bigger application area in south rice area. The ratooning rice research beginning from 20th century 30’s, at present up to, the research content was mainly concentrated in the cultivation and the physiological aspect, but the correlation research about the ratooning ability and agronomic trait of the main crop was less, lacking of the consistent conclusion. Mid-season hybrid rice was regard as reserving ratooning rice at present in china, but the correlation study of ratooning ability of mid-season hybrid rice and its agronomic traits of main crop was rarefaction, being short of unanimous conclusion. In order to choose strong ratooning ability hybrid rice combination, the relationship between the ratooning ability and agronomic traits of main crop with 229 mid-season hybrid rice combinations were tested in 1996, 1999 and 2001. The results from both correlation analysis and path analysis showed that: ⑴ the stem-sheath dry weight of main crop had maximum direct effect on ratooning ability, the correlation coefficient between the above two traits was significantly positive, and the regression equation had better expecting function, indicating that stem-sheath dry weight was an important index to measure the ratooning ability of hybrid rice combination; ⑵ the correlation between the ratooning ability and the amount of effective panicles which has strong effect on field group ecology, was not significant, but the partial correlation was significant, showing it was the important trait of influencing ratooning ability; ⑶ the effects of plant height, flag leaf length, grains per panicle, grain weight per panicle and growth duration, which were negatively correlated to the ratooning ability, and the tillering ability, which was positively correlated to the ratooning ability, were different in 3 experiments, showing the influence of the traits to be unstable to the ratooning ability.

Key words: Mid-season hybrid rice, Ratooning ability, Agronomic traits, Correlation