Genotypic Difference on Rice Ratooning Relating to Stubble Height

Rice ratooning in relation to its variety and stubble height was studied.One hundred ninety two cultivars that are widely used in practice in the country and two stubble heights(i.e.,5cm.and 40cm)were the variables included for the study.The results indicated that the ratooning of the high stubble rice(40cm)was significantly greater than its counterpart(5cm).And,for different varieties of rice,the stubble height affected the ratooning differently.For instance,most of the japonica varieties were found to be suitable for the low stubble treatment, whereas the indica rices were better fitted for the high stubble treatment.In this study,some of the varieties,such as Shaoniejing,Taipei 309,Yongyou 6and R402-10,showed a strong ability of ratooning.The results provided not only the germplasm resource available for breeding,but also rich information for future studies of genetic and physiological mechanisms on rice ratiooning.