Abstract:

Rice variety with different low-light-resistant ability had different response against light. So low-light-resistant rice could be screened from a large number of germplasm resources of rice varieties resistant to low light quickly and effectively, and then the selection efficiency was promoted. 61 rice varieties (inbreed lines) with different genes were treated by shading at seedling stage. The change of leaf age, seedling height, root length, shoot dry weight, root dry weight, root-shoot ratio, root volume, chlorophyll content (SPAD) and total dry weight per plant were studied. Correlation analysis and path analysis of 9 characters were carried out too. The results showed that chlorophyll content of all varieties was increased by 55% shading. Seedling height of some varieties were improved, the others were dropped. Most varieties of root length, leaf age, root volume, root dry weight decreased at different degrees, a few varieties were increased. Shoot dry weight and total dry weight per plant of all varieties decreased at different extents. Moreover, the direct path coefficient that the relative index of shoot dry weight, root dry weight and root length to total dry weight per plant under low light environment were 0.7593, 0.2105 and 0.0346, respectively, and the correlation coefficients were 0.9034, 0.7634 and 0.6862, respectively. It was suggested that the relative index of shoot dry weight under low light environment might be used as believable indicator to identify the low light tolerance of rice, and the relative index of root dry weight and root length under low light environment could be used as assistant indicator.