Photosynthetic characteristics and yields of new plant type rice and hybrid rice at grain-filling stage
HUANG Jinwen, LIANG Yiyuan, LIANG Kangjin, LIN Wenxiong (College of Crop Science, Fujian Agriculture and Forestry University, Fuzhou, Fujian 350002, China)
Three different rice cultivars, characterized by a larger panicle type, such as new plant type rice IR6560085, twoline cross Peiai64S/E32 and threeline cross Eryou86 were used for the experiment to investigate the comparative properties of the production and the partitioning of the dry matter and its relationship with the grain yield during the grainfilling stage. The results indicated that: there was no significant difference in the yields between Peiai64S/E32 and Ⅱyou86, but the yield of the two cultivars was significantly higher than that of IR6560085 respectively. As far as the production capability of single stem was concerned, the new plant type had a wellorganized plant appearance, showing its less tillers, larger panicles,higher rate of available panicles,heavier weight of single stemsheath and higher rate of photosyntheses, which were attributed to its high biologic yield, but the transportation of carbon reserves in the leafstemsheath of IR6560085 was inhibited in late stage of the grainfilling, resulting in metabolic disorder and imbalance of carbonnitrogen in the functional leaves,in turn led to decreased nitrate reductase activity in the leaves, consequently reduced percentage of filled grains and yield and hindered the realization of the yield potential of the rice cultivar.