Photosynthetic Rate Of Rice Germplasm Resources And Combining Ability Of Photosynthetic, Yield And Quality Characters

The research on photosynthetic rate of rice germplasm resources and combining ability of photosynthetic , yield and quality characters is a basic one on rice super-high yield breeding.In this study, the measurement of 117 rice germplasm resources with LI-6400 photosynthetic instrument at different growing stages indicated that the net photosynthetic rate (Pn) from initial heading to full heading stage was stable, which could be applied to the comparison between different germplasm resources in terms of their photosythetic rate. The result showed that different rice varieties presented significant difference in their photosynthetic rates. The photosynthetic rate showed a nomal distribution skewed. According to the results of clustering analysis, 117 rice varieties were classified into five groups, i.e. very high, high, middle high, middle low, and low of Pn. The photosynthetic rates were close to or higher than 25μmol/( m~2 ? s) in 14 germplasm resources, which amounted to 11.97% of the total materials tested, including Indica rice Ainanzao, Teqing, Fulidao, Ai50, Ketan Bajong, etc; Japonica rice Longdao, Longken46 and Daoshaguang; and Oryza glaberrima Steud Rico-1. The results of the research on the relationship between agronomic characters and photosynthetic rate showed that the resources with high photosynthetic rate had such characteristics as green or dark green leaves, middle erective or nearly erective flag leaves and moderate loose plant type.Fourteen parents of three-line indica rice, including 10 sterile lines and 4 restoring lines were chosen and analyzed in terms of the combining ability of 5 photosynthetic, 7 yield, 8 quality characters with pXq incomplete...