Studies On Physiological Characters Of High-yield Population Formation In Hybrid Rice

The researches on rice population began with 1950s in China, and many results were instructive value to rice breeding and cultivation. In order to prove up the regular patterns of high-yield population formation, the physiological characteristics of leaves, patterns of matters formation and evaluation indices for high-yield population component were studied by two hybrid rice II you58 and Liangyou pei9. Effects of physiological characters of roots and leaves after flowering and population construction regulation were also investigated in hybrid rice. Main results are as follows.Matter construction and its evaluation indices of high-yield population in hybrid rice Matter construction and its evaluation indices were analyzed in two hybrids rice II you58 and Liangyou pei9. The results showed that high percentage of productive panicles and more rational grain yield components were observed in high-yield population. The ratio of effective and efficient leaf area was distinguishable in different populations, but the indices of spikelet-leaf area and grain- leaf area were higher in high-yield population than the others. High-yield population had more dry matter accumulation from heading stage to mature stage, so the community growth rate (CGR) and relative growth rate (RGR) also were higher than those of the others after flowering. Single stem and sheath weight of high-yield populations was significantly higher than those of others, which caused the maximum transfer ratio and apparent transfer ratio of assimilate higher than those of others. Physiological construction of high-yield population in hybrid riceThe physiological characteristics of roots and leaves in three populations from hybrid rice II you58 and Liangyou pei9 after flowering stage were studied. The results showed there were no significant differences in the chlorophyll contents of flag leaf of differentpopulations at heading stage, but the high-yield population had significant higher chlorophyll contents than those of low-yield populations (A1B1 A2B1) on 30d after heading. The photosynthesis characters, such as net photosynthetic, rate stomata conductance, transpiration rate, intercellular CO2 concentration of flag leaf from high-yield population was also excelled low yield populations (A1B1 A2B1), which might result in yield superiority of the high-yield population. The photosynthesis physiological characteristics of low-density populations (A1B3 A2B3) were superior to those of the other populations, which showed that they (A1B3 A2B3) had strong physiological function of leaves.