一个新水稻内卷叶突变体的杂优组合生物学效应

Biological Effects in Heterosis Combination of Novel Adaxially-rolled Character in Rice( Oryza sativa L. )

以生育中后期叶片适度内卷叶和平展叶组合为材料,研究了水稻适度内卷叶突变体RL(t)杂优组合的生物学效应。结果表明:1RL(t)杂优组合与平展叶组合生育前期生长叶态相似,均为平展叶且叶基角较大;2RL(t)杂优组合生育中后期叶片气孔导度、胞间CO2浓度、蒸腾速率显著高于平展叶组合,其光合速率较平展叶组合也有所提高,为其提高单位面积产量奠定了基础;3RL(t)杂优组合在群体中部透光率显著高于平展叶组合,改善了群体中下部叶片受光条件,从而提高了光能利用率;4RL(t)杂优组合在不同密度下产量构成因子自我调控能力显著增强,尤其在高密度下,具有较高的容穗量,并能较好地保持大穗特点。本研究为适度内卷叶应用于水稻高产育种提供理论依据。

Taken the flat leaf heterosis combination of rice at middle and later periods as tested materials,the biological effects of the heterosis combination of the moderate rolling leaf mutant RL（ t） were studied. The results showed that（ i） There was not insignificant difference of the leaf morphological characteristics between the RL（ t） and the flat leaf heterosis combination at early growing stage,and both had flat leaves and relatively big basic leaf angles.（ ii） The stomatal conductance,the intercellular CO2 concentration,transpiration rate and photosynthetic rate of the upper three leaves of the heterosis combination of the RL（ t） were significantly higher than that of heterosis combination of flat leaf at middle and later periods,which laid foundation for increasing the yield per unit area.（ iii） The light transmittance of RL（ t） in population at the middle part leaves was higher,which improved the illumination and photosynthesis of its middle-low leaves of population and increased the efficiency of solar energy utilization.（ iv） This research revealed that the heterosis combination of the RL（ t） could not only hold a larger amount of the valid panicles but also demonstrate large-panicle features,especially in high-density condition,and also the ability of its adjusting control to yield and components were significantly increased under different densities. This study would provide a theoretical basis for the principle of high-yielding breeding with the application of the moderate rolling leaf mutant in rice.