优质籼稻育种中F_1代生理优势的研究

Studies on the Physiological Heterosis of F1 Hybrids in the Selectionof Fine Quality Indica Rice

对优质／优质、优质／非优质、非优质／非优质１０个不同籼稻组合杂种Ｆ１与其亲本植株生理特性进行了研究。结果表明：分蘖期Ｆ１植株叶片硝酸还原酶活性超中亲值，并与穗数呈正相关。始穗期Ｆ１植株剑叶叶绿素含量和光合速率超中亲值或近中亲值；呼吸速率低于中亲值或近中亲值；乙醇酸氧化酶活性超中亲值或低于中亲值，但以低于中亲值的组合居多。所有Ｆ１植株剑叶的呼吸速率和乙醇酸氧化酶活性都低于高亲值。试验结果还表明，七桂早／新丝苗、七桂早／早优占和七桂早／金占可以作为优质高产稻育种的最佳组合。

The physiological characters of F1 hybrids and their parents were studied in ten crosses of different mating types, i.e., quality/quality, quality/nonquality and nonquality/nonquality. The nitrate reductase activity of leaves in F1 hybrids at tillering stage was higher than the midparent value and had a positive correlation to panicles per plant. In flag leaves of F1 hybrids at initial heading stage, chlorophyll content and photosynthetic rate were higher than or similar to the midparent value, respiratory rate was lower than or similar to the midparent value, but glycolate oxidatase activity was higher or lower than the midparent value with more lower crosses. The respiratory rate and glycolate oxidatase activity of F1 hybrids were lower than those of higher parents. Qiguizao/Xinsimiao, Qiguizao/Zaoyouzhan and Qiguizao/Jinzhan can be used as the best crosses in the selection of fine quality and high yield rice.