水稻光合效率的杂种优势及其与产量构成因素的遗传相关

The Genetic Correlation Between Yield Components and Heterosis of Rice Photosynthetic Efficiency

作者以汕优2号等六个杂交组合及其亲本为材料,研究了水稻光合效率的杂种优势及其与产量构成因素的遗传相关。结果表明:(1)水稻光合速率杂种优势前期不明显,直至抽穗以后优势始变明显,显示出剑叶净光合速率高,杂种优势强,下位叶光合速率低。杂种优势弱;(2)分蘖期净光合速率遗传力小,受环境影响较大,抽穗成熟期剑叶的净光合速率遗传力大,受环境影响较小;(3)分蘖期下位叶净光合速率与株高、有效穗、穗粒数、穗密度遗传相关性较大,抽穗成熟期剑叶的净光合速率则与穗重、有效穗、结实率、穗密度遗传相关较大,但不同时期净光合效率与产量的遗传相关都不明显。

The yield components and heterosis of net photosynthetic rate in six hybrid rice combinations and their parents were studied in the paper. Results obtained were as follows: i). Heterosis of net photosynthetic rate was not observed until the earing stage, by then, the net photosynthetic rate and heterosis of the flag leaf were higher than those of other leaves. ii). Heritability of net photosynthetic rate was low at tillering stage, which was greatly affected by environmental factors; while that of the flag leaf was high at earing and maturity stage, which was not much affected by environmental factors in contrast, iii). Genetic correlation of the net photosynthetic rate at tillering stage was relatively high with yield components such as number of effective heads, plant height, number of grains per head, and head density; whereas the genetic correlation at earing and maturity stage was high with characters as weight of head, number of effective heads, setting percentage, and head density , etc. However, the genetic correlation between the net photosynthetic rate and the yield of hybrid rice was not evident in various stages.