不同发育时期水稻强、弱势粒灌浆速率的遗传分析

 【目的】对不同发育时期水稻强、弱势粒灌浆速率的遗传效应表达进行研究。【方法】以5个水稻品种组配的2×3不完全双列杂交为试材，应用包括胚乳效应、细胞质效应、母体效应的三倍体胚乳模型及条件遗传方差分量分析方法进行分析。【结果】（1）条件方差分析方法能检出一些非条件方差分析方法不能检出的方差分量。（2）条件方差结果证明：Ⅰ.强势粒灌浆速率表达主要受遗传因素控制。前期以胚乳效应为主，中、后期以细胞质效应、母体效应为主。从基因效应的性质看，前期以胚乳加性方差为主。母体加性方差在整个灌浆期间都有显著的表达。Ⅱ.弱势粒的灌浆速率在前期、后期易受环境影响，前期以胚乳加性×环境互作效应为主，后期以细胞质×环境互作效应为主。仅在中期以遗传因素为主，此时胚乳加性、母体加性方差均显著，但以胚乳效应为主。【结论】强、弱势粒灌浆速率应根据籽粒胚乳加性方差，分别在灌浆的前期、中期进行选择。后期提高母体植株的光合效率可能对弱势粒的灌浆有帮助。

Genetic Analysis of Grain Filling Rate in Different Growth Stages of Superior and Inferior Grains in Rice

Zhu`s genetic model of endosperm characters and statistical approaches of conditional genetic variances were used to analyze the genetic regulations of grain-filling rate for inferior and superior grains of rice including three NPT sterile lines and two restoring lines with NC-Ⅱdesign. The results showed that for the superior grains, VG was the main variance component, highest in the early stage. Endosperm effect was the major form in the early stage, and cytoplasmic and maternal effects were more important in the middle and late stages. The active time for each conditional variance component was VA（t∣t-1）in the early and middle stages, VC（t∣t-1） in the middle and late stages , VAm（t∣t-1） in the whole filling stage and VDm（t∣t-1） mainly in the early stage. For the inferior grains, only in the middle stage VG was more than VGE, and the main variance component was also from endosperm variances. This result indicated that the inferior grains were more likely to be influenced by environments. The expressing characters of gene effects were? VD（t∣t-1） and VAm（t∣t-1））expressing significantly in the early stage and VAm（t∣t-1） being more important; VAm（t∣t-1） being less than VAmE（t∣t-1）. In the middle stage , VA（t∣t-1）became the most important variance and VAm（t∣t-1）was the second. In the late stage VCE（t∣t-1）became the main variance component. The results between conditional variance analysis and variances analysis of inferior grains were conflicting.