Gene expression in the leaves of super hybrid rice and identification of DNA markers for erect flag leaf

Two-line super hybrid rice gives 10–15% higher yield than conventional hybrid rice. The yield advantage of super hybrid rice is attributed to the uses of enhanced intersubspecific heterosis and improved plant morphology, which are the focuses of this thesis.; Physiological study showed that super hybrid rice Pei'ai 64S/E32 (PE) had a larger leaf area than its parents at the vegetative and reproductive stages. However, no heterosis in net photosynthesis rate was observed at the two stages investigated. At the vegetative stage, PE showed rapid leaf appearance rate and strong tillering ability, resembling the paternal line E32 and the maternal line Pei'ai 64S (PS), respectively.; Gene expression profiles in the vegetative and reproductive leaves of PS, E32 and PE were investigated at the transcriptional and translational levels by RAP-PCR (randomly arbitrary primed PCR) and 2-D gel electrophoresis. Various expression patterns existed in the hybrid rice leaf relative to the parents, suggesting changes of gene expression. Preliminary results showed that one group of differentially expressed genes, “one parental level”, accounted for 72% of differentially displayed transcripts at the vegetative stage. This type of expression pattern also constituted 44% and 64% of differentially expressed proteins at the vegetative stage and reproductive stage, respectively. Based on these analyses, complementarity of gene expression was proposed to explain the leaf heterosis of super hybrid rice. (Abstract shortened by UMI.)...