Abstract: Hybrid rice ( Oryza sativa L. ) seedling is more vigorous in root development and plant growth than its parental lines in the tested indica rice of hybridized combination (Shanyou 63 (Fl): Zhenshan 97A × ♂Minghui 63). Analysis of the difference in gene expression between the hybrid Fl and its parental seedlings by means of mRNA differential display indicated that gene expression of the parental lines was obviously altered the hybrid Fl both in quantity and quality., Quantitatively, there were over-expression and under-expression of genes in hybrid Fl with genetic expression trend forwards a single parent. Qualititatively, hybrid Fl could have specific gene expression, single parem (maternal or paternal) gene silence, co-suppression of paternal genes, and single paternal gene expression. The relationship between heterosis formation and alteration of gene expression of parental lines in hybrid Fl was also discussed.

Key words: Gene expression, mRNA differential display, Heterosis, Rice