Abstract: 【Objective】 The purpose of this study is to probe the mechanism of heterosis of Brassica napus in gene expression level, and to accumulate the experimental data for final demonstrating the genetic basis of heterosis.【Method】Two cDNA-based Arabidopisis microarrays were used to analyze gene differential expression in bud of an elite B.napus hybrid Huayouza6 and its parents.【Result】There were 83 over-expression transcripts and 331 under-expression transcripts between Huayouza6 and its female parent 8086A and 94 over-expression transcripts and 423 under-expression transcripts were demonstrated between Huayouza6 and its male parent 7-5. Further analysis showed that there were significant number of genes responsible for photosynthesis, which its implication for heterosis was discussed. Northern analysis of phosphoribulokinase coincided with its expression pattern derived from hybridization of Arabidopsis cDNA microarray and B. napus mRNA. 【Conclusion】This system of heterologous hybridization analysis should be applicable to other close relatives of Arabidopsis thaliana, and basic metabolism genes exert significant influence on heterosis of Brassica napus.

Key words: Brassica napus, Arabidopsis cDNA-based microarray, Huayouza6, Heterosis