Analyse Of Differentially Expressed Genes And The Relationship With Heterosis In Hybrid Rice

Heterosis is a common phenomenon in biological world. The main crops have used heterosis and achieved great success such as corn, rice etc. Current researches think that the different genetypes between the parents should be the foundation of heterosis in plants. Therefore people put forward that different genes which come form parents were combined together to form a new of network system, The heterosis of offspring is actually results come from different genes interaction. This study analyzed differentially expressed genes of three different intensity heterosis crosses which are high-heterosis crosses with Yangdao 6 as male parent, middle-heterosis crosses with Teqing as male parent, low-heterosis crosses with Minghui 63 as male parent by DDRT-PCR at three periods which are tillering stage,before heading and after heading in rice.The main results are as follows:1. Based on three different intensity heterosis crosses in three different developmental periods, the results of differentially expressed genes show that the proportion of all not expressed (UMONO) between progeny and parents is the highest for all combinations. This may be caused by the statistic methods. The proportion of all expressed (MONO) between progeny and parents is the second in three different developmental periods. These genes may be necessary for rice growth in all developmental periods. At the same time, with the growth of rice in different periods, the proportion of differentially expressed genes type is different. The dynamic view should also be taken into consideration in the study of heterosis.2. The variance analysis of data of yield charactes show that male and female parent all have impact on yield characters, but the influence of male parent to yield characters is larger than female. The variance analysis of differentially expressed types also show that the influence of male parent to differentially expressed types is larger than female. The results of correlation analysis indicated that male and female parent all have influence to the heterosis of offspring, but the influence of male is larger than female.The common expression between male parent and offspring or specific expression in male parent are advantage to heterosis. Therefore, selection of appropriate male parent has the vital significance in hybrid rice production.3. Part of differentially expressed genes are verified by reverse Southern. These fragments are sequenced and compared by NCBI for speculating their expression protein and possible function.The results show that differentially expressed genes are involved in many biological process, such as protein synthesis and degradation,energy and sugar metabolism, regulation of physiology reaction, signal transduction, DNA duplication, photosynthesis. Through the analysis of differentially expressed genes of Yangdao 6 in strength heterosis combination and other parents in weak heterosis combination, we speculated that the genes which involved in energy metabolism, protein synthesis and signal transduction may play an important role in the development of rice heterosis.The genes which expressed in weak advantage combination may play a negative effect in the development of rice heterosis.