Studies on the Relationship between Heterosis and Gene Differential Expression Using Introgression Lines of Rice(Oryza sativa L.)
ZHANG Zhuan XUE Wei WANG Xiang-Kun SUN Chuan-Qing**(Department of Plant Genetics and Breeding,State Key Laboratory for Agrobiotechnology,Key Laboratory of Crop Genetic Improvement and Genome of Ministry of Agriculture,Beijing Key Laboratory of Crop Genomics and Genetic Improvement,China Agricultural University,Beijing 100094,China)
According to performance of F1 hybrids,in which the parents were derived from a set of introgression lines carrying variant introgressed segments from a japonica cultivar,Asominori,in the background of an indica cultivar,IR24,one high heterotic hybrid and one low heterotic hybrid were determined.Among the parents of these two hybrids,one parent was common,another parent hold less genetic differences.However,grain yield and its component evaluation on the high heterotic and the low heterotic hybrid showed that the heterotic hybrid mainly resulted from the increase of filled grains per panicle.Differential gene expression patterns during the panicle development stage were analyzed by cDNA-AFLP technique and 35 differential fragments were obtained.The differential fragments could be divided into four categories:expressing amount in the F1 exceeded or decreased than that in the parents,bands detected only in the F1 but neither of the parents,bands observed in both parents but not in the F1,and F1 bands presented in one parent but absented in the other parent.The proportions of which F1 bands presented in one parent but absented in the other parent were largest(about 83%),and of which F1 expressing amount exceeded or decreased than that in their parents were minimum(about 9%).The four differential category gene expression patterns were observed both in the high heterotic hybrid and the low heterotic hybrid,and the proportions were also similar.These results indicated there was no certain relationship between differential gene expression patterns and heterosis.Eight out of 35 differential expressed fragments were cloned and sequenced,then the sequences were landed on chromosomes and analyzed functionally respectively.It was found that two fragments were located on introgressed chromosome segments.Especially,one differential expressed fragment in the hybrid of high heterotic hybrid was located on the locus controlling the heterosis of grains per panicle.It seems that the information of the differential gene expression,genotypes of parents,heterotic locus and heterosis phenotype could be integrated.That will provide a base for constructing a technique flat which integrate the information of phenotype,genotype,QTL mapping,the expression of heterosis-related genes and the explaination of the molecular biological mechanism of heterosis in crops.
【CateGory Index】： S511
【CateGory Index】： S511