[Differences of gene expression in bud stage of backcross hybrid between Ogura-type male-sterile Brassica napus L and B campestris L versus parents].

Crosses between female parent of Ogura male sterility Brassica napus L. and male parents of B. campestris ssp. chinensis Makino were made and F(1), BC(1) and BC(2) generations produced. Gene expression of two Chinese cabbage backcross hybrid BC(1), BC(2) and their parents at bud stage was analyzed by means of cDNA-AFLP technique. The results indicated that the patterns of gene expression differ significantly between BC(1) and BC(2) generations and their parents. There were many patterns of gene expression, including gene overexpression and gene silencing. Five patterns (seven kinds) of gene expression were observed, which include: (1) bands occurring in only one parent (two kinds); (2) bands observed in hybrids and one parent (two kinds); (3) bands occurring in only parents (one kind); (4) bands visualized in only hybrids (one kind); (5) bands observed in parents and hybrids (one kind). In accompany with the addition of backcross, the increase trend in backcross hybrids and their parents were described in the aspects of differential gene expression, bands expressed only in one parent and bands expressed only in both parents. The declined trend in backcross hybrids and their parents were observed in the aspects of bands expressed in both hybrids and one parent (two kinds), bands visualized in only hybrids and bands observed in parents and hybrid. Fifteen patterns of gene expression were observed in F(1)bBC(1)bBC(2) and backcross parents. The percent of bands expressed in F(1)bBC(1)bBC(2) and backcross was highest.