Molecular Marker-Assisted Backcross Breeding Of Maize Restorer Line And Its Efficient Analysis

We develop, in this research, the MAS research of the two populations BC1F1 and BC2F1 that came from different parents on the basis of the fine position of the Rf3 gene. The results of the MAS research in the population are as following.1) Seventy-one polymorphic markers , including 59 SSR markers and 12 AFLP markers, are used, in the MAS of HSBC1F1 population. 82 polymorphic markers including 55 SSR, 24 AFLP and 3 RAPD markers are applied in the MAS of MYBC2F1 population.2) The strongest background resemblance of the individual genetic background to the recurrent parent's is 83.9% by means of one MAS generation in the HSBC1F1 population, about 0.6348 generation genetic gains is obtained than the theoretical value without selection. The linkage lag at one flank had been limited to less than 8. 9cM. In MYBC2F1 population the strongest resemblance of the individual genetic background to the recurrent parent's has come to 92% by one PS and one MAS, 0.6349 generation of genetic gains obtained.3) By non-linear regressive analysis of the markers and the coefficients of variation of back ratio of genetic background, we find that the coefficients of variation in BC1F1generation is always larger than that in BC2F1 generation, and background selection efficiency will decrease gradually as the genetic generation increase. The coefficients of variation drops slow more and more as the number of markers increased. It shows that the selection that apply a small quantity of markers have the similar effect of the selection that apply a large quantity of markers.4) we find that the simple correlations among the back ratios of genetic background are significant comparatively, so we put forward a method of progressive selection based on thefindings , and hope to select the interesting strains or lines rapidly, accurately and efficiently.5) The correlation of the results of the PS and MAS are not significant (P>0. 05) in the two populations.6) By the analysis of partial correlation of experiment data that came from two populations, we find that the correlation of the back ratio of genetic background between chromosomes and genome is very significant (P<0.01). To apply the polymorphic markers to scan one or more chromosomes, we also can select precisely the individuals with high back ratio of genetic background.