The Background Selection Research Of Maize Sterile Lines Backcross Breeding By SSR Markers

Maize hybrids seed production is an important guarantee of the field production and maize unit yield. However, artificial emasculation increased cost and could not ensure the quality of the seed. Therefore, it was an effective means for breeding sterile line and sterile line seed breeding. In this study, male sterile cytoplasm He344and inbred line Fu63018were respectively used as donor and recurrent parent to produce backcross populations on BC1F1and BC2F1population. A total of60markers that cover10chromosomes of maize and show well polymorphism between the parents were used to analysis genetic background of recurrent parent, which aim to explore the suitable number of markers and the way of selection using MAS to backcross. The main results are as follows:1. The Statistical analysis of phenotypic traits showed that tassel primary branch numbers possessed obvious differences among12agronomic characters of the two parents. The results of variation coefficient showed that bald head length and axis diameter displayed maximum and minimum in the two populations, respectively. The correlation analysis showed that most of characters showed varying degrees relevance. The similarity analysis of recurrent parent discovered that a total of20had higher similarity with recurrent parent in86BC1populations,29in63BC2populations.2. The analysis of polymorphic SSR markers showed that a total of60markers displayed well polymorphic, and which covered10chromosomes of maize, at least3makers in every chromosome.3. The analysis of genetic background showed that the proportion of recurrent parent genome (PRPG) was74.41%in86BC1populations, and the highest was up to85%. The average PRPG was87.36%in63BC2plants and the highest was up to97.5%. In addition, the average PRPG of150BC1F1population was74.17%, and one individual accessed to87.5%, accounted for0.67%in analyzed populations; the average PRPG of150BC2populations was86.48%,12individual plants accessed to93.75%, accounted for8%in analyzed populations4. The comparison of differences between phenotypic selection and molecular marker-assisted selection results showed that a total of23highest PRPG among86BC1populations,9had higher similarity in agronomic character, accounted for39.13%. In addition, a total of14highest...