Development Of Chromosome Segment Substitution Lines With H21Genetic Background And QTL Mapping For Yield Related Traits In Maize

Due to the simple genetic background and accuracy mapping QTL and good stability,Chromosome segment substitution lines are the best material choice for mapping quantitative trait loci.Basing on the preliminary studied of the labortatory, we produced BC7F1population using H21as recipient parent and NX531as the donor parent by backcrossing and crossing approach.Combining with SSR molecular markers assist selection (MAS), we futher builded chromosome segment substitution lines with high percentage of recipient parent by backcrossing and selfing. Ultimately we chose140lines consisting of chromosome segment substitution lines groups HNCSSLs. As well as, quantitative trait locus (QTL) for yield related traits in maize were identified based on the field phenotype analysis from HNCSSLs. The results were mainly listed as following.1. We analysied genotype of539plant of BC7F1by176SSR markers,539plant containing2109donor fragment from the NX531, with an average of3.9. Based on IBM2008neighbors reference map, the total length94314.03cM of the donor fragment, the length minimum10cM of donor fragment, with the longest of975cM, with the average of44.7cM. All donor fragment covered about76%genome of recurrent parent;the PRG was higher98%more than80%plant;241plant (44.7%) contained several donor fragments1-2, with only20plant (3.7%) contained donor fragments more than10.2. Considering factor for PRG and fragment size, with the number of fragments,140plant of BC7F1were chosen to inbreed. Combining with SSR molecular markers assist selection of target fragment, we finally developed the140lines of homozygosis of target fragment composed of chromosome fragments substitution lines HNCSSLs. The HNCSSLs total containing250donor fragment, The first chromosome up to52and the fourth chromosome at least11number of donor fragment. Wherein the donor fragment is from1to2ratio of78.5%, and only a line contained donor fragment is8, with the average of1.8of per substitution lines. The PRG of HNCSSLs ranged from97.7%to99.7%, with the average of99.4%. All donor fragment of HNCSSLs which we construction covered about68.5%genome of recurrent parent.3. As HNCSSLs mapping population,A total of14QTLs include7QTLs for KRN,3QTLs for EL and2QTLs for CW and2QTLs for100-KW were identified, single QTL for KRN explained3.63%-9.85%phenotypic variation and the additive effects of variation range from-1.35to1.97row; single QTL for EL explained5.56%-10.90%phenotypic variation with the additive effects of variation range from-1.24to1.63cm. Nearly markers umc2011and umc2077as QTL-rich regions owing to many QTLs for KRN,EL and100-KW were detected. In HNCSSLs, some substitution lines can be significantly improved since import donor fragment on the KRN,a tatal of89lines (64%) higer than the H21on the KRN,the highest nearly by16rows, substitution lines which improved on the KRN can be directly used for corn breeding...