Mapping Of The QTL For Kernel Size In Maize

High and stable yield is the main purposes of crop cultivation and breeding research.The mapping of major QTL for maize kernel yield traits and genetic mechanisms are the effective ways to research the genetic control mechanisms of production and get the high-yielding corn.Chromosome single-segment substitution line(SSSL)is considered to be the ideal material for detecting and precisely mapping quantitative trait loci(QTLs)and gene cloning.Based on the preliminary findings,by using homozygous chromosome single segment substitution lines SSSL-Z22 as base material,a sets of F2:3 families was derived from a cross of SSSL-Z22×Zheng58,and a QTL of kernel width was mapped.The main results obtained in this article were concluded as follows:A gennetic map constructed with 34 SSR markers and spanned 25.6c M in length across target QTL.The average interval adjacent markers was 0.8c M in the gennetic map.F2:3 include 301 families from SSSL-Z22 × Zheng58 were the experimental materials.The QTLs of kernel width's and kernel thickness' s were located by 6 SSR markers(the order is P12-mmc0481-umc1680-phi087-P9-umc2201)in Bin 5.06,flanked by the SSR markers mmc0481-P9 and phi087-P9.Exploited 149 new molecular markers in the target segment for further narrow the target chromosome regions and narrowed the kernel width QTL qkw5-3 to 11.7c M interval between the SSR markers SYM036 and SYM128,its Physical map length is6.5 Mb and phenotypic contribution law is 29.9%.The results laid the foundation for the fine mapping of kernel size trait in maize,also provided a reference for research on genetic mechanism of grain yield trait and molecular breeding of grain yield.