A genome scan for quantitative trait loci affecting grain yield and its components of maize both in single-and two-locus levels

查看全文 作　　者：YAN [1,2]Jianbing;TANG [2]Hua;HUANG [2]Yiqin;ZHENG [2]Yonglian;SUBHASH [1]Chander;LI [1]Jiansheng 机构地区：[1]National Maize Improvement Center of China, China Agricultural University, Beijing 100094, China;[2]National Key Lab of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China 出　　处：《Chinese Science Bulletin》索引2006年第51卷第12期,共10页 基　　金：The authors thank Dr.E.Coe for providing RFLP probes.This work was supported by the National Natural Science Foundation of China(Grant No.39893350);the State Key Basic Research and Development Plan of China(Grant No.2001CB 1088). 摘　　要：By adding thirty-one markers in the pre- vious linkage map, a new genetic linkage map con- taining 205 markers was constructed, spanning a total of 2305.4 cM with an average interval of 11.2 cM. The genotypic errors in the whole genome were de- tected by the statistical method and removed manu- ally. The precision of the linkage map was improved significantly. Main and epistatic QTL were detected by R/qtl, and main QTL were confirmed and refined by multiple interval mapping (MIM). Finally, MIM de- tected seven QTL for rows number, and five QTL for each grain yield, kernels per row and 100-kernel weight. The contribution to genetic variations of QTL varied from 35.3% for grain yield to 61.5% for rows number. Only kernels per row exhibited significant epistatic interactions between QTL. Twenty-four epistatic QTL were detected which distributed on almost all the ten chromosomes. About two-third epistatic QTL were observed between main QTL and another locus, which had no significant effects. These results indicate rather clearly that there are a number of QTL affecting trait expressions, not directly but indirectly through interactions with other loci. Thus, epistatic QTL effects may play a crucial role, if not more important than main QTL effects, in the genetic variation for the measured traits in present study. 关 键 词：基因扫描 分子标记 上位QTL 谷物 玉米