玉米穗长主效QTL q21EL-GZ的精细定位

Fine Mapping of the Ear Length Major QTL q21EL-GZ in Maize

穗长作为玉米产量的重要构成因子之一,具有较产量性状遗传力高的优势。研究穗长性状变异的遗传基础对于进一步解析玉米产量性状形成的遗传机制具有重要意义。本研究以课题组前期定位到的一个穗长主效QTL q21EL-GZ为研究对象,以黄早四作轮回亲本构建的携带目标区段的次级分离群体为材料,利用Sequenom SNP技术对含目标区段的BC_(1)F_(2)群体进行基因型鉴定,结合BC_(1)F_(2)和BC_(1)F_(2):3群体的穗长表型鉴定进一步缩小目标区段,将穗长主效QTL q21EL-GZ由1 Mb缩小到187.58 kb范围内。基于公共表达谱数据,利用生物信息学分析法筛选出q21EL-GZ的3个候选基因MTD1、RSH2和APK1B,为下一步的候选基因克隆和功能研究提供了基础靶标。

Ear length is one of yield components and shows higher heritability than that of yield trait in maize.Unlocking its genetic basis is important in order to understand the mechanism of maize yield formation.This study analyzed an ear length major QTL q21 EL-GZ that was identified in our research group.The secondary segregation population(BC_(1)F_(2))harboring the desirable target was used for the genotyping by taking use of the Sequenom SNP technology.The ear length was determined using BC_(1)F_(2)and derived BC1 F2:3 families.The target region containing q21 EL-GZ was further narrowed by using the group t test analysis method to a 187.58 kb interval.Based on the transcriptional profiles,three candidate genes MTD1,RSH2 and APK1 B of q21 EL-GZ were identified,which would be important targets in gene isolation and functional mechanism analysis.