基于SNP遗传图谱定位玉米雄穗分枝数和主轴长QTLs

QTLs mapping of tassel branch number and tassel total length in maize based on SNP genetic map

以玉米雄穗分枝数差异显著的自交系豫086(分枝数多)和豫M 1-7(分枝数少)杂交获得F1,通过单粒传法获得含177个株系的F7 RIL群体。以玉米10 kb SNP芯片进行RIL群体基因分型,构建高密度遗传图谱,并利用QTL Cartographer 2.5对郑州和海南2个环境下玉米雄穗分支数(Tassel branch number,TBN)和玉米雄穗主轴长(Total tassel length,TTL)进行QTL分析。结果表明,构建的高密度遗传图谱覆盖玉米10条染色体,包含1 792个簇,覆盖基因组长度为2 109.45 cM,相邻簇之间平均距离为1.18 cM。在此图谱基础上采用复合区间作图法,在2个环境下共检测到了24个雄穗相关性状QTLs。其中7个与TBN相关QTL分布于第3, 8和10条染色体上,单个QTL的表型变异范围是6.74%~13.88%;其余17个为与TTL相关QTL,位于第1,3,5,6,8和9染色体上,单个QTL位点可解释5.59%~18.66%的表型变异。在2个环境下检测到了一个相同的TTL相关QTL位点(qTTL1-2)和2个既控制TBN又控制TTL的QTL位点(qTBN8郑州,qTTL8郑州;qTBN8-3海南,qTTL8海南)。

We derived F1 through the maize tassel branch number significant difference from self-crossing Yu 086(multi-branch type) and crossbreeding Yu M 1-7(less-branch type), and obtained F7 RIL population with 177 strains by single-seed descent method. The genetic types of this RIL population were identified by using Maize 10 kb SNP array to construct the high-density genetic linkage map.QTL analyses were conducted on maize tassel branch number(TBN) and maize total tassel length(TTL) of maize grown in two regions of Zhengzhou and Hainan by using QTL Cartographer 2.5. The results showed that the constructed high-density genetic linkage map contained 1 792 bins and 10 linkage groups with a total length of 2 109.45 cM and an average distance between adjacent bin-markers of 1.18 cM. On this basis using the composite interval plotting method, a total of 24 tassel-related QTLs were identified for maize grown in the two enviroments..Of these QTLs, 7 were related to TBN, which were located on chromosomes 3, 8 and 10 in maize genome and accounted for 6.74%~13.88% of the phenotypic variation for a single locus. The other 17 QTLs were related to TTL, which were distributed in chromosomes 1, 3, 5,6,8 and 9, and the phenotypic variation of a single locus was 5.59%~18.66%. Furthermore, we found one common QTL(qTTL1-2) of TTL in maize grown in the two regions, and two QTLs in each region(qTBN8 Zhengzhou,qTTL8 Zhengzhou;qTBN8-3 Hainan,qTTL8 Hainan)were observed to control both TBN and TTL, respectively.