控制玉米雄穗分枝数目和雄穗重的主效QTL的定位

利用2套具有共同亲本黄早四且分别含有230个及235个家系的F_2:3群体, 结合2年多点的表型鉴定, 运用完备复合区间作图方法对不同生态环境下(2007-北京、2008-北京、2007-河南、2008-河南、2007-新疆以及2008-新疆)的玉米雄穗分枝数和雄穗重进行QTL定位。同时, 利用基于混合线性模型的QTLNetwork-2.0软件进行基因×环境互作及上位性分析。6个环境下2个群体共检测到51个与雄穗分枝数和雄穗重相关的QTL(Q/H群体32个, Y/H群体19个), 其中包括7个主效QTL, 并在Q/H群体中确定了2个重要的QTL, 即位于7.01bin的Qqtpbn7-1和位于7.02bin的Qqtw7-2。对比2个群体的定位结果, 共挖掘到3个在不同遗传背景下的“一致性”QTL, 这些在不同环境及不同遗传背景下能够稳定存在的QTL可为玉米雄穗相关性状的生产应用以及精细定位提供有价值的参考。

Major Quantitative Trait Loci Analysis of Tassel Primary Branch Number and Tassel Weight in Maize (Zea mays)

Tassel-related traits of maize are important for modern maize breeding and production. To understand the genetic basis of tassel traits, we evaluated 230 and 235 F_2:3 families derived from the Qi319×Huangzaosi population (Q/H) and the Ye478×Huangzaosi population (Y/H), under 6 different environments (2007-Beijing, 2008-Beijing, 2007-Henan, 2008-Henan, 2007-Xinjiang, and 2008-Xinjiang). We aimed to map quantitative trait loci (QTL) controlling tassel primary branch number and tassel weight by using the inclusive composite interval mapping method (ICIM). QTLNetwork v2.0 was used to analyze epistasis among QTL and QTL-by-environment interaction. We identified 51 QTL controlling tassel-related traits in the 2 populations (32 QTL in Q/H and 19 in Y/H), with 7 major QTL detected. The umc2160–umc1016 interval on chromosome bin 7.01 (Qqtpbn7-1) and bnlg1094–bnlg1579 on bin 7.02 (Qqtw7-2) were found to be important QTL regions for the Q/H population. Furthermore, 3 QTL were consistent between Q/H and Y/H. The QTL that were consistent in different environments or genetic backgrounds could be useful for precision mapping and positional cloning.