Qtl analysis of flowering-related traits in maize (zea mays l.) using two connected populations | 基于两个相关群体的玉米花期相关性状QTL定位

Chinese. 【目的】利用具有共同亲本黄早四的2个F2s3群体,定位控制玉米的抽雄期（DTT）、散粉期（DTP）、吐丝期（DTS）以及散粉-吐丝间隔期（ASI）的QTL,为玉米分子育种与相关基础研究提供参考和依据。【方法】以自交系齐319和掖478分别与黄早四杂交构建的230个和235个F2s3家系为定位群体（分别写作Q/H和Y/H）,利用完备区间作图方法,对在不同生态环境下（2007-北京、2008-北京、2007-河南、2008-河南、2007-新疆以及2008-新疆）玉米花期相关性状进行QTL定位。同时利用基于混合线性模型的QTL Network-2.0软件进行基因×环境互作及上位性的分析。【结果】尽管4个花期相关性状的表现在2个群体中存在明显差异,但它们之间均呈现高度的相关性。在6个环境下对2个群体的4个性状进行了QTL检测,Q/H群体共定位到了85个QTLs,分布在玉米的10条连锁群上;Y/H群体共检测到了30个QTLs,呈现成簇分布。在Q/H群体中检测到2个重要的与多个性状相关且在不同环境条件下同时表达的QTL区域,分别位于第8染色体的umc1562―bnlg1651和第10染色体的phi062―umc1115区段;在Y/H群体中也检测到了1个与多性状相关且在多环境表达的QTL区域,位于第3染色体的nc030―umc2166区域。进一步分析发现,贡献率较大的QTL同时控制着多个性状。对比2个群体的定位结果,共检测到4个在不同遗传背景下的“一致性”QTLs。【结论】玉米花期相关性状的遗传机制较为复杂,而在不同环境及不同遗传背景下能够稳定存在的QTL可为这类性状的生产应用以及精细定位与图位克隆提供有价值的参考。

English. 【Objective】 Quantitative trait loci (QTL) for maize flower-related traits including days to tasseling (DTT), days to pollen-shedding (DTP), days to silking (DTS) and anthesis-silking interval (ASI) were mapped in two different F2:3 families with a shared male parent to provide reference for molecular breeding and related basic research in maize. 【Method】 230 and 235 F2:3 families derived from Qi 319×Huangzaosi population (Q/H) and Ye 478×Huangzaosi population (Y/H), respectively, under six different environments (2007-Beijing, 2008-Beijing, 2007-Henan, 2008-Henan, 2007-Xinjiang, and 2008-Xinjiang) were used to map QTL controlling four flower-related traits of maize by using the inclusive composite interval mapping method (ICIM). Meanwhile, QTL Network-2.0 was used to analyze epistasis among QTLs and QTL by environment interaction (QEI). 【Result】 Phenotypic analysis showed that DTT, DTP, DTS and ASI differed significantly in both Q/H and Y/H populations, while significant statistical correlations were observed between these flower-related traits in both populations. Under all of the six environments, 85 QTLs distributed on the 10 chromosomes were identified in Q/H, while 30 QTLs among which some were clustered were identified in Y/H for these four flower-related traits. Two and one important QTLs related to multiple traits were detected in each population, which were located on the interval of umc1562-bnlg1651 of Chrom. 8, phi062-umc1115 of Chrom. 10 and nc030-umc2166 of Chrom. 3, respectively. They could be expressed under different environments (may be called constitutive QTL). The results also indicated that those QTLs which could explain a relatively higher proportion of phenotypic variation seemed to control multiple target traits. Further, four QTLs were observed to be consistent between Q/H and Y/H. 【Conclusion】 Previous studies suggested that the genetic mechanisms of the flowering-related traits in maize are quite complicated. However, the results obtained here may give an important clue for precise mapping and positional cloning of QTL which could be stably expressed under different environments or genetic backgrounds.