【作者】 刘亚娟；

【导师】 谭振波； 陈刚；

【作者基本信息】 首都师范大学 ， 植物学， 2006， 硕士

【摘要】 玉米是一种重要的禾谷类作物。由于干旱对玉米生产带来巨大损失，抗旱遗传育种已成为玉米遗传改良的一个重要方向。种子萌发、出苗是玉米生长的开始阶段，在土壤水分胁迫下保持较高的出苗率和壮苗率，直接关系到以后的生长发育和产量形成。出于玉米在生长期的许多抗旱相关性状是受多基因控制的，且受环境影响，使得抗旱性QTL的定位和遗传分析成为抗旱育种的理论指导。SSR标记技术的发展为研究抗旱遗传规律，定位重要抗旱性状提供了新的技术手段。本研究利用Mo17×黄早四的F₉重组自交系群体（共239系），构建分子图谱，并进行实验室模拟干旱胁迫环境下，芽苗期抗旱性状的QTL定位及遗传效应分析。主要结果如下： 1．从370对SSR引物中筛选出101对，应用mapmaker／EXP3.0b软件构建SSR分子标记连锁图谱。所构建的图谱覆盖玉米基因组1422.7cM，标记间平均图距为15.6cM，该连锁图谱与IBM群体所作图谱基本一致，能有效地进行QTL定位的研究。 2．运用复合区间作图法对玉米芽苗期抗旱QTL进行了定位和遗传效应分析。结果共检测到22个QTL分散在全部10条染色体。 3．在第1，5和10染色体上定位到种子萌发抗旱指数的三个主效QTL，与其连锁的SSR标记分别为umc1358，bnlg1006和phi050，相应的LOD值分别为3.76，4.79和2.17，加性效应分别为1.47％，-1.50％和-1.40％，其加性效应能解释表型方差分别为49.37％，50.53％和44.46％。 4．在正常供水条件下，在第4，8，9染色体上检测到3个苗期茎含水量QTL，与其连锁的SSR标记分别为phi021，dupssr14，bnlg1583，加性效应能解释表型方差为6.9％-14.40％，他们均来源于Mo17，其加性效应使含水量提高0.03％-0.04％。对于叶片含水量，检测到3个QTL，他们分别与邻近标记bnlg439，umc1867，nc134连锁，其加性效应能解释表型方差为7.03％-14.32％，来源于Mo17定位在第9染色体上QTL加性效应使含水量提高0.04％，另一个定位在第9染色体上的QTL和定位在第1染色体上的QTL增效基因均来源于黄早四。更多还原

【Abstract】 Maize is the third most improtant crop worldwide. In most maize-growing area, drought is by far the leading environmental stress causing yield reductions. Breeding for drought tolerance （DT） via gentic means is becoming a key aspect. Seed germination and early seedling growth is the beging stage for maize development. The ability of the seed to germination rapidly and uniformly under drought stress （DS） is a desirable trait for maize production. Maize response to DS is controlled by polygenes and is highly influenced by environmental variation. With SSR and many molecular marker mathods developed, it is possible to map DT related QTLs and make further analysis. In this study, a F₉RIL （recombinant inbred line） with 101 individuals, derived from a stress-tolerant Mo 17 and a stress-sensitive Huangzaosi, is used to construct a genetic map and located drought related QTLs. The results are as follows:1. A total of 370 microsatellite （SSR） markers cover 10 maize chromosomes were chosen to screen the parental lines Mol7 and Huangzaosi for polymorphism. 101 SSR markers were placed on a framework with program Mapmaker version 3.0b and spanned 1422.7 cM, the RIL map has an average SSR marker density 15.6 cM. The marker order was quite consistent and in agreement with published IBM map. So the map can be used to locate QTLs.2. Method of CIM （composite Interval Mapping） of program Windows QTL Cartographer version 2.0 was used to scan QTLs with intervals of 2 cM between markers and putative QTLs, and with a window size of 10 cM. Meanwhile the genetic effects of putative QTLswere analyzed.3. 3 quantitative trait loci （QTLs） for germination stress index （GSI） under DS were detected. Of these, one QTL located on chromosome 1, linked with marker umc1358, was contributed by Mo17 donor parent, the additive effect was 1.47%. which can explained 49.37% of the phenotypic variance, other two QTLs, located on chromosome 5 and 10, linked with marker bnlg1006 and phi050, were contributed by Huangzaosi donor parent, the additive effects were -1.50% and -1.40%. which can explained 50.53% and 44.46% of the phenotypic variance, respectively.更多还原