【作者】 赵璞；

【导师】 张祖新； 陶勇生；

【作者基本信息】 河北农业大学 ， 作物育种学， 2011， 硕士

【摘要】 导入系（Introgression Lines,ILs）是利用多代回交和分子标记辅助选择构建的永久定位群体,是进行QTL遗传分析的理想材料。与传统的定位群体相比,单片段导入系具有遗传背景清楚、群体遗传稳定、QTL定位和鉴定的精确度和灵敏度高、QTL遗传效应分析准确等优点。鉴定玉米产量相关性状基因位点及包含有利等位基因的导入系,可为了解产量性状形成的遗传基础及针对玉米自交系产量性状的分子设计提供参考和依据。本研究以QB80和Qi319为供体亲本,掖478为轮回亲本,从BC1开始,每个回交世代取不少于50个单株的混合花粉与掖478连续4代回交,得BC4F1,BC4F1自交形成240-300个单株BC₄F₂。根据产量性状与掖478存在的差异实施定向选择BC₄F₂单株连续自交2代形成61个和72个家系的基础导入系群体。通过2年4点田间试验,利用完备复合区间作图进行产量及其相关性状的QTL（Quantitative Trait Locus, QTL）分析。主要研究结果包括:1.四个环境下,在QB80为供体的导入系群体中,共检测到10个性状的55个QTLs;在Qi319为供体的导入系群体中,检测到10个性状的49个QTLs。在2个及以上环境中均检测到的QTLs有18个。QB80与掖478间的遗传差异较Qi319更大,QB80为供体的导入系群体中能检测更多的产量性状QTL。2.同一性状在不同环境下所检测的QTL定位在相同的染色体区域,不同性状的QTL也定位于在相同或临近的染色体区域,形成多个QTL富集区。QTL富集区是为产量性状基因的克隆提供可供参考的重要染色体区域。两个群体所检测的QTL位点具有较少的一致性,说明2个供体材料中含有不同的有利基因位点。3.导入片段中含有利基因的导入系,其相关性状明显得以改良,这些导入系可用于QTL聚合以改良掖478的产量相关性状。更多还原

【Abstract】 Introgression Lines(ILs)was a permanent mapping population, which was developed using advance-backcross and marker-assisted selection, which is a novel materials for quantitative trait locus (QTL) genetic analysis. Comparing with the traditional population, there were more advantages in SSILs, such as knowable genetic background and steady genetic base; the accuracy and sensitivity of QTL mapped and identified were improved; genetic effects of QTL can be exactly analyzed. The purpose of this investigation was to identify QTL (Quantitative Trait Locusi) for maize yield related traits and those introgression lines containing favorable alleles.The two maize inbred lines, QB80 and Qi319 were used as the donor parents, respectively, and the Ye478 as the recurrent parent, two introgression line populations consisting of 61 and 72 family lines were constructed by backcrossing combined with directional selection, respectively. The two introgression line populations were evaluated across 4 environments in 2 years. The QTLs for yield and related traits were detected by stepwise regression (RSTEP-LRT) using Windows QTL ICI Mapping software. The results were as follows:1. Total of 55 QTLs for 10 traits were identified in the population with QB80 as the donor, and 49 QTLs for 10 traits were identified in the population with Qi319 as the donor under four environments. Of which 18 QTLs were detected across not less than two environments. The genetic difference between QB80 and Ye478 are more than that of Qi319 and Ye478, therefore, more yield trait QTL can be detected in the population with QB80 as the donor.2. In addition, some QTL for same trait detected in different environments were located in the same chromosome regions, and those QTL for diverse traits were also located in the same or adjacent chromosome region, forming several multiple QTL-rich regions. The detected QTL-rich regions have given a subset of important chromosome regions for fine mapping and cloning of genes for yield associated traits.The less consistent QTL was detected in two populations, indicating that the two donors contain different set of favorable alleles.3. The yield associated traits of those lines containing favorable introgression segments or alleles were significantly improved, implicating those lines are available for improving of Ye478 by QTL pyramiding.更多还原