【作者】 罗继景；

【导师】 朱瑞良； 林鸿宣；

【作者基本信息】 华东师范大学 ， 植物学， 2005， 硕士

【摘要】 水稻(Oryza sativa L.)是一种重要的粮食作物,水稻的大多数性状为多基因控制的数量性状,将数量性状基因座(quantitative trait loci,QTL)剖分为单个孟德尔因子进行研究,对了解水稻的生长发育机制及改良水稻品质、增强水稻的抗逆性等方面具有重要的意义。如何将数量性状基因座(quantitative trait loci,QTL)剖分为单个孟德尔因子,一个重要的策略就是构建染色体片段替换系(chromosome segment substitution lines,CSSL),CSSL消除了遗传背景的干扰,是用于QTL分析的一种重要实验材料。本实验以非洲稻(Oryza glaberrima Steud)为供体亲本,以95-22(Oryza sativa L.)为轮回亲本,通过回交及分子标记辅助选择(maker assisted selection,MAS)构建染色体片段替换系,并选用其中的88个染色体片段替换系对水稻最长根长(maximum root length,Mrl)QTL及轮生枝梗(whorled primary branch,Wpb)基因进行初步定位和精细定位。主要获得以下实验结果:1. 用DNA分子标记对两亲本之间的多态性进行检测,经过检测,其中有118个标记具有明显多态性,这118个标记覆盖了水稻的整个基因组,整个图谱总长度为1531. 1 cM,标记平均间距为14. 44 cM。2. 构建了187个以95-22为遗传背景的替换系群体,由于还有些区段缺失供体亲本的染色体片段,所以这个替换系群体的导入片段没有完全覆盖水稻整个基因组,还有158. 81 cM区段未覆盖,覆盖率为89. 62%。3. 利用88个染色体片段替换系对水稻的最长根长QTL及轮生枝梗基因进行了定位,在2,4,9,10号染色体各定位到了1个最长根长QTL,在7号染色体上定位到2个QTL。另外在4号染色体上定位到了一个控制轮生枝梗的基因。4. 在精细定位过程中,在2号和10号染色体上各发现了1个新的最长根长QTL,对位于2号染色体最长根长QTL Mr12和位于4号染色体轮生枝梗基因Wpb4进行精细定位,在存在QTL或基因的2个标记间寻找更多的具有多态性的标记建立饱和连锁图谱,继续进行下一步的精细定位。更多还原

【Abstract】 Rice (Oryza sativa L.) is the world’ s most important food crop, and its most traits are quantitative traits, which are controlled by polygenes. To study quantitative trait loci (QTL) by dissecting a QTL into single Mendelian factors is significant in understanding the growth and development of rice, and improving the yield and stress resistance of rice. An important strategy for dissecting a QTL is by constructing chromosome segment substitution lines (CSSL). The advantage of a CSSL in mapping QTLs is that, CSSL eliminate the "noise" of the genetic background. The present research has developed a CSSL population which choromosome segments from Africa Rice {Oryza glaberrima Steud) (donor parent) were introgressed into an elite genetic background of 95-22(recurrent parent), using backcross and marker-assisted selection(MAS). We mapped and analyzed the QTL for maximum root length (Mrl) and the gene for whorled primary branch (Wpb) using 88 chromosome segment substitution lines selected from CSSL population. The main results are as follows:1. The polymorphism between 95-22 and Africa Rice was detected by using DNA markers, including SSR markers, STS markers, and CAPS markers. 118 markers showed definite polymorphism, which covered the whole genome of rice. All these markers covered 1531.1 cM in length with average distance of 14.44 cM between adjacent markers.2. 187 overlapping chromosome segment substitution lines with the 95-22 genetic background have been developed. This CSSL population did not cover the whole genome of rice because 158. 81 cM chromosome regions uncovered by donor parent chromosome segments. The covered percentage is 89.62%.3. We identified 2 QTLs for Mrl on chromosome 7 and 4 QTLs for Mrl on chromosome 2,4,9,10, respectively. And identified a gene for Wpbon chromosome 4.4. We identified 2 new QTLs for Mrl on chromosome 2 and 10 in fine mapping, respectively. To fine map QTL for Mrl on chromosome 2 and Gene for Wpb on chromosome 4. we detected and will detect more polymorphism markers among target regions with putative QTL/Gene and construct saturated linkage map for further fine mapping.更多还原