【作者】 邵元健；

【导师】 潘学彪；

【作者基本信息】 扬州大学 ， 作物遗传育种， 2005， 博士

【摘要】 水稻卷叶性状是超高产株型育种的重要形态指标之一,并在高产或超高产品种中得到充分的体现。卷叶性状对叶片光合生理、群体生态效应及经济性状的影响的研究表明,适度卷叶对塑造个体良好的株型、改善生育后期群体质量、提高产量具有良好的效应。 目前发现的卷叶材料比较多,但叶片卷曲程度差异较大,也还没有关于卷叶基因精细定位和克隆的报道。因此,本研究选择了两种代表性的卷叶材料,剑叶分别表现为中度卷曲（91SP068）和高度卷曲（卷叶珍汕97B,JZB）,并分别与平展叶品种奇妙香（QMX）配制杂交和回交组合,对F₂代和/或回交后代卷叶性状进行了遗传分析,同时对卷叶基因进行了精细定位。主要研究结果如下: 1.卷叶基因rl_t的遗传分析及其精细定位 为定位来自JZB的卷叶基因,利用其作为卷叶基因供体亲本,构建了QMX为背景的卷叶基因近等基因系,并以回交后代为材料开展研究: BC₄F₂和BC₄F₃代分离出3种剑叶卷曲类型,即卷叶、中度卷叶和平展叶,3种表型的植株个数分离比测验表明,符合1对主基因1:2:1的理论分离比例;而BC₅F₁群体中则分离出两种剑叶类型（中度卷叶和平展叶）,分离比测验符合1:1的理论比例。两群体卷叶性状遗传分析说明JZB的卷叶性状受1对主基因的控制。而且,中度卷叶个体的剑叶卷曲形态和卷曲度（LRI）平均值均与平展叶接近,与卷叶相差较大,表明卷叶基因是隐性基因,命名为rl_t。 基因定位基本路径为:首先,采用SSR标记和新开发的INDEL标记,通过BSA法在卷叶DNA池和平展叶DNA池间筛选多态性标记,并用MAPMAKER/EXP3.0构建遗传连锁图,然后,采用复合区间作图法（CIM）进行基因定位。其中,INDEL标记的开发,是以水稻粳稻品种日本晴克隆序列为基础,利用NCBI在线核酸比对工具,与籼稻品种9311基因组比对,发现核酸更多还原

【Abstract】 Semi-rolled leaf is one of the most important morphological characters in plant breeding. Many high yield varieties or their hybrids were semi-rolled leaf cultivars, such as Peiai64s, E32, Lunhui422. A series of studies on effects of leaf rolling on photosynthetic physiology and yield trait all showed that semi-rolled leaf had some upstanding effects, for instance making leaf erect, optimizing canopy light transmission, increasing effective leaf area per unit land, improving the quality of population in late growth stage.However, leaf rolling in rice appeared to be a complex trait since different cultivars had different leaf rolling degrees. Some of them rolled slightly, some rolled moderate, and others rolled cylindrically. Furthermore, there were no reports about fine mapping or cloning of genes for leaf rolling until now.Therefore, two representative varieties were selected to study, one of which was 91SP068, a semi-rolled mutant from progenies of protoplasm culture of Mabelle, and the other was JZB, a NIL of Zhenshan97 carried a major gene for leaf rolling from Liugangjuanyej. The results of genetic analysis and fine mapping of genes controlling leaf rolling related to these two varieties were reported as following: 1. Fine mapping of a major gene rl(t) for leaf rollingFor genetic analysis of leaf rolling, three populations (BC4F2, BC5F1, BC4F3) were derived from a cross between QMX a non-rolled leaf variety as a recurrent parent, and JZB, as a donor parent carried genes for leaf rolling.In BC4F2 and BC4F3 populations, three apparent phenotypes of flag leaf were non-rolled, semi-rolled and rolled, which of them rolled leaf plants could be easily identified from the others. While in BC5F1 population, there were two phenotypes of flag leaf, semi-rolled leaf and non-rolled leaf. The segregation ratio of different phenotypes showedgoodness of fit for the ratio of single Mendelian segregation (non-rolled leaf: semi-rolled leaf: rolled leaf ≈ 1:2:1 in BC4F2 and BC4F3; semi-rolled leaf: non-rolled leaf ≈1:1 in BC5F1). Genetic analysis indicated that rolled leaf of JZB was controlled by one major gene. In addition, the morphology and the leaf rolling index (LRI) of semi-rolled leaf plants were close to that of non-rolled leaf plants. Therefore, the gene from JZB was a recessive gene, termed rl(t)BC4F2 population with 241 plants was constructed to map gene for leaf rolling. First, twenty typical rolled leaf plants and twenty non-rolled leaf plants from BC4F2 were selected to build rolled leaf and non-rolled leaf DNA bulk, respectively. Then, eight polymorphic markers located on chromosome 2 were screened from 500 SSR markers and 15 developed insert/delete (INDEL) markers by bulked segregation analysis (BSA), and a genetic linkage map was constructed by MAPMAKER/EXP3.0. QTL analysis was achieved by composite interval mapping conducted with WinQTLcart2.5. Based on the segregation data of BC4F2 population, rl(t) was primarily mapped between two markers INDEL112 and RM3763, away 1.0 cM from INDEL112 . Furthermore, the result of progeny test of some BC4F2 plants was consistent with the mapping result.To fine map rl(t), one BC4F3 population with 855 plants was generated from a semi-rolled leaf plant in BC4F2, which genotypes of marker flanking rl(t) were heterozygote. In addition, new INDEL markers were developed by blasting the sequence of PAC covering rl(t) of the japonica variety Nipponbare (http://rgp.dna.affrc.go.jp/) to that of the indica variety 93-11 online, and four of them showed polymorphism between two bulks. These four markers with other four markers screened in preliminary mapping were then used to survey the total of 191 rolled leaf plants in BC4F3. Their linkage relationship showed that two markers of them, INDEL112.6 and INDEL113, were inserted into the region between markers INDEL112 and RM3763. Of 191 rolled leaf plants, there was only 1 recombinant between INDEL113 and rl(t) , 5 recombinants between INDEL112.6 and rl(t), and far away from INDEL112.6 and ENDEL113, more recombinants occurred, indicating that更多还原