【作者】 陈代波；

【导师】 曹立勇；

【作者基本信息】 中国农业科学院 ， 作物遗传育种， 2010， 硕士

【摘要】 花器官的研究一直是植物分子生物学研究的热点,长护颖突变体的鉴定和研究有利于进一步地补充和阐明水稻花器官发育的分子机理;理想株型是保证杂交水稻高产的基础,窄叶作为水稻叶形的一种,对理想株型的塑造起了重要的作用。本研究在地方栽培稻品种“鸭血糯”中发现了一个水稻长护颖自然突变体,暂时命名为Osleg。该突变体表现为护颖发育异常且长于整个果实,种子萌发缓慢,发芽率低,生育期延迟等性状,组织细胞学观察发现,长护颖突变体护颖的远轴表皮细胞凸凹不平,毛状体较多,许多瘤状体轴向平行排列,与外稃表皮细胞结构相似。同时,从特青的EMS突变体库中,发现了一个水稻窄叶突变体,暂时命名为nal。经初步观察发现,窄叶突变体表现出叶片高度内卷,叶绿素检测结果显示,窄叶突变体的剑叶叶绿素含量显著低于野生型,其它表型差异不显著。为了定位这两个突变性状,分别将Osleg和nal纯合体与籼稻品种9311杂交构建F2和F3群体用于表型鉴定、遗传分析和基因定位。结果如下:1.遗传分析表明,在Osleg∕9311的F2代群体中,控制水稻的长护颖突变性状是受一对隐性核基因控制的。利用已公布的水稻SSR标记将Osleg位点初步定位在水稻第7染色体短臂上RM3222和RM3325两个标记之间。然后,利用自行设计的STS标记对Osleg位点进一步精细定位,最终将OsLEG基因定位在水稻7号染色体短臂上的LC15和LC25标记之间,物理距离约207kb,为进一步克隆OsLEG基因和研究禾本科植物花器官的分子调控机理奠定了基础。2.遗传分析表明,在nal∕9311的F2代群体中,控制水稻的窄叶突变性状是受一对隐性核基因控制的。为了定位该基因,选取了500株窄叶突变株作为窄叶性状的基因定位群体,运用本实验室均匀分布在水稻12条染色体上的533对SSR标记对两亲本进行多态性筛选,其中233对在亲本间呈现出多态性,多态性频率为41.8%。更多还原

【Abstract】 The research on floral organ is always hot to plant molecular biologists. The studies on long empty glumes mutant may further elucidate additionally that the molecular mechanism of rice floral development. Ideal plant type is the base of hybrid rice with high yield. As one kind of leaf shape, narrow leaf plays an important role in building the ideal plant type of rice.In this study, we obtained a long empty glumes mutant, provisionally named Osleg, from the cultivar called‘Yaxuenuo’. Several abnormal morphological characteristics, including two long empty glumes longer than the fruit, slower seed-germinating, later growth period were observed. Using scanning electron micrograph, we observed that the abaxial surface of the mutant Osleg is rough, formed some trichomes, arranged in some tubercles in parallel, which is very similar to the lemma of the mutant and contrast. We also discovered narrow leaf mutant, provisionally named nal, from the EMS mutant library in rice. Through the observation, the mutant was very dwarf with highly inward rolling leaves. At the heading stage, the chlorophyll content detected by the portable chlorophyll testing system showed that the content of chlorophyll in the flag leaf of mutant reduced compared with the contrast.To mapping the two mutant traits, we constructed F2 and F3 populations by crossing between the two mutants and 9311 respectively for phenotype analysis, genetic analysis and gene location. The results listed as follows:1. To map the OsLEG gene, F2 population was constructed by a cross between Osleg and 9311. A total of 1485 long empty glumes plants and 4302 normal plants were observed in F2 population fitting for the 3:1 segregation ratio through the chi-square test. The result of genetic analysis indicated that the mutation was controlled by a single recessive gene. Some published SSR markers were used to map the OsLEG gene on the on the short arm of chromosome7 between RM3222 and RM3225. To fine-map the OsLEG gene, we designed some STS markers. Ultimately, the OsLEG gene was located on the short arm of chromosome7 between LC15 and LC25 in a 207kb region. These results provided the foundation for the further cloning the OsLEG gene and study on the molecular mechanism of floral development in monocot.2. Genetic analysis showed that the mutant character was controlled by a single ressesive gene based on the field observations on a F2 population crossed between nal and 9311. A total of 500 narrow leaf mutants from the F2 population were selected to map the mutable gene. 533 pairs SSR markers, which distributed on 12 chromosomes equably, were used to screen the polymorphism between the two parents. 233 pairs of them were polymorphic markers with the polymorphism rate of 41.8%.更多还原