水稻窄叶突变体nal12的鉴定与基因精细定位

【目的】水稻叶片是理想株型的主要组成部分。筛选和鉴定新的叶形突变材料,可为研究叶发育调控机制和塑造叶片理想形态打下基础。【方法】由粳稻品种武运粳31经EMS(ethyl methane sulphonate)诱变获得窄叶突变体nal12(narrow leaf 12);通过表型测量分析剑叶至倒4叶的叶片长度、宽度、大脉数和小脉数,并进行组织切片和显微观察;将突变体nal12与籼稻品种台中本地1号(TN1)杂交,在F₂分离群体中选取了1709个具窄叶突变表型的单株,通过已有的SSR、STS和新开发的分子标记进行精细定位。【结果】nal12在幼苗期就表现出了窄叶性状,在成熟期植株较野生型矮小,分蘖增多,茎秆变细。经组织切片观察分析,nal12叶片变窄是由于大脉和小脉数量减少造成。遗传分析表明该窄叶表型受单一隐性核基因调控;最终将该基因定位在第10染色体上LC2-RF37与LC4R-RF39标记之间约64.7 kb的范围内。该区间内共有10个开放阅读框,其中并无已报道的窄叶相关基因。qRT-PCR结果表明,NAL12基因的突变会影响生长素合成与运输相关基因的表达。【结论】NAL12为一个新的叶形调控基因。这为进一步研究水稻叶片发育,丰富其分子调控网络打下了基础。     

水稻窄叶突变体nal10的鉴定与基因精细定位

利用EMS诱变粳稻品种武运粳7号获得一个新窄叶突变体nal10,该突变体在苗期表现出极窄叶和弱小的特征,在生殖期表现出矮化、窄叶、畸颖和不育的表型。组织解剖学分析表明,nal10的叶片窄化可能是由于叶片大脉和小脉数量减少造成的。遗传分析表明,该窄叶表型受一对隐性核基因控制。利用nal10与台中本地一号(TN1)构建的F₂群体,通过混合分离法,在第1染色体上找到3个紧密连锁的SSR标记(RM1287、RM562和RM5638)。进一步利用新发展的分子标记,最终将该基因定位在STS标记PK83和PK78之间的55.2 kb范围内,该区间共有8个开放阅读框。RT-PCR分析表明,NAL10的突变能够造成生长素生物合成、信号转导和运输基因转录水平的下降,因此NAL10是一个与生长素相关的窄叶新基因。这些结果为进一步克隆该基因、丰富水稻叶发育的遗传调控网络打下了基础。     

水稻窄卷叶突变体Nrl3(t)的基因定位

利用⁶⁰Co-γ射线辐射诱变籼稻恢复系中恢8015,获得了一份窄卷叶突变体Nrl3(t)。与野生型中恢8015相比,突变体叶片显著变窄内卷、株高降低、穗长变短、结实率降低、千粒重降低、粒长粒宽减小。细胞学分析表明,突变体维管束减少和泡状细胞不够饱满是导致叶片变窄卷曲的原因。遗传分析表明该突变体受一对隐性核基因控制,以窄卷叶突变体Nrl3(t)与粳稻品种02428杂交获得的F₂分离群体作为定位群体,利用SSR标记和新开发的InDel标记,将窄卷叶基因Nrl3(t)定位于第2染色体长臂标记C9和C10E之间约70.3 kb区间内。研究结果为该基因的克隆及进一步揭示水稻窄卷叶形成的分子机理奠定了基础。     

抑制OsAGO1a基因的表达导致水稻叶片近轴面卷曲

 AGO蛋白是RNA诱导沉默复合体的核心元件,在植物生长发育过程中发挥着重要作用。通过分别特异性地扩增OsAGO1a基因中第2外显子和第11~12外显子的片段,构建了两个干涉载体OsAGO1aI 1E和OsAGO1aI 2E。利用农杆菌介导法转化水稻品种日本晴,抑制OsAGO1a基因的表达,借此研究OsAGO1a的功能及其对水稻生长发育的影响。结果表明, 抑制OsAGO1a的表达导致叶片的近轴面卷曲而对其他主要农艺性状的影响不大。     

水稻小粒矮突变性状与T-DNA插入标签的共分离检测

 从T-DNA水稻标签系中发现1个标签系中出现了小粒矮(sgd)突变性状的分离。为克隆该突变基因和进行基因功能研究,对该突变体进行了遗传分析。该标签系存在多个插入事件,且T3代发现目标突变性状分离系中,另一个非目标插入事件已经纯合,故特异PCR检测不能确认小粒矮突变性状与T-NA插入共分离。但通过TAIL-CR方法,获得了插入点侧翼的水稻基因组序列,并证实该侧翼序列与小粒矮突变性状共分离。     

水稻粒宽突变体gw4的鉴定与基因定位

[目的]水稻粒形是影响水稻产量和决定稻米外观品质的主要性状之一.筛选和鉴定新的粒形突变材料,可为研究水稻籽粒发育的调控机制奠定基础.[方法]粳稻品种中花11经1％的EMS处理,在诱变群体中获得一份窄粒突变体gw4(grain width on chromosome 4);分析粒形和其他主要农艺性状,在扫描电镜下观察颖壳...     

MULTI-FLORET SPIKELET 4(MFS4) Regulates Spikelet Development and Grain Size in Rice

In rice, the spikelet is the basic unit of inflorescence, and its development is important for determining the grain yield and quality. We reported a rice spikelet mutant multi-floret spikelet 4(mfs4) which resulted in the production of extra floral organs or a whole extra floret, and elongated sterile lemmas. The results suggested that the mutation of the MFS4 gene interfered with spikelet meristem determinacy and floral organ identity. In addition, the plant height and the grain length and width in the mfs4 mutant were all less than those in the wild type. Using the bulked segregant analysis method, the MFS4 gene was localized in a 557-kb region on the long arm of chromosome 1. Sequence analysis showed that there was a C-base deletion at the open reading frame of LOC_Os01 g67430. Further tests indicated that a wild type copy of LOC_Os01 g67430 was able to reverse the mfs4 defects, which indicated that LOC_Os01 g67430 was the MFS4 gene. The MFS4 gene encodes a lipase located in the mitochondria and is expressed strongly in the young inflorescence. qRT-PCR results showed that the expression of some genes that were known to regulate spikelet meristem determinacy and grain size were decreased in the mfs4 mutant, which indicated that the MFS4 gene regulates spikelet meristem determinacy and grain size by modulating the expression of these genes.     

Physiological Characters and Gene Mapping of a Yellow Leaf and Early-senescence Mutant osyes1 in Rice

【Objective】Leaf is a main photosynthetic organ and its color mutants of rice are ideal materials for the study of photosynthesis, chlorophyll biosynthesis and metabolism, and chloroplast development in plants. 【Method】The mutant osyes1 (Oryza sativa yellow-leaf and early senescence 1) was obtained through 60Co γ-radiation treatment of indica cultivar Zixuan 1. The seedlings of osyes1 and its wild type were treated with exogenous H2O2. The SOD and CAT activities, ROS level, MDA content, soluble protein contents, chlorophyll contents, the net photosynthetic rate and chloroplast ultrastructure were analyzed for osyes1 and its wild type leaves at heading stage. The main agronomic traits of osyes1 and its wild type plants were analyzed under field conditions at maturation stage in Hangzhou. The recessive individuals in F2 population derived from osyes1/02428 were used to locate the gene by the map cloning method.【Results】The yellow-leaf and early-senescence symptoms started at 3- or 4-leaf stage, and gradually spread to all of the leaves after heading. Due to the early-senescence of the leaves of the mutant osyes1, its major agronomic traits including plant height, panicle length, grain number per panicle and the seed setting rate were markedly reduced. Moreover, the mutant osyes1 exhibited hyper-sensitivity to exogenous H2O2. The physiological analysis indicated that the contents of chlorophyll and the activities POD and CAT in the third-top leaf was significantly lower than those in the flag leaf and the second-top leaf in wild-type (WT) plants, but all of them in the mutant plants were significantly lower than those in its WT. Compared with the WT plants, the contents of MDA, H2O2 and O2− followed a steady increasing trend in the flag, second-top and third-top leaves of the mutant, while their soluble protein levels were progressively dropping. Genetic analysis confirmed that osyes1 was controlled by a single recessive nuclear gene, which was mapped to a region of 708 kb flanked by two SSR markers (RM21353 and RM21384) on the short arm of chromosome 7. 【Conclusion】In this work, the main agricultural traits were significantly reduced in osyes1 for the yellow leaf and early senescence. OsYES1 was located in a 708 kb range between RM21353 and RM21384 by map-based cloning strategy.     

水稻黄叶早衰突变体osyes1的生理特性和基因定位

【目的】叶片是水稻进行光合作用最重要的器官。叶色突变体是研究光合作用、叶绿素合成代谢和叶绿体发育的重要材料。【方法】利用⁶⁰Co辐射诱变中籼恢复系自选1号,获得黄叶早衰突变体osyes1。幼苗期对突变体和野生型进行外源H₂O₂处理。抽穗期对突变体和野生型叶片进行超氧化物歧化酶活性、过氧化氢酶活性、活性氧含量、丙二醛含量、可溶性蛋白含量、叶绿素含量、净光合速率测定以及透射电镜观察。成熟期考查突变体和野生型的主要农艺性状。以osyes1/02428的F₂群体中的隐性单株为作图群体,利用图位克隆方法定位OsYES1基因。【结果】osyes1的突变性状始于3~4叶期,水稻抽穗后,所有叶片均表现为黄叶衰老症状,致使突变体株高、穗长、每穗粒数及结实率极显著低于野生型对照。与野生型对照相比,突变体幼苗对外源H₂O₂更敏感。生理分析表明,孕穗期野生型倒3叶的叶绿素含量、过氧化物酶和过氧化氢酶活性极显著低于倒2叶和剑叶,而突变体的含量则极显著低于野生型且依次极显著降低;与野生型相比,突变体剑叶、倒2叶和倒3叶的丙二醛、H₂O₂和O₂^-含量极显著增加,而可溶性蛋白含量则相反。遗传分析表明,osyes1受一对隐性核基因控制,利用图位克隆技术将OsYES1基因定位于第7染色体短臂的RM21353与RM21384之间,物理距离为708 kb。【结论】由于osyes1叶片过早黄化衰老导致与产量相关的重要农艺性状显著下降。OsYES1基因定位在第7染色体两个SSR标记(RM21353和RM21384)之间的708 kb的物理区间内。     

Characterization and Genetic Analysis of Rumpled and Twisted Leaf Mutant(rtl1) in Rice

A rumpled and twisted leaf 1(rtl1) mutant was generated from a japonica cultivar Nipponbare by ethyl methanesulfonate treatment,which was characterized as rumpled and twisted leaf at the seedling stage.The F2 populations were constructed by crossing with indica cultivars TN1 and Zhefu 802,respectively.Genetic analysis demonstrated that the phenotype was controlled by a single recessive nuclear gene.The closely linked simple sequence repeat(SSR) marker RM1155 was obtained from bulked segregant analysis.Subse...     

灌浆结实期弱光对水稻产量、生理及品质的影响

试验研究了灌浆结实期水稻群体光照强度的变化规律以及弱光对生物产量与物质分配和群体光合速率及生理变化的影响。结果表明,群体内的相对光照变化相对环境光照出现滞后性。在抽穗后水稻群体光照的垂直分布中群体中上部差异较大,群体下部差异较小。水稻在抽穗后光照强度降至对照的80％时,单株产量、生物产量、粒重、结实率和成熟后的谷草比都没有显著的变化;但当光照强度降至对照崎的60％时,则上述指标显著降低;当光照强度降至对照的20％时,植株几乎停止了生长。随着光照的减少,干物质在茎叶和穗中的积累量都有所下降,会出现负积累量,而干物质在叶和茎鞘中的分配比率增加,在穗中的比率减少：除对粒型外,弱光照对其他品质指标造成显著影响,其中垩白指标受影响最为显著：气孔导度和蒸腾速率也随着光照的减弱而减小。     

小粒型优质野败不育系绮A的选育与应用

绮A是广西农科院水稻所育成的极小粒型野败不育系，千粒重仅14g，具有败育彻底，异交习性良好，可恢性，配合力高，外观品质好等特点。2001年10月通过广西区科技厅成果鉴定。所配组合表现米质优、优势强、产量高、熟期偏中迟。绮优1025、绮优99和绮优293等优质早灿组合的配组成功，有望解决华南杂交早灿稻米质差的问题。     

一个水稻类病变黄叶突变体的鉴定和精细定位

从15000多个水稻转基因株系中发现了一个类病变黄叶突变体.该突变体最显著的特征为叶片由下而上依次黄化,同时出现类似病原体感染的病斑.根据突变体表型,将该突变体命名为syll(spotted and yellow leayes 1).遗传学分析表明,该突变性状受1对隐性核基因控制.PCR检测和潮霉索抗性分析显示.该突变...     

水稻旱育秧抗性生理与结实性状的研究

水稻旱育秧苗电解质与可溶泄糖泄漏低于水育秧苗，束缚水、ｐｒｏ含量高于水育秧，因而旱秧比水秧抗性增强，旱秧每穗籽粒干重与结实率一般高于水秧，旱秧移栽后在控水灌溉条件下有较大的增产潜力。     

实用转绿型叶色标记不育系白丰A的应用研究

用γ射线诱变Ⅱ32B干种子,筛选出苗期转绿型叶色突变体,并经回交选育,获得带转绿型叶色标记不育系白丰A。经考查,白丰A苗期第1~3叶表现叶片或叶缘白化,白化程度前2叶相对较高,4叶期开始转绿。该叶色突变性状受隐性单基因控制。白丰A主要花器性状和不育特性与Ⅱ32A相似,配合力仍保持Ⅱ32A的强优特点。不论稀播或密播,白丰A苗期生长均略慢于正常绿苗对照,但不会造成竞争致死。模拟杂交稻生产和制种繁种,表明利用苗期叶色标记结合人工去杂,可有效提高田间纯度。