一份条斑和颖花异常水稻双突变体的形态特征和细胞学观察

在水稻遗传转化过程中发现一个不含外源基因的条斑和颖花异常的双突变体。该突变体的茎、叶、穗出现条斑。在分蘖盛期,一些叶片开始分岔或卷曲;花器官数目增多,表现为多内外稃,叶片状浆片,或浆片增大,雌雄蕊增多,颖花开裂。透射电镜对叶片白色组织细胞超微结构观察,发现细胞壁内陷,质体结构异常,不能发育出正常叶绿体所具有的片层和类囊体。叶绿素总含量和净光合速率明显低于野生型。突变体绿色组织部分中的细胞生长正常,但细胞较大。利用扫描电镜对花器官形态发生过程进行观察,雄蕊原基发育严重不同步,原基大小也不一样;心皮原基较小。     

植物D型细胞周期蛋白

D型细胞周期蛋白(cyclinD,CycD)调控着细胞周期G1/S的转换,基本过程为CycD在外界环境刺激下积累,并与周期蛋白依赖激酶(cyclin-dependentkinase,CDK)形成有活性的激酶,促进成视网膜细胞瘤蛋白(retinoblastoma,Rb)磷酸化,使E2F因子释放,由此促使G1/S转换,这一调控系统在高等真核生物中具有很高的保守性。CycD与其他细胞周期蛋白表达有所不同,其受到生长因子的强烈诱导,去掉生长因子后,表达水平迅速下降,导致细胞被抑制在G1期。大量研究表明,CycD是细胞周期中一个关键的“感受因子”,CycD基因的表达是细胞周期进程中的限速因子,影响着植物的生长发育。现对植物CycD的特征以及在细胞周期中的功能进行综述,并探讨了其在植物生长发育中的作用。     

水稻分子标记辅助育种及其前景

总结了水稻分子标记辅助育种的主要内容,其技术体系和研究进展被详细地加以介绍。同时,根据其发展趋势也介绍了水稻分子标记辅助育种的前景。     

水稻寡分蘖突变体的遗传分析和基因定位

从籼粳交组合“圭630/02428”的花培后代中获得一份寡分蘖突变体G069,其主要特征是分蘖速度慢,最高分蘖数少,成熟叶片叶尖、叶缘黄化.用突变体作母本与02428杂交,并以02428作轮回亲本与杂交后代突变型单株回交构建BC₂F₂.对BC₂F₂进行调查和遗传分析,确认突变体G069寡分蘖特性和叶片黄化现象受同一隐性基因控制.以BC₂F₂分离群体为基础,应用SSR标记和RFLP标记进行连锁分析,将寡分蘖基因定位于第2染色体的RFLP标记C424和S13984之间,分别相距2.4和0.6cM.该基因暂定名为ft1.     

抗虫基因转化优良籼型保持系D297B的研究

本文报道了用基因枪法将雪花莲外源凝集素基因(gna)转移到优良籼型杂交稻保持系D297B中。通过PCR、Southern blotting和Western blotting等分子检测方法证明,外源基因已整合到受体材料的基因组中并得到表达。蛋白活性测定结果显示转基因在受体中表达的蛋白具有生物活性。潮霉素抗性分析表明外源基因多数是以单位点形式整合并以3∶1方式遗传。另外,PCR证据也说明抗虫基因与选择标记基因基本上是共整合和共遗传的     

Genetic analysis and gene mapping of a rice few-tillering mutant in early backcross populations ( Oryza sativa L.)

A rice mutant,G069, characteristic of few tiller numbers, was found in anther culture progeny from theF ₁ hybrid between anindica-japonica cross, Gui630×02428. The mutant has another two major features: delayed tillering development and yellowing apex and margin on the mature leaves. As a donor parent,G069 was further backcrossed with the recurrent parent,02428, for two turns to develop aBC ₂F₂ population. Genetic analysis in theBC ₂F₂ population showed that the traits of few-tillering and yellowing apex and margin on the mature leaves were controlled by one recessive gene. A pool of equally mixed genomic DNA, from few-tillering individual plants inBC ₂F₂, was constructed to screen polymorphism with simple sequence repeat (SSR) markers in comparison with the02428 genome. One SSR marker and three restriction fragment length polymorphism (RFLP) markers were found possibly linked with the recessive gene. By using these markers, the gene of few-tillering was mapped on chromosome 2 between RFLP marker C424 and S13984 with a genetic distance of 2.4 cM and 0.6 cM, respectively. The gene is designatedft1.     

萍乡显性核不育水稻育性相关基因的定位和遗传分析

萍乡显性核不育水稻(Pingxiang Dominant Genic Male Sterile Rice,PDGMSR)是在水稻中首次发现的显性核不育材料,其育性由两对显性基因互作控制,一对是萍乡显性核不育基因Ms-p,另一对是显性上位恢复基因(dominant epistatic fertility restorer gene,Rfe)。两者共同存在时显性上位恢复基因能抑制不育基因的表达,从而使育性表现可育。本实验用一个对萍乡显性核不育水稻有恢复能力的水稻品种E823与萍乡显性核不育水稻配制杂交组合,将(萍乡核不育水稻/E823)F2作为定位群体,根据F3株系的育性分离,选择育性分离株系对应F2单株(基因型为Ms-pMs-pRefrfe和Ms-pms-pRferfe)构建可育池,用对应F2株系中的不育单株(基因型为Ms-pMs-prferfe或Ms-pms-prferfe)构建不育池,将显性上位恢复基因Rfe定位在水稻10染色体RM311和RM3152一侧,遗传距离分别为7.9cM和3.6cM。根据已有的Ms-p的定位结果,合成10染色体部分微卫星引物,对不育单株进行分析,发现RM171和RM6745位于Ms-p的两侧,距离分别为0.3cM和3.0cM。根据10染色体的测序结果,将Ms-p界定在约730kb的范围内,并构建了Ms-p的电子重叠群。植物显性核不育的育性恢复机理存在“复等位基因”和“显性上位互作”两种假说,贺浩华等用经典的遗传学方法证明了萍乡显性核不育水稻育性恢复的遗传机理属于“显性上位互作”。理论上认为,确定其遗传机理最为有效的方法是基因定位,如果不育基因和恢复基因位于同一位点,则其遗传机理属于“复等位基因”,否则为“显性上位互作”。本实验将不育基因和恢复基因定位在水稻10染色体不同的位点,用基因定位的方法证实了萍乡显性核不育水稻育性恢复的遗传机理属于“显性上位互作”。     

Genetic analysis and gene mapping of a rice few-tillering mutant in early backcross populations (Oryza sativa L.)

A rice mutant, G069, characteristic of few tiller numbers, was found in anther culture progeny from the F1 hybrid between an indica-japonica cross, Gui630×02428. The mutant has another two major features: delayed tillering development and yellowing apex and margin on the mature leaves. As a donor parent, G069 was further backcrossed with the recurrent parent, 02428, for two turns to develop a BC2F2 population. Genetic analysis in the BC2F2 population showed that the traits of few-tillering and yellowing apex and margin on the mature leaves were controlled by one recessive gene. A pool of equally mixed genomic DNA, from few-tillering individual plants in BC2F2, was constructed to screen polymorphism with simple sequence repeat (SSR) markers in comparison with the 02428 genome. One SSR marker and three restriction fragment length polymorphism (RFLP) markers were found possibly linked with the recessive gene. By using these markers, the gene of few-tillering was mapped on chromosome 2 between RFLP marker C     

稻瘟病菌无毒基因研究进展

水稻与稻瘟病菌之间的特异互作符合基因对基因假说。本文将从稻瘟病菌与水稻抗病基因间的互作特点、稻瘟病菌的分子标记、已克隆的稻瘟病菌无毒基因三个方面对稻瘟病菌无毒基因研究进展作简要介绍     

水稻(Oryza sativa L.)苗期低温白化突变体al12的超微结构与基因定位

水稻苗期低温白化突变是水稻在发育早期对低温胁迫的一种适应性,是一种受发育和温度控制的条件表达,它与其他水稻白化突变有本质的不同.本研究利用便携式叶绿素测量仪测定了白化时期植株的叶绿素含量和用透射电镜观察了叶绿体的结构变化.结果发现叶绿素平均含量仅为1.2(SPAD),而叶绿体也不能正常发育仅有囊泡状结构.通过与9311的正反交实验及子代的分离表现证明该性状受一个隐性核基因的控制.另外利用SSR分子标记技术将该基因定位在第8染色体上,两侧最近的SSR标记RM5068和RM3702分别距基因0.5～1.1 cM和4.9 cM,基因被定位在约6个cM的区间内.我们将该基因暂时命名为al12.