一个新的水稻叶绿素缺失突变基因的遗传分析和分子标记定位

从正常绿色水稻品种824B中发现1个黄化突变体824ys。该突变体具有叶绿素缺失突变特性,表现为植株黄绿色,分蘖数减少,生育期延长,总叶绿素、叶绿素a、叶绿素b的含量以及净光合速率比野生型亲本824B明显下降,每穗着粒数、结实率、千粒重等降低。对824ys与3个正常绿色品种杂交F1、F2的遗传分析表明,控制824ys的叶绿素缺失突变性状为1对隐性核基因。以495R/824ys F2作为定位群体,应用微卫星标记将824ys的叶绿素缺失突变基因定位于水稻第3染色体短臂,与RM218、RM282和RM6959等标记之间的遗传距离分别为25.6、 5.2和21.8 cM。认为该基因为一个新的水稻叶绿素缺失突变基因,暂命名为chl11(t)。     

一个水稻颖壳扭曲突变体的遗传分析与基因定位

 从水稻育种后代材料中获得1个颖壳扭曲突变体Osth (twisted hull)。遗传分析结果表明,该突变性状由单核基因隐性突变造成。以突变体与颖壳正常籼稻R725杂交的F2群体为基因定位群体,利用SSR标记将突变位点定位在第2染色体上的SSR标记RM14128与RM208之间,遗传距离分别为1.4 cM 和2.7 cM。这些结果为该基因的精细定位和克隆以及研究水稻花发育的分子机理奠定了基础。     

Genetic Analysis and Mapping of TWH Gene in Rice Twisted Hull Mutant

A mutant with twisted hulls was found in a breeding population of rice (Oryza sativa L.). The mutant shows less grain weight and inferior grain quality in addition to twisted hulls. Genetic analysis indicated that the phenotype of mutant was controlled by a single recessive gene (temporarily designated as TWH). To map the TWH gene, an F2 population was generated by crossing the twh mutant to R725, an indica rice variety with normal hulls. For bulked segregant analysis, the bulk of mutant plants was prepared by mixing equal amount of plant tissue from 10 twisted-hull plants and the bulk of normal plants was obtained by pooling equal amount tissue of 10 normal-hull plants. Two hundred and seven pairs of simple sequence repeat (SSR) primers, which are distributed on 12 rice chromosomes, were used for polymorphism analysis of the parents and the two bulks. The TWH locus was initially mapped close to the SSR marker RM526 on chromosome 2. Therefore, further mapping was performed using 50 pairs of SSR primers around the marker RM526. The TWH was delimited between the SSR markers RM14128 and RM208 on the long arm of chromosome 2 at the genetic distances of 1.4 cM and 2.7 cM, respectively. These results provide the foundation for further fine mapping, cloning and functional analysis of the TWH gene.     

水稻着丝粒附近一个淡绿叶突变相关基因的定位分析

在T DNA插入水稻突变体库中,发现了一个以日本晴为遗传背景的温度钝感型淡绿叶突变体pgl2（pale green leaf 2 ）。遗传学分析表明该突变性状由1对单隐性核基因控制。利用突变体与籼稻品种龙特甫杂交,构建F2群体对突变基因进行精细定位。初步定位结果显示目的基因与第8染色体上SSR标记RM331连锁,在该标记附近发展了14对INDEL标记,将突变基因进一步定位于着丝粒上2.37 Mb的区间,并对该区间候选基因进行了分析。突变体叶绿素的总量与对照相仿,但是叶绿素a/b比值趋于1,明显低于对照。推测突变基因可能与叶绿素a、b间的转化有关。还就着丝粒中基因定位的引物设计方法进行了讨论。     

Genetic Analysis and Gene Mapping of a Rice Tiller Angle Mutant tac2

Tiller angle, a very essential agronomic trait, is significant in rice breeding, especially in plant type breeding. A tiller angle controlling 2 (tac2) mutant was obtained from a restorer line Jinhui 10 by ethyl methane sulphonate mutagenesis. The tac2 mutant displayed normal phenotype at the seedling stage and the tiller angle significantly increased at the tillering stage. A preliminary physiological research indicated that the mutant was sensitive to GA. Thus, it is speculated that TAC2 and TAC1 might control the tiller angle in the same way. Genetic analysis showed that the mutant trait was controlled by a major recessive gene and was located on chromosome 9 using SSR markers. The genetic distances between TAC2 and its nearest markers RM3320 and RM201 were 19.2 cM and 16.7 cM, respectively.     

一个水稻新黄绿叶突变体基因的分子定位

在水稻品种武运粳7号中发现了一个黄绿叶自然突变体,经过多代自交形成了稳定的突变系。该突变系和武运粳7号的正反交F2代的遗传分析表明该材料的黄绿叶由1对隐性基因控制,命名为 ygl 2。利用已有的微卫星（SSR）标记和新发展的SSR标记将 ygl 2基因定位于RM1340、RM7269、RM6298、SSR6 16和RM7434、SSR6 5、SSR6 9、RM5957之间,排列位置为RM1340-RM7269-RM6298-SSR6 16 -ygl 2-RM7434-SSR6 5、SSR6 9-RM5957,它们之间的遗传距离分别为238、0.37、0.00、0.62、0.74、0.49、0.86和1.62 cM,这为 ygl 2基因的分子标记辅助选择育种和图位克隆奠定了基础。     

水稻矮秆多分蘖突变体mz3的遗传分析和基因定位

通过EMS诱变粳稻品种中花11获得一个稳定遗传的矮秆多分蘖突变体mz3。遗传分析表明该突变性状受一对隐性基因控制,并利用mz3与籼稻品种南京11杂交建立的F2群体,将该基因定位在水稻第6染色体长臂上的SSR标记RM19353与RM510之间约747kb范围内。由于该区间包含控制水稻株高和分蘖的D3基因,结合表型分析,推测突变基因与D3可能为一对等位基因。设计7对引物分别对中花11与突变体mz3的基因进行测序,结果显示,与中花11相比,D3基因在mz3中第636位核苷酸由G突变为A,使得编码色氨酸的密码子TGG突变为终止密码子TGA,导致翻译提前终止。进一步对定位群体中10个隐性极端个体测序,结果显示所有极端个体都带有该突变位点。亚细胞定位结果表明,突变体编码的D3蛋白与野生型一样定位在细胞核中,荧光双分子互补试验结果表明,突变体D3蛋白不能与D14蛋白发生互作,推测突变体编码的D3截短蛋白缺少了与D14互作的氨基酸序列,从而阻碍了独脚金内酯信号传递。因此,mz3表型很可能由D3基因突变引起。     

水稻淡绿叶突变体HM133的遗传分析与基因定位

EMS诱导籼稻品种IR64获得淡绿叶突变体HM133。与野生型IR64相比,HM133播种后的第6周和第15周的光合色素含量以及抽穗期的净光合速率显著降低,气孔导度则明显上升;此外,突变体株高、每穗实粒数和结实率等农艺性状也较野生型显著下降。叶绿体超微结构分析表明,分蘖期HM133类囊体基粒片层形状不规则,堆叠凌乱、排列疏松。遗传分析表明HM133淡绿叶性状受单隐性核基因控制。通过分子标记将该基因定位于第3染色体长臂RM143和RM3684之间。该区间内包含编码镁螯合酶D亚基的基因OsCHLD。序列分析表明HM133中该基因第10外显子上有一个从G突变为A的单碱基变异,导致编码的氨基酸由精氨酸变成谷氨酸,推测OsCHLD基因即为控制HM133淡绿叶表型的候选基因。     

水稻显性小粒基因Mi3(t)的遗传定位

 对一份水稻小粒材料Y34进行了遗传研究及基因定位。Y34与长粒型水稻蜀恢881和蜀恢527的杂交F1表现为小粒，表明小粒性状受完全显性基因控制；同时，其F2群体小粒性状遗传分离规律均符合3∶1的分离比例，表明小粒性状受１对显性基因控制。利用蜀恢881/Y34 F2群体和微卫星标记，将该基因定位在第3染色体短臂上RM6283和RM282两个标记之间，其遗传距离分别为0.9 cM和5.1 cM，并将该基因初步命名为Mi3(t)。     

Genetic Analysis and Molecular Mapping of Light-Sensitive Red-Root Mutant in Rice

The light-sensitive red-root mutant, designated as HG1, was newly observed from an indica rice variety, Nankinkodo, when seedlings were grown with roots exposed to natural light. The root color of the mutant began to turn slight-red when the roots were exposed to the light at the intensity of 29 μmol/(m2·s), then turned dark-red at the light intensity of 180 μmol/(m2·s), suggesting that the root color of the mutant was evidently sensitive to light. Furthermore, genetic analysis showed that the character of ...     

Morphological Structure and Genetic Mapping of New Leaf-Color Mutant Gene in Rice (Oryza sativa)

Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white leaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 × Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.     

水稻色素原基因C的精细定位

应用籼稻组合珍汕97B/密阳46的衍生材料,针对水稻第6染色体短臂色素原基因C的可能位置,筛选到在C基因周围区间呈不同基因型组合的7个剩余杂合体,收获种子建立F2∶3群体。在各个植株上,稃尖颜色和叶鞘颜色的表现完全相同。通过各个群体颜色表现与原剩余杂合体基因型的比较,将C基因定位于微卫星标记RM314与RM253之间。在该基础上,应用两个分离群体共1279个样本,经标记检测和连锁分析,进一步将C基因定位于RM111和RM253之间, 与RM111和RM253的遗传距离分别为0.7 cM和0.4 cM。最后,应用区间内的另外6个微卫星标记和1个源于C基因候选基因OsC1的标记,检测在RM111 C基因 RM253区间内发生了重组的22个个体,将C基因定位于一个大小为59.3 kb、涵盖C基因候选基因OsC1座位的区间中。     

Fine Mapping of C(Chromogen for Anthocyanin)Gene in Rice

Seven residual heterozygous lines(RHLs)displaying different genotypic compositions in the genomic region covering probable locations of C (Chromogen for anthocyanin)gene on the short arm of rice chromosome 6 were selected from the progenies of the indica cross Zhenshan 97B/Milyang 46.Seeds were harvested from each of the seven plants,and the resultant F2:3 populations were used for fine mapping of C gene.It was shown in the populations that the apiculus coloration matched to basal leaf sheath coloration in each plant.By relating the coloration performances of the populations with the genotypic compositions of the RHLS,the C locus was located between rice SSR markers RM314 and RM253.By using a total of 1279 F2:3 individuals from two populations showing coloration segregation.the C locus was then located between RM111 and RM253,with genetic distances of 0.7 cM to RM111 and 0.4 cM to RM253.Twenty-two recombinants found in the two populations were assayed with seven more markers located between RM111 and RM253,including six SSR markers and one marker for the C gene candidate,OsC1.The C locus Was delimited to a 59.3-kb region in which OsC1 was located.     

水稻白条纹叶突变体st11的遗传分析与基因定位

白条纹叶突变体st11是从粳稻品种Kitaake组培过程中获得的。该突变体在分蘖前叶色表现为正常,从分蘖期开始新生叶表现为白条纹直至成熟期。与野生型相比,该突变体的分蘖、株高、结实率和千粒重等农艺性状没有发生明显变化。遗传分析表明该突变体白条纹叶性状受一对隐性核基因控制。利用该突变体分别与水稻02428、Jodan杂交构建了两个F2群体用于基因定位。通过集群分离分析(bulked segregant analysis)发现该基因位于第1染色体端粒附近,并与分子标记RM151和RM10080连锁。进一步利用更多分子标记分析F2群体,我们将该基因定位于I10和I26两个标记之间大约270kb的区间内。     

Genetic Analysis and Primary Mapping of pms4, a Photoperiod-Sensitive Genic Male Sterility Gene in Rice (Oryza sativa)

To understand the genetic characteristics of a new photoperiod-sensitive genic male sterile line Mian 9S,some reciprocal crosses were made between Mian 9S and six indica rice materials,Yangdao 6,Luhui 602,Shuihui 527,Mianhui 725,Fuhui 838 and Yixiang 1B.Genetic analysis results suggested that the photoperiod-sensitive genic male sterility (PGMS) of Mian 9S was controlled by a single recessive nuclear gene.Thus,the F2 population derived from the cross of Yangdao 6/Mian 9S was used to map the PGMS gene in Mian 9S.By using SSR markers,the PGMS gene of Mian 9S was mapped on one side of the markers,RM6659 and RM1305,on rice chromosome 4,with the genetic distances of 3.0 cM and 3.5 cM,respectively.The gene was a novel PGMS gene and designated tentatively as pros4.In addition,the application of the pros4 gene was discussed.     

Identification and Fine Mapping of a Gene Related to Pale Green Leaf Phenotype near the Centromere Region in Rice （Oryza sativa）

A thermo-insensitive pale green leaf mutant (pgl2) was isolated from T-DNA inserted transgenic lines of rice (Oryza sativa L. subsp. japonica cv. Nipponbare). Genetic analysis indicated that the phenotype was caused by a recessive mutation in a single nuclear-encoded gene. To map the PGL2 gene, an F2 population was constructed by crossing the mutant with Longtefu (Oryza sativa L. subsp. indica). The PGL2 locus was roughly linked to SSR marker RM331 on chromosome 8. To finely map the gene, 14 new InDel markers were developed around the marker, and PGL2 was further mapped to a 2.37 Mb centromeric region. Analysis on chlorophyll contents of leaves showed that there was no obvious difference between the mutant and the wild type in total chlorophyll (Chl) content, while the ratio of Chl a / Chl b in the mutant was only about 1, which was distinctly lower than that in the wild type, suggesting that the PGL2 gene was related to the conversion between Chl a and Chl b. Moreover, the method of primer design around the centromeric region was discussed, which would provide insight into fine mapping of the functional genes in plant centromeres.     

光照敏感型水稻红根突变体遗传分析及基因的分子定位

 在自然光条件下水培籼稻品种Nankinkodo中,发现根为红色的自然突变体,命名为HG1。水培条件下该突变体在光照强度大于29 μmol/（m2·s）的可见光下,根开始转红,在光照强度为180 μmol/（m2·s）的可见光下,呈鲜红,具有明显的光照敏感性。遗传分析表明,该突变体光照敏感性的红根性状由1对显性基因控制, 暂命名为Lsr。利用微卫星标记将Lsr基因定位在第4染色体上RM252与RM303之间,遗传距离分别为9.8 cM和6.4 cM, 这为Lsr基因的精细定位和克隆奠定了基础。     

水稻抗白背飞虱新基因Wbph6(t)的定位初报

应用由90个株系组成的TN1/鬼衣谷F3群体,分析了水稻抗白背飞虱新基因Wbph6 (t)与DNA标记的连锁关系。应用隐性极端群体法,将[WTBX][STBX]Wbph6[WTBZ][STBZ](t)定位于第11染色体短臂,与SSLP 标记RM167的遗传距离为21.2 cM。     

一个水稻金黄色颖壳和节间基因的遗传定位

R68是带有金黄色颖壳和节间标记的籼稻恢复系。对来源于组合中9A/R68 的F2群体的遗传分析表明,R68的金黄色颖壳和节间性状由1对隐性基因控制。利用SSR分子标记,采用隐性群体分析法,把金黄色颖壳和节间基因定位在第3染色体上,位于RM1230、RM7000和RM227、RM514之间,遗传距离分别为8.7、3.3、2.7和4.7 cM,暂将该基因命名为 gh 5。     

太湖流域粳稻地方品种黑壳子粳抗稻瘟病基因的分子定位

以广谱、高抗稻瘟病的太湖流域粳稻地方品种黑壳子粳与感病品种苏御糯杂交,产生F1、F2、F2∶3及F5∶6重组自交系群体,用日本稻瘟病鉴别菌系北1接种鉴定。黑壳子粳对北1的抗性是由1对显性主效基因控制的,定名为Pi hk1(t) 。根据不同杂交世代群体对北1的抗、感反应,结合SSR分子标记,将黑壳子粳中的Pi hk1(t) 基因定位在水稻第11染色体长臂末端,与RM7654和RM27381两个标记的遗传距离分别为0.9 cM和1.6 cM。