水稻印尼水田谷型细胞质雄性不育恢复系R68的恢复基因初步定位

用印尼水田谷型不育系中9A和恢复系R68配组,选取F2的高可育株和极端不育株构建2个基因池,用82个完全不育单株作为定位群体,利用分布于12条染色体的413对SSR引物对双亲和两池进行多态性分析。 位于第1染色体的RM283和位于第10染色体的RM5756、RM258、RM6100、RM171 在亲本、两池间存在多态性,用F2单株验证证明它们与恢复基因连锁。经典遗传分析和分子标记定位研究表明,印尼水田谷型细胞质雄性不育恢复系R68具有2对恢复基因,分别位于第1和第10染色体上。位于第1染色体的恢复基因与分子标记RM283的距离是6.7 cM,位于第10染色体的恢复基因与标记RM5756、RM258、RM6100和RM171间的距离分别是10.4、8.0、2.4和4.2 cM。     

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。     

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。     

粳稻野败型细胞质雄性不育恢复系SWR78的恢复基因定位

 利用野败(WA)型粳稻广亲和不育系苏秋A和广亲和广谱型恢复系SWR78配组,根据F2与BC1F1群体的育性分离情况,初步推测WA型苏秋A的育性恢复至少由3对基因控制。选取F2群体中无染色花粉植株,采用隐性基因组分析法进行恢复基因定位,将其中1个主效基因Rf4定位于第10染色体长臂上,与标记RM5629、RM5373、STS10 17和STS10 18分别相距0.17、0.03、0.03和0.07 cM。Rf4位于标记RM5373与STS10 17之间,两标记间的物理距离为78 kb。     

水稻第1染色体短臂粒长和粒宽QTL的精细定位

以第1染色体短臂RM1-RM3746和RM151-RM243区间内呈杂合、背景基本纯合的2个水稻剩余杂合体（RHL）衍生两个F6群体,将控制水稻粒长和粒宽的2个粒形QTL（qGL 1和qGW 1）定位于RM3746-RM243区间内。在此基础上,应用SSR标记检测,从其中1个群体中筛选到杂合区间分别为RM151-RM10404、RM10398-RM5359、RM10435-RM259和RM10381-RM243的4个单株,应用SSR标记进一步检测4套F2群体,从每套F2群体中分别筛选到母本珍汕97B和父本密阳46纯合型材料各10株,自交获得4套近等基因系材料并考查其粒长和粒宽。利用交迭重组染色体片段代换系分析法,将控制粒长和粒宽的QTL （qGL 1和qGW 1）界定于437.5 kb的RM10390-RM1344区间和392.9 kb的RM10376-RM10398区间,增效等位基因均来自母本珍汕97B,表明qGL 1和qGW 1是紧密连锁的不同座位。     

水稻矮败型细胞质雄性不育恢复基因的定位

 在由210个测交组合组成的协青早A/(协青早B/密阳46)F6群体中，应用RFLP和SSLP标记，在第10染色体RZ811～RG561区间，定位了1个控制水稻矮败型细胞质雄性不育育性恢复的主效基因，与RZ811相距 4.0 cM，对群体变异的贡献率为 43.2%。应用极端群体分析法，其定位结果一致。     

水稻第6染色体短臂上株高QTL qPH6-1的精细定位

 应用衍生于水稻剩余杂合体的分离群体,开展株高QTL的检测和精细定位。应用1个在水稻第6染色体短臂约7.3 Mb区间分离、背景基本纯合的F2:3群体,种植于海南、浙江两地,检测到2个控制株高的QTL;然后,针对两地间作用稳定的qPH6 1,筛选出3个杂合区间缩小且呈阶梯状排列的单株,衍生F2群体,进一步验证了qPH6 1的作用,并将其界定于距离为96.4 kb的SSR标记RM3414和RM19417之间;最后,应用分离区间进一步缩小且呈阶梯状排列的3个F2群体,将qPH6 1定位于距离为51.7 kb的STS标记Si2925和SSR标记RM19417之间。基因组位置比较结果显示,该基因与所有已定位或克隆的水稻矮秆、半矮秆基因均非等位。     

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)。     

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)。     

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.     

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 F_2:3 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 F_2:3 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.     

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。     

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.     

Mapping of Rice Fertility-Restoring Genes for ID-Type Cytoplasmic Male Sterility in a Restorer Line R68

An F2 population derived from the cross Zhong 9NR68 was used to map the fertility-restoring (Rf) gene for ID-type cytoplasmic male sterility (CMS).Two bulks (a fertile bulk and a sterile bulk) were constructed by pooling equal amount of ten highly fertile lines and ten highly sterile lines,respectively.Four hundred and thirteen pairs of simple sequence repeat (SSR) primers,which evenly distributed on 12 chromosomes of rice,were selected for analyzing polymorphisms between the parents and between the two bulks.The primer RM283 on chromosome 1 and the primers RM5756,RM258,RM6100 and RM171 on chromosome 10 were found to be polymorphic between the parents and between the two bulks.These five SSR markers were linked to fertility-restoring genes.A total of 82 excessive sterile lines were selected from Zhong 9NR68 F2 population to estimate the genetic distance between five SSR markers and fertility-restoring genes respectively.The results indicated that one Rf gene was linked to RM283 located on chromosome 1 at a distance of 6.7 cM,and the other Rfgene was mapped to the long arm of chromosome 10 flanked by RM258 and RM6100 at the distances of 8.0 cM and 2.4 cM,respectively.     

Genetic Analysis and Mapping of Dominant Minute Grain Gene Mi3（t） in Rice

Grain size, determined chiefly by grain length, is one of the main factors affecting the grain yield in rice production. To study the trait of rice grain size, F1 and F2 populations were developed from crosses Shuhui 881/Y34 and Shuhui 527/Y34, and genetic analysis for minute grain was performed. The F1 populations showed minute grains, and grain size segregations in the two F2 populations were both in accordance with the ratio of 3：1, indicating that minute grain in Y34 was controlled by a completely dominant gene. By using the F2 population from Shuhui 881/Y34, this dominant gene, tentatively designated as Mi3（t）, was mapped based on SSR markers in the interval between RM282 （genetic distance of 5.1 cM） and RM6283 （genetic distance of 0.9 cM） on the short arm of chromosome 3.