高秆突变体Mh-11的株高遗传研究

Mh-11是从矮秆品种桂朝2号辐射诱变后代中产生的高秆突变体.用Mh-11与sd-11矮秆、非sd-11矮秆和普通高秆材料杂交,通过对F1、F2、F3 等世代以及测交后代的株高进行遗传分析,结果表明Mh-11的高秆特性是由1对隐性抑制基因控制的.该抑制基因能调节sd-11基因的表达,而对由非sd-11基因控制的矮秆没有抑制作用,这一隐性抑制基因暂时被定名为i-sd-11(t).还讨论了该基因的遗传学意义和可能的育种利用价值.     

水稻半矮秆基因sd－g的染色体定位研究

以标志基因系和ＩＲ３６三体为工具材料,通过杂交,研究了籼稻矮秆材料双矮所携半矮秆基因ｓｄ－ｇ在染色体上的位置。结果表明：半矮秆基因ｓｄ－ｇ与标志基因系Ｍ４所携隐性主基因ｇｈ－１和Ｍ２７所携隐性主基因ｎ１表现连锁。ｓｄ－ｇ与ｇｈ－１之间的交换值为２４．３３％±３．９６％,ｓｄ－ｇ与ｎ１之间的交换值为２９．４４％±４．８１％。由于ｇｈ－１和ｎ１均位于第５染色体,因而推定ｓｄ－ｇ位于第５染色体上。     

具广亲和性的水稻隐性高秆细胞突变体

０２４２８ｈ系粳稻隐性高秆细胞突变体。来源于半矮秆广亲和种质０２４２８体细胞无性系变异。在１０３个Ｒ２代株系中,有１株系在抽穗后分离出高、矮秆两种类型,高秆比矮秆高６１．４％,系因例一和倒二节间伸长所致,以倒一节间伸长最为明显,占增长的６６．３％。在Ｒ３、Ｒ４代中矮秆类型继续分离出高秆和矮秆两在型,分离比为３：１,高秆类型未见分离。显示所分离的高秆是供体亲本０２４２８的单基因突变。暂名为０２４２８     

棉花矮化突变体的遗传分析

陆地棉科遗２号×中棉完紫的种间杂交衍生后代群体中分离出一株矮秆小叶突变体,经多年选择育成了矮早棉１号。在北京气候条件下,矮早棉１号成熟时,株高只有４５ｃｍ,不到正常陆地棉的１／２。遗传分析揭示矮早棉１号的矮化早熟特性系由两对隐性基因控制,其基因符号定名为ｄ_１和ｄ_２,矮早棉１号为双隐性纯合子,基因型为ｄ_１ｄ_１ｄ_２ｄ_２。正常陆地棉ＴＭ－１、中棉所１２及中棉所１６均为显性纯合子,基因型为Ｄ_１Ｄ_１Ｄ_２Ｄ_２。控制棉花株高的两对基因Ｄ_１／ｄ_１和Ｄ_２／ｄ_２间表现重叠作用。矮早棉１号在棉花早熟育种中有重要价值。     

中国大麦矮秆种质资源的基因分析：Ⅰ.矮秆遗传和等位测验

了２４份中国大麦矮秆种质资源的株高遗传,在它们的矮秆基因之间且与已矮秆基因ｕｚ、ｓｄｗ、ｂｒ和ｅｎｓｏ进行遗传等位性测验。结果表明,这些矮秆种在多隐性单基因遗传,少数受隐性基因控制,只有１份携带１对隐性和１对不完全显性筹秆基因。     

水稻半矮秆基因sd-t的染色体定位研究

以籼型标志基因系和ＩＲ３６三体为工具材料,通过杂交研究了籼稻矮秆材料矮泰引－２所携半矮秆基因Ｓｄ－ｔ在染色体上的位置。结果表明,半矮秆基因Ｓｄ－ｔ与标志基因系０１９所携紫果皮基因Ｐｒｐ－ｂ、标志基因系Ｂ３０所携无叶舌基因１ｇ、标志基因系０２７所携灰白壳基因Ｗｈ表现连锁,ｓｄ－ｔ与Ｐｒｐ－ｂ之间的交换值为２．８５％±０．５２％,ｓｄ－ｔ与ｌｇ之间的交换值为２７．９０％±３．８１％,ｓｄ－ｔ与Ｗｈ之间的交换值为３８．６２％±２．９９％。由于Ｐｒｐ－ｂ、ｌｇ、Ｗｈ基因均位于第４染色体上,因而推定ｓｄ－ｔ基因位于第４染色体上,其排列位置可能是Ｐｒｐ－ｂ－ｓｄ－ｔ－ｌｇ－Ｗｈ。     

水稻长穗颈高秆隐性基因eui2的遗传及其微卫星分析

从水稻（Oryza sativa L.)协青早Ｂ的辐射Ｍ２群体中获得以最上节间伸长特征的长穗颈高秆突变系协青早eB-1和协青早eB-2,与原品系协青早Ｂ的秆性状相比,协青早eB-2的第一节间长占总秆长的６５．３％,其第一节间的增长量占秆长总增长量的９０．２％;协青早eB-1的第一节间长占总秆长的５４．８％,其第一节间的增长量占秆长总增长量的５３．３％,遗传分析表明：协青早eB-2中的长穗颈高秆性状各由一对隐性基因控制,二之间互不等位。与已报道的eui基因的等位性测验表明：协青早eB-２的eui基因与其不等位,为新的长穗颈高秆隐性基因,命名为eui2,协青早eB-１的eui基因则与其等位。微卫生分析表明：eui2基因与第１０第染色体的ＲＭ２５８、ＲＭ２６９、ＲＭ２７１和ＲＭ３０４连锁,其遗传距离分别为１２．０cM、１２．９cM、３５．１cM、１．４cM。由此推断,eui2基因位于第１０染色体长臂的中部。     

应用混合分布模型研究水稻株高的遗传

用质量－数量性状的混合分布遗传模型对２个水稻矮秆×高秆的Ｆ_２群体（组合１：Ｈ３５９／Ａｃｃ８５１８;组合 ２：Ｈ３５９／Ａｃｃ８５５８）的株高遗传进行了研究．结果表明：１）存在 １对主基因的分离,高秆对矮秆完全显性; ２）这对主基因的效应大小在两个组合中非常相近,说明这对主基因在不同遗传背景中效应稳定,与微基因之间无明显互作,这对于育种应用是有利的;３）两组合中由微基因分离引起的遗传方差大小相近,微基因的平均显性效应皆是减效方向,且数值上也相近,而平均加性效应则皆呈增效方向,但数值上相差很大,说明两组合中发生分离的微基因的数目可能相似,但微基因在双亲间的分布情况却大不相同;４）亲本表型方差（亦即环境方差）与亲本均值呈明显正相关关系,高秆的环境方差要比矮秆大得多,因而在不同主基因型中,微基因的遗传力表现不同,这在育种实践中应引起注意．     

不同籼稻品种的矮生性与内源ABA水平及其结合蛋白的关系

试验研究了内源脱落酸及其结合蛋白与含有不同矮秆主基因的籼稻矮生性状的关系。结果表明：籼稻的矮生性也受内源ＡＢＡ及其结合蛋白协同调控。矮秆品种幼苗内源ＡＢＡ及其幼芽膜上ＡＢＡ结合蛋白水平显著高于离秆品种,且含有强矮化效应的ｓｄ－ｇ基因的新桂矮、双矮的内源ＡＢＡ及其结合蛋白水平又明显高于含ｓｄ－１半矮秆基因的广场矮。外源ＡＢＡ能显著抑制籼稻幼苗伸长,苗高下降率与ＡＢＡ结合蛋白水平有一定的关系,且矮秆品     

三个矮杆小麦的矮生性遗传研究

通过与事国春杂交,利用杂交后代Ｆ２和回交后代ＢＣ１Ｐ１及ＢＣ２Ｐ２,研究了三个小麦新矮杆品系和矮生性遗传特性。结果表明,０００４的矮生性受一对部分显性矮杆基因控制,５７４６和７５３９－各受两对部分显性矮杆基因控制。     

粳稻矮秆品种苗期和成株期对赤霉素反应的研究

本试验对28个粳稻矮秆品种对GA3的反应进行了研究,结果表明粳稻矮秆品种对GA3反应较为复杂,苗期与成株期反应,大多数品种表现为趋势基本一致,但也存在着其它种类型表现;在粳稻中,对GA3反应敏感的矮秆品种并不一定携带含有sd-1等位基因,但含有sd-1基因的品种表现为敏感,不含有sd-1基因的表现为低敏感或不敏感,据此可以初步确定矮4和紫叶矮含有与sd-1非等位的矮秆基因,是一种新的矮源;GA3对株高构成因素的影响表现因品种不同而异,但以基部一、二节间为主.     

Genetic mapping of a new semi-dwarf gene, sd-t(t), in indica rice and estimating of the physical distance of the mapping region

Application and functional study of dwarf and semi-dwarf genes are of great importance to both crop breeding and molecular biology. A new semi-dwarf gene, sd-t(t), non-allelic to sd-1, had been identified in an indica rice variety, Aitaiyin 2. In this study the gene was genetically mapped by using an F2 population, which consisted of 474 individuals developed from a cross between Aitaiyin 2 and B30. The sd-t(t) gene was located between the RFLP markers R514 and R1408B with a distance of 1.1 cM to R514, and 4.5 cM to R1408B on chromosome 4. A physical contig covering the sd-t(t) mapping region was further constructed by screening a BAG library with R514 and R1408B as probes, and the physical distance between R514 and R1408B was estimated at approximately 147 kb. This result will facilitate map-based cloning of the sd-t(t) gene.     

水稻半矮生基因sd—1的遗传性状表现：Ⅲ.半矮生与穗粒数的结合

半矮生基因ｓｄ－１有抗倒伏和改善株型的效果,广泛存在于世界各地的水稻丰产品种中,最近发现该基因具有减少穗长和千粒重的副作用。为澄清此副作用,能否通过遗传背景的改良得以克服,进而培育成粳稻型的半矮生大穗品咱,本研究用高秆品种农林２９号及其半矮生纯合系ＳＣ－ＴＮ１和大穗品种Ａｋｅｎｏｈｏｓｈｉ的杂种进行了分析。用Ｆ４代系统的实验结果表明,半矮生系统的穗长较高秆系统的为小。但是,由于半矮生系统的枝梗数。     

Identification and genetic analysis of semidwarfism-related proteins in rice (Oryza sativa L.)

Summary By transferring a semidwarf gene (sd-1) from Taichung Native 1 into a tall Japanese cultivar, Norin 29, through seven backcrosses, a semidwarf near-isogenic line SC-TN1 was obtained. The proteins of the embryo in Norin 29 and SC-TN1 were separated by two-dimensional electrophoresis. Most of the proteins showed the same electrophoretic pattern. However, it was found that there was a difference in the appearance of two basic glycoproteins designated as SRP-1 and SRP-2. These proteins exhibited the same molecular mass, but different isoelectric points. Hybridization results indicated that a single locus controls SRP-1 and SRP-2 with codominant alleles. The gene symbol Srp was given to this locus, with alleles Srp-1 and Srp-2 responsible for SRP-1 and SRP-2, respectively. Srp-2 was found in all of the semidwarf cultivars and lines having sd-1, except a tall cultivar Tsaiyuan-chung. This finding suggests that Srp-2 may be closely linked with sd-1. The amounts of these proteins markedly increased after water absorption of the seed, suggesting that these proteins may be related to the early development of the plant.     

Identification, genetic characterization, GA response and molecular mapping of Sdt97: a dominant mutant gene conferring semi-dwarfism in rice (Oryza sativa L.)

Semi-dwarfism is an important agronomic trait in rice breeding programmes. sd-1, termed the 'Green Revolution gene', confers semi-dwarf stature, increases harvest index, improves lodging resistance, and is associated with increased responsiveness to nitrogen fertilizer. It has contributed substantially to the significant increase in rice production. In this paper, a novel semi-dwarf mutant in rice is reported. Genetic analysis revealed that only a single dominant gene locus non-allelic to sd-1, temporarily designated Sdt97, is involved in the control of semi-dwarfism of the mutant. The semi-dwarfism of the mutant could be partly restored to the tall wild-type by application of exogenous GA3, suggesting that the mutant gene Sdt97 may be involved in the gibberellin (GA) synthesis pathway and not the GA response pathway in rice. A residual heterozygous line (RHL) population derived from a recombinant inbred line (RIL) was developed. Simple sequence repeat (SSR) and bulked segregation analysis (BSA) combined with recessive class analysis (RCA) techniques were used to map Sdt97 to the long arm of chromosome 6 at the interval between two STS markers, N6 and TX5, with a genetic distance of 0.2 cM and 0.8 cM, respectively. A contig map was constructed based on the reference sequence aligned by the Sdt97 linked markers. The physical map of the Sdt97 locus was defined to a 118 kb interval, and 19 candidate genes were detected in the target region. This is the first time that a dominant semi-dwarf gene has been reported in rice. Cloning and functional analysis of gene Sdt97 will help us to learn more about molecular mechanism of rice semi-dwarfism.     

水稻长穗颈基因eui紧密连锁SSR标记获得

02428h是从半矮秆材料02428体细胞培养后代中发现的隐性高秆突变体, 其株高性状由1对长穗颈基因eui和1对半矮秆基因sd-1共同控制。以02428h与半矮秆材料南京11杂交的F₂为作图群体, 利用Gramene公布的SSR标记和根据NCBI中的BAC序列自己新开发的SSR标记, 将eui基因定位在第5染色体上的RM3673和RM0012之间, 两侧遗传距离分别为0.3 cM和1.0 cM, 为该基因的分子标记辅助选择奠定了基础。     

Genetic mapping of a new semi-dwarf gene, <Emphasis Type="Italic">sd-t(t)</Emphasis>, in indica rice and estimating of the physical distance of the mapping region

Application and functional study of dwarf and semi-dwarf genes are of great importance to both crop breeding and molecular biology. A new semi-dwarf gene, sd-t(t), non-allelic to sd-1, had been identified in an indica rice variety, Aitaiyin 2. In this study the gene was genetically mapped by using an F₂ population, which consisted of 474 individuals developed from a cross between Aitaiyin 2 and B30. The sd-t(t) gene was located between the RFLP markers R514 and R1408B with a distance of 1.1 cM to R514, and 4.5 cM to R1408B on chromosome 4. A physical contig covering the sd-t(t) mapping region was further constructed by screening a BAC library with R514 and R1408B as probes, and the physical distance between R514 and R1408B was estimated at approximately 147 kb. This result will facilitate map-based cloning of the sd-t(t) gene.     

Two non-allelic nuclear genes restore fertility in a gametophytic pattern and enhance abiotic stress tolerance in the hybrid rice plant

In indica rice, the HongLian (HL)-type combination of cytoplasmic male sterility (CMS) and fertility restoration (Rf) is widely used for the production of commercial hybrid seeds in China, Laos, Vietnam and other Southeast Asian countries. Generally, any member of the gametophytic fertility restoration system, 50% of the pollen in hybrid F(1) plants displays recovered sterility. In this study, however, a HL-type hybrid variety named HongLian You6 had approximately 75% normal (viable) pollen rather than the expected 50%. To resolve this discrepancy, several fertility segregation populations, including F(2) and BC(1)F(1) derived from the HL-CMS line Yuetai A crossed with the restorer line 9311, were constructed and subjected to genetic analysis. A gametophytic restoration model was discovered to involve two non-allelic nuclear restorer genes, Rf5 and Rf6. The Rf5 had been previously identified using a positional clone strategy. The Rf6 gene represents a new restorer gene locus, which was mapped to the short arm of chromosome 8. The hybrid F(1) plants containing one restorer gene, either Rf5 or Rf6, displayed 50% normal pollen grains with I(2)-KI solution; however, those with both Rf5 and Rf6 displayed 75% normal pollens. We also established that the hybrid F(1) plants including both non-allelic restorer genes exhibited an increased stable seed setting when subjected to stress versus the F(1) plants with only one restorer gene. Finally, we discuss the breeding scheme for the plant gametophytic CMS/Rf system.     

New sources of dwarfing genes in pearl millet (Pennisetum americanum)

Summary Thirteen naturally occurring dwarf lines of pearl millet [Pennisetum americanum (L.) Leeke], identified from the world collection, varied for several morphological and agronomic characters. Extreme dwarfs were characterized by a tufted growth habit which could be distinguished from the time of germination, while the other dwarf lines could be distinguished only after anthesis. The F₁ hybrids between the tall and dwarf genotypes were tall, indicating that dwarfness is a recessive trait. In 10 out of the 13 crosses, the F₂ segregation ratio was three tall to one dwarf (31) suggesting that the dwarfness is controlled by a single recessive gene, while the height differences in 3 of the dwarfs (IP 8056, IP 8210 and IP 8214) were controlled by more than one gene as they showed continuous variation for plant height in F₂. When the remaining 10 single gene dwarfs were crossed to either d ₁ (Tift 238) or d ₂ (Tift 23 DB) dwarfs, only 2 crosses produced tall F₂ hybrids and they segregated for height in F₂ indicating that these 2 dwarfs are non-allelic to d ₁ and d ₂. Reciprocal crosses of these 2 dwarfs produced tall F₁ hybrids and showed a dihybrid segregation of 934 in F₂ indicating that the dwarfing genes of these 2 parents are non-allelic to each other. These non-allelic dwarfs were assigned the gene symbols d ₃ (IP 10401), and d ₄ (IP 10402).Submitted as J.A. No. 429 by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT)     

水稻Dwarf1移码突变的新突变体鉴定

从一批水稻品种"中花11"组织培养苗里分离到一个矮化突变株"C6PS",它的T2代群体株高呈现3:1分离。利用该群体矮化单株与"珍汕97"、"牡丹江8"构建2个F2群体F2(CZ)、F2(CM),两个群体中高株与矮株均呈现3:1分离,证明该性状变异为单基因控制。"C6PS"表现型与已经报道的Dwarf1隐性突变体"d1"相似,以D1附近标记RM430检测F2(CZ)群体基因型,结果显示群体表型与RM430基因型呈极显著相关(P=0.0001),将该基因初步定位于Dwarf1附近。对"C6PS"及"中花11"进行D1序列分析显示,突变株中D1基因在其第九个外显子与第九个内含子的剪接位点上发生6个碱基的缺失,根据缺失两侧序列设计C6PS-D1L/R标记,在T2代群体该标记与表型呈现共分离,表明"C6PS"是一种新的Dwarf1突变体。cDNA测序显示突变体d1基因转录产物发生26个碱基的缺失,导致移码产生终止突变,从而无法翻译出有功能的Gα蛋白,因此,它是一个Gα功能缺失突变体。叶倾斜度检测显示"C6PS"对油菜素内酯响应比野生型"中花11"弱。