基因转化创造植物杂种优势利用新方式的途径分析

普通核雄性不育性遗传方式能够满足对植物最佳雄性不育系选育的要求,如果能解决其不育系繁殖问题,将优于现有的其他杂种优势利用方式。借助基因工程技术,通过质体转化、位点特异性重组技术和特殊启动子的利用,操控可育基因和不育基因的表达,可能繁殖出100%不育株率的普通核雄性不育系,创造出普通核雄性不育性利用新途径。     

分子标记鉴定红莲型细胞质雄性不育杂交水稻组合及其亲本

利用RAPD分子标记对红莲型细胞质雄性不育(HL—CMS)杂交水稻组合及其亲本进行了DNA多态性分析。从124个随机引物中筛选出具有非常明显的多态性，且只能扩增出1～5个片段的4个引物能有效地区分和鉴定红莲型(HL)2个杂交水稻组合(粤泰系列，从广系列)的杂种及其亲本。     

Advances in the understanding of inter-subspecific hybrid sterility and wide-compatibility in rice

Hybrid sterility is a major form of postzygotic reproductive isolation and frequently occurs in hybrids between divergent populations, such as the indica and japonica subspecies of Asian cultivated rice （Oryza sativa L.）. It has been a major barrier for utilization of the strong heterosis expressed in hybrids between indica and japonica. A large number of loci for rice inter-subspecific hybrid sterility have been identified by genetic analysis. Cytological studies revealed that male and female gamete abortions and reduced affinity between the uniting gametes all occurred in indica-japonica hybrids, suggesting the complexity of the causes for inter-subspecific hybrid sterility. Two genes conditioning embryo-sac and pollen sterility respectively in indica-japonica hybrids have been cloned recently, providing opportunities for molecular characterization of the indica-japonica hybrid sterility and wide-compatibility. Future studies should aim at cloning more genes for indica-japonica hybrid sterility, characterizing the underlying molecular mechanism, and utilization of the findings for the development of inter-subspecific hybrids to increase rice productivity.     

杂交粳稻二代利用的研究

<正> 几年来,杂交粳稻在我国北方迅速推广种植,对提高水稻产量起着积极作用,为我国北方水稻生产开创了一条新的途径。但是,种植杂交水稻需要年年制种,这样供种不好计划,例如制种过多,一则是用不完,二则因隔年种子往往保存不妥善,造成发芽率降低;若制种少了,则又不够用。为此,我们试图研究一个合理的解决办法。     

红莲型水稻不育系与保持系线粒体DNA酶切分析

为研究红莲型水稻细胞质雄性不育的分子基础，我们提取纯化了红莲型水稻丛广４１Ａ和丛广４１Ｂ的线粒体ＤＮＡ，采用限制性内切酶酶切片段长度多态性（ＲＦＬＰ）方法比较了红莲型不育系和保持系线粒体ＤＮＡ酶切图谱，发现两者之间存在一定的差异，部分支持了细胞质雄性不育与线粒体ＤＮＡ有关的结论。     

Construction and characterization of a bacterial artificial chromosome library of rice 5460F

Thermo-sensitive genie male sterile (TGMS) rice has a number of desirable characteristics for hybrid rice production. Many studies have demonstrated that the sterility of TGMS rice is controlled by a single recessive gene. It has been mapped for the first time on chromosome 8 and namedtms 1. Several AFLP markers which tightly linked to thetms 1 gene have been identified recently. In order to develop a detailed physical map of thetms1 gene-encompassing region and finally clone thetms1 gene, a bacterial artificial chromosome (BAC) library of rice 5460F (the fertile mutant line of TGMS rice 5460S) using a modified vector pECBAC1 has been constructed. The constructed 5460F BAC library consists of 16 896 clones with an average insert size of 119 kb, which represents about 4.7 times rice haploid genome equivalents. Neither chloroplast nor mitochondrial DNA was detected from the library. The library was screened with three single copy sequence amplified fragment length polymorphism (AFLP) markers which tightly linked totms1 gene as probes and eight positive clones were identified.     

杂交稻再生制种关键技术的探讨

在临桂宛田对杂交稻再生制种的关键技术进行了３年的试验研究，获得了最佳的技术条件，总结了一套适合当地杂交稻再生制种的技术。     

Restorable variation of cytoplasmic type of male sterile line in rice by in vitro culture

Rice male sterile (MS) lines, IR66707A and IR69700A, which possess the cytoplasm of Oryza perennis and O. glumaepatula respectively, belong to the cytoplasmic type. Their sterility could be maintained but not be restored. By somatic cell culture of these two MS lines, 47 somaclones with 465 R1 plants were obtained. All of the 465 R1 plants were sterile in the spring season in Guangzhou. According to the expression of the R1 plants and the level of similarity to their donor parents, they could be divided into three types. The plants of type Ⅰ were male sterile. The sterility of some somaclones of this type could be restored by the test crossing varieties or alternated to fertile by changes of some environmental conditions. The hybrid F1 of test cross from the MS somaclones in type Ⅰ was fertile while the hybrid F1 from the donor MS lines was still sterile. The R1 plants of type Ⅱ were similar to the donor parents and also male sterile. The hybrid F1 from all of the plants of type Ⅱ crossed to test variety were still sterile, so they did not possess restorability. For the somaclone of type Ⅲ, all of R1 plants were sterile in both male and female organs. No seed was set in both conditions of self and cross pollination. The fact that the restorable variants obtained in the cytoplasmic type of MS lines of rice by in vitro culture reported here should be the first sample in somaclonal variation in plant kingdom.     

Restorable variation of cytoplasmic type of male sterile line in rice byin vitro culture

Rice male sterile (MS) lines, IR66707A and IR69700A, which possess the cytoplasm of Oryza perennis and O. glumaepatula respectively, belong to the cytoplasmic type. Their sterility could be maintained but not be restored. By somatic cell culture of these two MS lines, 47 somaclones with 465 R₁ plants were obtained. All of the 465 R₁ plants were sterile in the spring season in Guangzhou. According to the expression of the R₁ plants and the level of similarity to their donor parents, they could be divided into three types. The plants of type Ⅰ were male sterile. The sterility of some somaclones of this type could be restored by the test crossing varieties or alternated to fertile by changes of some environmental conditions. The hybrid F₁ of test cross from the MS somaclones in type Ⅰ was fertile while the hybrid F₁ from the donor MS lines was still sterile. The R₁ plants of type Ⅱ were similar to the donor parents and also male sterile. The hybrid F₁ from all of the plants of type Ⅱ crossed to test variety were still sterile, so they did not possess restorability. For the somaclone of type Ⅲ, all of R₁ plants were sterile in both male and female organs. No seed was set in both conditions of self and cross pollination. The fact that the restorable variants obtained in the cytoplasmic type of MS lines of rice by in vitro culture reported here should be the first sample in somaclonal variation in plant kingdom.     

利用分子标记辅助选育香软型保持系“SH101B”、不育系“SH101A”及配组分析

为了给三系杂交稻新品种选育提供优良亲本,以"嘉花1号"水稻为转育亲本,与香型软米水稻杂交,再与"嘉花1号"水稻多代回交及自交,结合分子标记辅助选育香软型水稻新品系"SH101B"."嘉花1号"与"SH101B"水稻主要农艺性状和产量性状差异都不显著(p0.05)."SH101B"稻米直链淀粉含量(质量分数)为10.0%,明显低于"嘉花1号"水稻(15.2%).又将"SH101B"与三系不育系水稻杂交和回交,转育获得香软型三系不育系"SH101A",再与籼型恢复系"T201"进行配组,并对后代农艺性状、产量和稻米品质进行分析.结果显示,"SH101A×T201"组合稻米直链淀粉含量为12.8%,每亩产量达到848.1 kg(12 726.4 kg·hm~(-2)).     

会理县欧洲油葵杂交制种播种期和播种方式研究

以我国北方杂交油葵制种技术为基础,通过08、09两年在会理县进行欧洲油葵杂交制种试验研究,结果表明,制种时间应以春播为宜,采用育苗移栽方式,一期父本比母本提前9天播种,二期父本与母本同播可使父母本花期相遇;田间密度应略有加大,这样有利于提高会理县欧洲油葵杂交制种产量。     

杂交稻亲本始穗期与栽培条件关系的研究

本文研究了杂交稻制种中,营养生长阶段的栽培条件与亲本始穗期的关系,适宜的营养面积和空间与植株个体和群体生长势,花粉密度呈正相关。利用栽培技术来调节花期和花粉密度,对提高制种产量有重要作用。     

野栽远缘杂交来源的反向温敏核雄性不育系不育性遗传研究

利用3个来源于野生稻与栽培稻杂交后代的反向温敏不育系R6S、N13S、Tb7S为材料,开展了反向温敏不育系不育性遗传研究,结果表明反向温敏不育系N13S的育性是细胞核内1对隐性基因控制的;Tb7S的育性是受隐性核基因控制的,F2代的育性分离比为9∶7,不育性状表现为2对基因的独立遗传;R6S的F2代育性分离比为37∶27,受细胞核内的3个隐性基因位点分别位于不同染色体上而通过互补作用的独立遗传.为进一步分离、定位及克隆有关这些反向温敏不育基因及发展分子标记辅助选择选育反向温敏不育系奠定了良好的遗传学基础.     

抗广谱除草剂pursuit水稻的抗性遗传分析和利用

以4个恢复系测64、明恢63、特青和02428为母本,分别与抗除草剂pursuit(普杀特)水稻品种PT2杂交,遗传分析表明,PT2的抗性遗传符合一对显性核基因的模式.通过杂交一代和回交二代已将抗性基因转移到恢复系,初步培育出4个抗性恢复系测64-P、明恢63-P、特青-P和02428-P;它们与不育系杂交,选育到4个杂交稻组合.考种结果发现,抗除草剂组合基本上能保持原组合的产量水平,苗期喷药可完全淘汰假杂种.利用这项技术可望解决三系、两系或化学杀雄杂交稻制种过程中出现的纯度问题,且有利于新杂交稻组合的选育.对该项技术在生产上的应用前景和存在问题进行探讨.     

甘蓝型油菜细胞核雄性不育系“79.7”的遗传及应用研究

对雄性核不育油菜“79.7”作了遗传和应用研究。结果表明,“79.7”雄性不育油菜的不育特性是由两对隐性重叠基因控制的,甘兰型油菜可作它的恢复源。将“79.7”核不育油菜转育成新的低芥、双低及双低黄籽两用系.用低芥两用系组配筛选育成的优质杂交种“蜀杂1号”已在生产上大面积推广使用。     

Genetic rescue of inviable hybrids between Drosophila melanogaster and its sibling species

Post-mating mechanisms are central to the establishment of reproductive isolation between different, but closely related, species. Post-mating isolation mechanisms include hybrid breakdown, hybrid sterility and hybrid lethality and may, in some cases, be reinforced by pre-mating mechanisms such as ethological differentiation. In the Drosophila melanogaster species sub-group post-mating reproductive isolation is ensured by both the inviability and the sterility of hybrids. For example when D. melanogaster females are crossed to D. simulans males the hybrid progeny are normally all female; the hybrid males die as third instar larvae. The viable hybrid females are totally sterile. Little is known of the genetic basis for either hybrid sterility or hybrid inviability, although Coyne and others have begun a genetic analysis of the sterility of hybrids within this species sub-group. We have discovered a single gene difference that rescues the otherwise inviable male hybrids from the cross between D. melanogaster females and males of its three closest relatives. The study of this locus may shed light on the genetic control of both speciation and development.     

Identification and mapping of quantitative trait loci controlling cold-tolerance of Chinese common wild rice (O. rufipogon Griff.) at booting to flowering stages

Cold injury is an important limitation of rice production. Therefore, screening for cold-tolerant genetic resources and the development of highly cold-tolerant cultivars is crucial for higher yield potential and stable yield of rice. There have been several reports on the genetic analysis and QTL mapping of the cold-tolerance at the booting stage. Toriyama et al.[1,2] and Futsuhara et al.[3,4] reported that 4 or more genes were involved in the cold-tolerance. Several QTLs at the booting sta…     

Identification and mapping of quantitative trait loci controlling cold-tolerance of Chinese common with rice （O.rufipogon Griff.） at booting to flowering stages

An advanced backcross population of rice was used to identify the quantitative trait locus(QTL) controlling the cold-tolerance at booting to flowering stages.The recipient,Guichao 2(GC2),was a commercial Indica rice;the donor Dongxiang common wild rice,was an accession of common wild rice(DXCWR,Oryza rufipogon Griff.).Three QTLs for cold-tolerance were detected on chromosomes 1,6 and 11.Two of them coming from DXCWR could enhance the cold-tolerance of the backcross progenies.Moreover,one sterility QTL that could reduce the seed set rate of the backcross progenies by 78% was mapped on chromosome5.