两份太空诱变玉米雄性不育突变体的遗传研究

从搭载神舟4号飞船的4份玉米自交系后代中选育出两份雄性不育突变体, 对其进行育性鉴定, 并分析不育性状的稳定性及遗传特点。以不育材料的不育株为母本, 同群体的可育株和其他自交系为父本进行杂交, 结合自交、回交分析其后代的育性表现; 同时, 以具有正常细胞质的自交系为母本, 育性完全恢复的测交F1植株为父本进行反交, 对其反交的F1及F2进行育性观察分析。结果表明：这两份不育材料不育株的花药内无花粉或含少量畸形花粉, 败育彻底, 花粉败育表现为典败型。不育性状在不同年份、不同季节、不同地点下稳定遗传, 属可遗传的单基因控制的隐性核不育类型。     

太谷核不育小麦花药内游离脯氨酸和总氨基酸含量的变化及其与育性的关系

本文对显性单基因控制的太谷核不育小麦不同发育阶段的可育株和不育株的花药及雌蕊内游离肺氨酸和游离总氨基酸的含量进行了分析。结果表明:(1)在小孢子母细胞减数分裂期,不同育性花药之间游离脯氨酸的含量无明显差异,且含量较低。(2)在小孢子单核初期,可育花药内游离脯氨酸的含量显著高于不育花药,是不育花药的7倍,比减数分裂期增加20倍,高达其干重的1.65％,占其游离总氨基酸的50％。(3)在雌蕊中,游离脯氨酸的含量远远低于花药,不同育性植株之间差异不很明显。(4)关于游离总氨基酸的含量,在花药中减数分裂期,不同育性植株之间无明显差异;在小孢子单核初期,可育株高于不育株。在雌蕊中,相应于小孢子单核初期时,可育株稍高于不育株,受精后迅速趋于一致,但整个变化幅度不大。     

太谷核不育小麦不育株花药败育过程中核酸代谢的异常现象

太谷核不育小麦,从小孢子母细胞减数分裂期开始,不育株花药的核酸代谢就有明显异常,核糖核酸(RNA)含量很低,仅为可育株花药的22％,而游离单磷酸尿苷(UMP)含量则高于可育花药4倍左右。不同育性花药中RNA聚合酶活力无明显差别。RNA水解酶活力表现异常,如其组成酶中新酶n带的出现和原有各组成酶相对活力不同程度的提高等。可育株和不育株旗叶的核酸含量无明显差别。     

湖北光敏感核不育水稻不育性的遗传规律

本文选用5个常规粳稻品种和3小光敏感核不育系与湖北光敏感核不育水稻农垦58S杂交,用花粉育性、套袋自交结实率、自然结实率和大田目测4种育性指标同时鉴定同一植株育性,观察分析杂种后代在长日下植株育性的表现。结果表明：光敏核不育水稻不育性的遗传行为表现为受1对隐性主基因控制,不同的遗传背景对不育性的遗传行为表现有不同程度的影响。     

桔梗雄性不育花药的发育解剖学研究

通过田间观察和石蜡切片法对桔梗不育和可育花药的形态及其解剖结构进行了比较研究,结果表明:桔梗可育和不育花器形态、花药长度无明显差异,而开花后,可育花药饱满、有光泽、有花粉粒散出,不育花药皱瘪、无光泽、无花粉粒散出;不育花药绒毡层提前退化解体,导致小孢子发育异常。     

水稻雄性不育与可育花药的mRNA差别显示和cDNA差别片段的分析

用mRNA差别显示 ,对水稻细胞质雄性不育系、保持系和F1杂种的花药mRNA和叶片mRNA进行了比较和分析 ,以研究雄性不育花药在花粉败育时期的基因表达方式 .花药在不育与可育间显示的cDNA差别带数多于叶片 ,表明在花药中育性基因的表达比叶片中活跃和充分 .不同类型花药的基因转录方式既与花药育性程度有关也与花药败育早晚有关 ,不育、部分不育和早期败育的花药所显示的cDNA差别带数多于可育和晚期败育的花药 .在回收的 1 2个cDNA差别片段中 ,有2个可能与雄性不育相关 ,AB₄A₅ 片段只在不育花药中专一表达 ,另一片段AB₃ B₂ 含有与线粒体基因coxⅡ同源的序列 ,在不育花药中的表达受到部分抑制     

大白菜新型细胞质雄性不育系6w-9605A的育性鉴定和花药败育的细胞学观察

采用石蜡切片技术,研究了大白菜(Brassica campestris L.ssp.pekinensis)细胞质雄性不育系6w-9605A及其保持系6w-9605B的花药发育过程的细胞形态学特征,确定不育系花药败育时期及方式,并对不育系6w-9605A进行花器官观察和育性鉴定.结果表明:保持系6w-9605B花药发育正常;不育系6w-9605A花药发育受阻于孢原分化时期,占总败育花药的66.7％,不形成花粉囊和花粉粒,属于无花粉囊型败育;另外33.3％的败育花药可形成花粉囊,小孢子均受阻于单核靠边期或者二胞期,败育特点为绒毡层细胞异常肥大,挤压小孢子,导致小孢子和绒毡层解体;6w-9605A的不育性稳定、彻底,不育株率和不育度均为100％.     

空间环境诱发玉米细胞质雄性不育突变体的遗传分析

从返回式卫星"实践八号"搭载的08-641和18-599两份玉米自交系后代选育出3份雄性不育突变体,在不同地点、不同年份、不同季节进行种植观察,鉴定其育性表现,通过测交、反交及回交对不育性状的遗传特性进行分析。结果表明:3份不育突变材料均能稳定遗传,属可遗传的细胞质雄性不育类型。恢保关系测定和特异引物PCR扩增结果显示,3份不育材料均属玉米C型细胞质雄性不育类型,但3份不育材料在恢保关系上存在一定差异,推测它们可能分别属于玉米C型细胞质雄性不育的不同亚组。这些不育材料的发现,丰富了雄性不育胞质的遗传基础,在玉米不育化制种中具有一定应用价值。     

茄子雄性不育系花粉败育的细胞学观察

以种间杂交创建的茄子雄性不育系为试材,采用形态学和细胞学观察对其花药形态、败育发生时期和机理进行了研究。结果表明：根据花药形态茄子雄性不育系材料可被划分为退化型、瓣化型和中间型3种类型;前期Ⅰ是3类不育系雄性败育发生的关键时期,绒毡层结构与功能异常可能是导致3类材料雄性败育的共性原因,减数分裂异常为败育的中间过程。花药瓣化类型不育材料在败育时期上表现出多样性,多糖类营养物质转运受阻也可能是其发生雄性败育的原因之一。     

水稻亚种间杂种是否存在雌性不育？

水稻亚种间杂种不育性是一种普遍现象,但其遗传基础复杂。目前在亚种间杂种不育遗传上,不同研究的结论不尽一致,即使对亚种间杂种不育性主要表现为雄性不育还是雌性不育也存在争论。本对证明水稻亚种间杂种存在和不存在雌性不育的研究进行了综述与分析。从中可以看出无论是认为水稻亚种间杂种不育性表现为雄性不育还是雌性不育的结论都有一定的片面性,尤其是Sano证明基因座S－5不存在的研究存在较大的缺陷。因此,水稻亚种间杂种雌雄配子败育对小穗育性影响的大小有待进一步研究。     

Antisense inhibition of a nuclear gene,BrDAD1, in Brassica causes male sterility that is restorable with jasmonic acid treatment

Male sterility is widely used for the production of hybrid seeds, but the use of genic male sterility is rather limited because of difficulty in maintaining homozygous male sterile plants. Recently, the DEFECTIVE IN ANTHER DEHISCENCE 1 (DAD1) gene, which encodes a phospholipase A1 involved in the first step of the jasmonic acid (JA) biosynthesis pathway, was isolated from a male sterile Arabidopsis mutant. To utilize this gene in Brassica crops, we characterized the BrDAD1 gene, the putative ortholog of DAD1 in Brassica rapa. Out of 25 plants transformed with an antisense gene constructed from the BrDAD1, 3 plants showed a defect of anther dehiscence at the flower bud opening stage and produced inviable pollen. One of the three showed male sterility only, but the other two showed a delay or a lack of flower opening in addition to male sterility. The male sterile and flower-opening phenotypes were rescued by the application of JA as well as linolenic acid. Furthermore, all these characteristics were inherited to the next generation. The present results demonstrate a novel control system for hybrid seed production by the use of nuclear genes.     

Production of transgenic male sterile tobacco plants with the cDNA encoding a ribosome inactivating protein in Dianthus sinensis L.

The ribosome inactivating protein (RIP) gene from D. sinensis was used as a cytotoxin gene to induce male sterility in tobacco plants. The TA29 promoter, obtained by PCR amplification from tobacco, was fused to the RIP cDNA, and the chimaeric molecule was then introduced into tobacco plants by Agrobacterium-mediated transformation. Out of twenty-one independent transformants, twenty transgenic tobacco plants exhibited male sterility. Southern blot analysis revealed that four of the transgenic plants contained a single copy of the RIP gene, while the rest of the transgenic tobacco plants had two to four copies of the gene. The transgenic male sterile plants set seeds normally when pollinated with pollens from untransformed control plants, indicating that the RIP gene does not affect the pistil development. Furthermore, the seed yield of the transgenic plant was similar to that of the untransformed, self-pollinated control plant. A light microscopic observation of anther cross sections clearly showed that the tapetal tissue of the anther was selectively and completely destroyed causing male sterility. This study suggests that the RIP gene can be used as a cytotoxin gene for induction of male sterility in the plant.     

太空诱变玉米核不育突变体矮化的遗传及外施赤霉素分析

为了解太空诱变玉米核不育突变体矮化的遗传规律和原因,该研究以不育突变体为母本,自交系178、478为父本,对测交 F1、F2群体进行育性鉴定和株高分析,对 F2可育株进行基因型和株高分析,对姊妹交后代分离群体进行育性鉴定和株高、雄穗长度、节间数、节间长度分析,同时,还对姊妹交后代分离群体进行施赤霉素处理,调查育性和株高的变化。结果表明：178和478背景下的 F1表现出与测交母本一样的极显著差异;在178和478核背景下的 F2中,不育株株高极显著矮于可育株,两核背景下的不育株间株高差异不显著,而可育株间株高差异极显著;F2中纯合和杂合可育株的株高差异不显著;姊妹交后代分离群体中不育株株高、雄穗长度、节间数和节间长度极显著小于可育株;外施赤霉素的不育株在苗期表现出对赤霉素一定的敏感性,但株高最终未恢复正常高度。因此,得出该突变体矮化表现稳定,与不育性状并存,且不受细胞核背景的影响;核不育基因对植株株高的矮化无剂量效应;突变体的矮化与雄穗长度、节间数和节间长度有关;突变体不完全属于赤霉素不敏感型,其矮化并不是单一缺乏赤霉素而引起。该研究结果为认识太空诱变玉米核不育突变体矮化的遗传和生理机制提供了参考。     

Development of a novel recessive genetic male sterility system for hybrid seed production in maize and other cross‐pollinating crops

We have developed a novel hybridization platform that utilizes nuclear male sterility to produce hybrids in maize and other cross‐pollinating crops. A key component of this platform is a process termed Seed Production Technology (SPT). This process incorporates a transgenic SPT maintainer line capable of propagating nontransgenic nuclear male‐sterile lines for use as female parents in hybrid production. The maize SPT maintainer line is a homozygous recessive male sterile transformed with a SPT construct containing (i) a complementary wild‐type male fertility gene to restore fertility, (ii) an α‐amylase gene to disrupt pollination and (iii) a seed colour marker gene. The sporophytic wild‐type allele complements the recessive mutation, enabling the development of pollen grains, all of which carry the recessive allele but with only half carrying the SPT transgenes. Pollen grains with the SPT transgenes exhibit starch depletion resulting from expression of α‐amylase and are unable to germinate. Pollen grains that do not carry the SPT transgenes are nontransgenic and are able to fertilize homozygous mutant plants, resulting in nontransgenic male‐sterile progeny for use as female parents. Because transgenic SPT maintainer seeds express a red fluorescent protein, they can be detected and efficiently separated from seeds that do not contain the SPT transgenes by mechanical colour sorting. The SPT process has the potential to replace current approaches to pollen control in commercial maize hybrid seed production. It also has important applications for other cross‐pollinating crops where it can unlock the potential for greater hybrid productivity through expanding the parental germplasm pool.     

Genetics of Male Sterility in Gynodioecious Plantago Coronopus. II. Nuclear Genetic Variation

Inheritance of male sterility was studied in the gynodioecious species Plantago coronopus using five plants and their descendants from an area of ~50 m(2) from each of four locations. In each location, crosses between these five plants yielded the entire array of possible sex phenotypes. Both nuclear and cytoplasmic genes were involved. Emphasis is placed on the nuclear (restorer) genetics of two cytoplasmic types. For both types, multiple interacting nuclear genes were demonstrated. These genes carried either dominant or recessive restorer alleles. The exact number of genes involved could not be determined, because different genetic models could be proposed for each location and no common genetic solution could be given. At least five genes, three with dominant and two with recessive restorer allele action, were involved with both cytoplasmic types. Segregation patterns of partially male sterile plants suggested that they are due to incomplete dominance at restorer loci. Restorer genes interact in different ways. In most instances models with independent restorer gene action were sufficient to explain the crossing results. However, for one case we propose a model with epistatic restorer gene action. There was a consistent difference in the segregation of male sterility between plants from the two cytoplasmic types. Hermaphrodites of cytoplasmic type 2 hardly segregated male steriles, in contrast to plants with cytoplasmic type 1.     

在杂交作物分子育种中利用普通核雄性不育的几个可能途径

由一对隐性基因控制的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,是水稻等作物杂种优势利用的极好遗传工具。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。克隆出普通核雄性不育性的可育基因,通过叶绿体转化,将核雄性不育性可育基因向普通核雄性不育株细胞质转移,创造普通核雄性不育株的保持系;通过种子成熟后表达的启动子;和以位点特异性重组技术为基础的基因开关以及化学诱导启动子的利用,都可能繁殖出100%不育株率的普通核雄性不育系,创造普通核雄性不育性利用的新途径,对植物杂种优势利用产业有十分重要的意义。     

TA29-barnase基因转化菜心

利用根癌农杆菌导入法, 以菜心带柄子叶为外植体, 对TA29-barnase基因转化菜心进行研究。获得转化植株,进行PCR、Southern blotting杂交和半定量RT-PCR检测, 表明目的基因已经整合到转化植株中, 并且目的基因在转基因植株花蕾中得到表达, 但是表达水平在不同转基因植株间存在差别; 转基因植株开花后, 均表现雄性不育, 不能产生花粉或产生没有活力的少量花粉, 自交不能结实; 用未转化植株正常花粉对雄性不育植株进行授粉, 能够正常结实; 保持系(未转化植株)与不育株杂交后代中雄性不育株与可育株的比例为1:1, 在杂交后代植株子叶期, 喷洒10 mg/L的PPT可以完全杀死可育株; 利用其他菜心品种为父本与不育株进行杂交, 获得的F1植株在生长势和产量方面表现优势, 表明开展菜心优势育种具有一定的潜力。