辣椒雄性不育材料H9A小孢子败育机理

运用光学、电子显微技术及生化指标测定法, 对辣椒（Capsicum annuum）雄性不育材料H9A及其保持系H9B小孢子不同发育时期进行细胞形态学观察及生化特性分析。结果表明, 雄性不育材料H9A的小孢子败育发生在单核前期, 由于绒毡层细胞极度膨胀, 四分体受挤压后破裂并降解, 无法形成正常的单核花粉粒, 属于孢子体败育。不育材料花蕾中的过氧化物酶活性从四分体时期开始明显高于保持系, 保持系游离脯氨酸含量从单核小孢子期开始明显高于不育材料; 不育材料小孢子发育各时期的可溶性蛋白含量都明显低于保持系, 但丙二醛含量均高于保持系。     

辣椒雄性不育材料H9A小孢子败育机理

运用光学、电子显微技术及生化指标测定法, 对辣椒(Capsicum annuum)雄性不育材料H9A及其保持系H9B小孢子不同发育时期进行细胞形态学观察及生化特性分析。结果表明, 雄性不育材料H9A的小孢子败育发生在单核前期, 由于绒毡层细胞极度膨胀, 四分体受挤压后破裂并降解, 无法形成正常的单核花粉粒, 属于孢子体败育。不育材料花蕾中的过氧化物酶活性从四分体时期开始明显高于保持系, 保持系游离脯氨酸含量从单核小孢子期开始明显高于不育材料; 不育材料小孢子发育各时期的可溶性蛋白含量都明显低于保持系, 但丙二醛含量均高于保持系。     

辣椒雄性不育材料小孢子发生的细胞形态学观察

用石蜡切片技术,在光学显微镜下观察了辣椒雄性不育材料1A及其保持系1B的小孢子发育过程和各时期的形态特征.结果表明,雄性不育材料1A的小孢子败育发生在四分体至单核花粉粒时期,此时绒毡层细胞异常肥大,四分体受到挤压后破裂并降解,无法形成正常的单核花粉粒.扫描电镜观察结果表明,保持系1B的花粉粒结构完整,表面有3个明显的萌发沟;而雄性不育材料1A的成熟花粉粒形状不规则,空瘪,有部分花粉粒解体,败育比较彻底,说明该雄性不育材料在辣椒育种工作中有较高的利用价值.     

不结球白菜雄性不育系及其保持系花药发育的细胞学观察

以不结球白菜（Brassica campestris ssp．chinensis Makino）雄性不育系及其保持系为试验材料,选择不同发育阶段的花蕾,取其花药,制成石蜡切片和超薄切片,经染色后在电子显微镜下观察。结果表明,不结球白菜雄性不育系与保持系的花药发育有明显的不同：不育系花药发育受阻于花粉母细胞分化期,形成1～3个药室,并形成正常的四分体小孢子,此时细胞组织逐步解体,形成空腔花药;最后向内皱缩;保持系花粉母细胞能形成正常的四分体,进而形成小孢子,最终形成充满正常花粉粒的花药。     

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％.     

雄性不育和雄性能育小麦(Triticum aestivum L.)花药和花粉发育的细胞形态学观察

本工作是小麦雄性不育杂种优势利用研究项目的一部分。从细胞形态学的角度,研究小麦细胞质雄性不育系及其保持系花药和花粉的发育,为探索雄性不育性的机理提供资料。应用石蜡切片法,对小麦“早熟1号”和“北京8号”细胞质雄性不育系及其保持系花药的发育过程进行了观察,得到如下的结果:(1)不育系花粉的败育,在发育的各个时期都发生,但败育的关键时期是在小孢子发育后期,具大液泡的小孢子不能进入配子体发育阶段。(2)不育系花药和花粉的发育,在小孢子发育早期以前,90%以上与保持系相似,是正常的;少数表现异常而导致败育。异常现象有:药室合并;小孢子母细胞解体,绒毡层发育正常;小孢子母细胞互相粘连,形成多核的原生质团;解体的小孢子母细胞与绒毡层融合形成多核的原生质团;药室中除正常发育的小孢子母细胞或小孢子外,还出现异常的巨型细胞;绒毡层提早在小孢子发育早期解体,形成多核的原生质困;绒毡层肥大生长。     

红菜薹雄性不育系花药败育的细胞形态学观察

采用石蜡切片技术,在光学显微镜下系统研究了红菜薹(Brassica campestris L.ssp．chinensis L.var．utilis TsenetLee．)波里马胞质雄性不育系(Polima CMS)、红菜薹萝卜胞质雄性不育系(Ogura CMS)及相应保持系花药发育过程的细胞形态学特征。观察结果表明：红菜薹Polima CMS花药发育受阻于孢原细胞阶段,不形成花粉,属无花粉型,此不育系花药不形成绒毡层和中层;而红菜薹Ogura CMS花药败育发生于小孢子母细胞期或四分体时期,表现为绒毡层细胞异常,挤压四分体,导致四分体和绒毡层同时解体而败育。     

萝卜CMS不育系与保持系小孢子发生的细胞学研究

研究了萝卜胞质雄性不育系A2、A4及其相应保持系B2、B4的小孢子发生与花药壁发育的细胞学特征.结果表明,不育系A2的绒毡层细胞在四分体时期出现异常,小液泡增多,至单核期汇合形成大液泡,绒毡层细胞异常膨大;小孢子外壁染色浅,细胞壁受到破坏,最后与绒毡层一同降解.不育系A4在减数分裂期即表现出异常,绒毡层异常肥大;花药发育后期,小孢子外壁亦染色较浅;绒毡层细胞融合形成细胞团块侵入药室挤压小孢子,两者一同降解.     

芝麻核雄性不育系ms86-1微粉发生的细胞学观察

芝麻(Sesamum indicum)核雄性不育系ms86-1姊妹交后代表现为可育、部分不育(即微粉)及完全不育(简称不育)3种类型。不同育性类型的花药及花粉粒形态差异明显。Alexander染色实验显示微粉植株花粉粒外壁为蓝绿色, 内部为不均一洋红色, 与可育株及不育株花粉粒的染色特征均不相同。为探明芝麻微粉发生机理, 在电子显微镜下比较观察了可育、微粉、不育类型的小孢子发育过程。结果表明, 可育株小孢子母细胞减数分裂时期代谢旺盛, 胞质中出现大量脂质小球; 四分体时期绒毡层细胞开始降解, 单核小孢子时期开始出现乌氏体, 成熟花粉时期花粉囊腔内及花粉粒周围分布着大量乌氏体, 花粉粒外壁有11–13个棱状凸起, 表面存在大量基粒棒, 形成紧密的覆盖层。不育株小孢子发育异常显现于减数分裂时期, 此时胞质中无脂质小球出现, 细胞壁开始积累胼胝质; 四分体时期绒毡层细胞未见降解; 单核小孢子时期无乌氏体出现; 成熟花粉时期花粉囊腔中未发现正常的乌氏体, 存在大量空瘪的败育小孢子, 外壁积累胼胝质, 缺乏基粒棒。微粉株小孢子在减数分裂时期可见胞质内有大量脂质小球, 四分体时期部分绒毡层发生变形, 单核小孢子时期有部分绒毡层开始降解; 绒毡层细胞降解滞后为少量发育进程迟缓的小孢子提供了营养物质, 部分小孢子发育为正常花粉粒; 这些花粉粒比较饱满, 表面有少量颗粒状突起, 但未能形成覆盖层, 花粉囊腔中及小孢子周围存在少量的乌氏体。小孢子形成的育性类型与绒毡层降解是否正常有关。     

辣椒细胞质雄性不育花药败育及淀粉粒分布的细胞学观察

用PAS反应对辣椒细胞质雄性不育系8214A和保持系8214B花药中的淀粉粒分布进行研究.在减数分裂前,保持系花药与不育系花药的结构和淀粉粒分布相似.保持系花药减数分裂后,药壁绒毡层细胞开始液泡化并体积增大,在药隔薄壁细胞中积累了许多较小的淀粉粒;在小孢子晚期,绒毡层细胞退化,在药隔薄壁细胞中淀粉粒体积增大;在二胞花粉时期,随着花粉大液泡的消失花粉中出现淀粉粒;花粉成熟时,其细胞质中积累了丰富的淀粉粒.不育系花药减数分裂后,由于药室腔的空间不能扩大,四分体被挤压在一起,最终四分体小孢子败育.不育花药的维管组织发育正常,但较多的淀粉粒积累在药隔薄壁细胞中.该种辣椒雄性不育系中.花粉的败育发生在四分体时期.绒毡层细胞结构异常可能影响糖类物质向药室的正常转运.该种辣椒雄性不育系的绒毡层异常与花粉败育有关.     

Abnormal Vacuolization of the Tapetum During the Tetrad Stage is Associated with Male Sterility in the Recessive Genic Male Sterile <Emphasis Type="Italic">Brassica napus</Emphasis> L. Line 9012A

In the recessive genic male sterile line 9012A of Brassica napus, pollen development is affected during the tetrad stage. According to the light and electron microscopy analysis of tapetal cells and tetrads, the sterile tapetal cells swelled with expanded vacuoles at the early tetrad stage and finally filled the center of the locules where a majority of tetrads encased with the thick callose wall collapsed and degraded. We suggested that an absence of callase, which is a wall-degrading enzyme stored in the vacuoles of tapetal cells before secretion, resulted in the failure of tetrad separation. Moreover, transmission electron microscopy analysis showed that the secretory tapetal cells were not observed in sterile anthers, which indicated that the transition of the tapetum from the parietal type to the secretory type was probably aberrant. In plants, degeneration of the tapetum is thought to be the result of programmed cell death (PCD). PCD of tapetal cells was investigated by terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay and signals indicative of deoxyribonucleic acid fragmentation were detected much earlier in sterile anther than in fertile anther. This suggests that tapetal breakdown does not occur by the normal procession of PCD and might be following an alternative mechanism of unscheduled apoptosis in line 9012A. This research supports the hypothesis that premature PCD is associated with male sterility in B. napus.     

水稻胞质雄性不育系珍汕97A及其保持系珍汕97B绒毡层发育过程中的Ca2+分布变化

利用焦锑酸钾沉淀法研究了野败不育系珍汕97A及其保持系珍汕97B绒毡层细胞的发育过程及其细胞中Ca2 的分布变化。研究发现保持系绒毡层细胞在单核花粉晚期才开始迅速解体,而不育系绒毡层细胞在花粉母细胞时期就开始出现核膜、细胞膜解体,此过程持续到二核花粉时期。珍汕97A绒毡层细胞从花粉母细胞时期开始,细胞质内有少量颗粒状的Ca2 沉淀;减数分裂时期,绒毡层细胞的内切向壁表面有大量大颗粒的Ca2 沉淀;单核花粉时期绒毡层细胞周围集聚一层Ca2 沉淀。而保持系绒毡层细胞遮花粉母细胞时期和减数分裂时期细胞内没有Ca2 沉淀;单核花粉时期绒毡层细胞内的Ca2 沉淀主要分布在解体的细胞质内。推测绒毡层细胞结构发育的异常和Ca2 的异常分布可能与花粉的败育有关。     

Ethylene is Involved in the Control of Male Gametophyte Development and Germination in Petunia

The time courses of 1-aminocyclopropane-1-carboxylic acid (ACC) content and ethylene production in developing anthers of petunia fertile and sterile lines and the effects of exogenously applied ethylene and an inhibitor of ethylene action, 2,5-norbornadiene (NBD), on male gametophyte development and germination were investigated. Fertile male gametophyte development was accompanied by two peaks of ethylene production by anther tissues. The first peak occurred during microspore development simultaneously with degeneration of both tapetal tissues and middle layers of the anther wall. The second peak coincided with maturation and dispersal of pollen grains. The mature pollen is characterized by a high ACC content (up to 300 nmol/g). Exogenously applied ethylene (1–100 ppm) induced degradation of gametophytic generation at the meiosis stage. NBD completely inhibited anther development at the early stages of its development and delayed anther dehiscence. In anther tissues of the petunia sterile line, tenfold higher ethylene production was observed at the meiosis stage compared to that in fertile male gametophytes and this correlated with degeneration of both microsporocytes and tapetal tissues. In vitro male gametophyte germination was accompanied by an increase of ethylene production, whereas NBD completely blocked male gametophyte germination. These results suggest that ethylene is an important factor in male gametophyte development and germination.     

Differences on the microsporogenesis and tapetal development of male fertile and cytoplasmic male sterile pepper (Capsicum annuum L.)

To clarify the time and cause of pollen abortion, differences on the microsporogenesis and tapetum development in the anthers of male fertile maintainer line and cytoplasmic male sterile (CMS) line pepper were studied using transmission electron microscopy. The results showed that CMS line anthers appeared to have much greater variability in developmental pattern than male fertile maintainer line ones. The earliest deviation from normal anther development occurred in CMS line anthers at prophase I was cytomixis in some microspore mother cells (MMCs), and vacuolisation in tapetal cells. Then, MMCs in CMS line anthers developed asynchronously and a small part of ones at the different stage degenerated in advance appearing to have typical morphological features of programmed cell death (PCD). Most MMCs could complete the meiosis, but formed non-tetrahedral tetrad microspores with irregular shape and different size and uncertain number of nuclei, and some degenerated ahead of time as well. Tapetal cells in CMS line anther degenerated during meiosis, and were crushed at the tetrad stage, which paralleled the collapse of pollens. Pollen abortion in CMS line anthers happened by PCD themselves, and the premature PCD of tapetal cells were closely associated with male sterility.     

新型甘蓝型油菜温敏核不育系SP2S的花药发育解剖学观察

SP2S是西北农林科技大学选育的甘蓝型油菜温敏核不育系,本文采用半薄树脂切片、扫描电镜对SP2S及其可育近等基因系SP2F的花药发育及花粉形态进行观察比较,发现SP2S花药发育在减数分裂时期出现异常,单核花粉时期彻底败育。其主要特征是：减数分裂时期绒毡层已经径向肥大且出现大液泡,胼胝质不能及时降解,使得单核小孢子相互粘连在一起,小孢子无花粉壁的形成且细胞质物质逐渐降解,最后小孢子仅剩下空壳残留物,聚集在一起。SP2S败育特征与现有的核不育材料不同,表明其有可能是一种新型温敏核不育材料。     

Cytochemical investigation of genic male-sterility in Chinese cabbage

A genic male sterile Chinese cabbage, Brassica campestris L. ssp. chinensis Makino, was examined using cytological and cytochemical methods to characterize the process of pollen abortion in this plant. Thick sections of both fertile and sterile anthers at different developmental stages were stained using Toluidine Blue O, Periodic Acid-Schiff’s (PAS) reaction and Sudan Black B to detect cytochemical changes that may occur in the distribution of insoluble polysaccharide and lipid storage bodies. Pollen abortion in sterile anthers occurs at an early stage of microspore development. During early microspore development, reductions in the number of starch grains in the connective tissue of fertile anthers coincide with the accumulation of starch grains in cells of the anther wall. In the late microspore stage, a large vacuole forms in the microspore, and tapetal cells synthesize and accumulate lipid droplets. The cellular organization of tapetal cells in sterile anthers appears similar to that in fertile anthers, except for the absence of lipid droplets in cells of sterile anthers and diffusely labeled tapetal polysaccharides, suggesting defects in nutrient storage. Supported by National Natural Science Foundation of CHINA (30170060)     

大白菜雄性败育的显微结构观察

通过对核质互作型雄性不育系169A和核雄性不育两用系88_3的细胞形态解剖学观察表明,两个不育系在开花时雄性细胞均表现100%的败育,花药的表皮细胞均具有生活力,但败育形式、时期、特点各异。169A败育发生于孢原细胞前后,以孢原细胞退化,或转变成薄壁细胞为主要特点。88_3败育从小孢子母细胞至二核花粉粒皆有发生,高峰期在四分体前后（约占80%）,小孢子母细胞不能进入减数分裂和不能完成减数分裂及小孢子不能正常发育是败育的主要形式,但败育特点均是败育一旦发生便是急剧而彻底的解体或凝集成一团。