东亚千里光族款冬亚族的花部微观性状及其系统与分类学意义

所研究的东亚款冬亚族及其相关类群的花部微观性状主要包括:花药顶端不育组织、花药药室内壁、花药基部、花药领、花柱分枝顶端、花柱毛被、花柱分枝内表面构型和果柄细胞列数等。此外, 根据所获证据, 讨论了款冬亚族花部微观性状的演化趋势。花部微观性状研究表明:毛冠菊属似乎应作为紫菀族中的一个孤立属;狗舌草亚族与千里光亚族和款冬亚族相比, 似乎是一过渡类群;东亚款冬亚族13 个属似可划分为6 个自然属群。     

江浙獐牙菜的小孢子发生和雄配子体形成及其系统学意义

采用常规石蜡切片技术,对江浙獐牙菜(Swertia hickinii Burk)花药壁形成、小孢子发生和雄配子体形成过程进行了研究。结果表明:(1)花药四室,花药壁由表皮、药室内壁、中层和绒毡层组成,药壁发育为双子叶型。绒毡层异型起源,腺质型。花粉成熟时药室内壁径向加长并纤维状加厚,表皮宿存。(2)小孢子母细胞在减数分裂过程中胞质分裂为同时型;小孢子四分体排列方式主要为四面体型,也有左右对称型和"T"型等其他类型;成熟花粉为3-细胞型,具三萌发沟。另外,对獐牙菜属的雄性胚胎学特征进行了全面总结,并与龙胆属、蔓龙胆属及双蝴蝶属进行比较归纳出其共性。研究认为,花药表皮宿存或退化,是獐牙菜属与双蝴蝶属的重要区别之一。     

扁桃花药开裂前后壁层细胞形态变化及分析

为探明扁桃花药开裂前后壁层细胞形态变化,以鹰咀扁桃鳞片开裂期、小蕾期、大蕾期和盛花期的花蕾为研究材料,运用石蜡切片法结合铁苏木精染色法、考马斯亮蓝染色法、PAS染色法对花药壁层细胞进行染色;同时用Nikon SMZ-250体视显微镜拍摄花药开裂过程,观测花粉粒长、短轴长度。结果表明:(1)从鳞片开裂期到小蕾期,花粉粒的长、短轴长度都增大,多糖颗粒数量增多,绒毡层细胞完全消失,中层细胞和药隔处细胞逐渐溶解;药室内壁细胞切向长度增加幅度大于径向长度,内、外壁长度都增大,螺旋状纤维进一步形成;表皮细胞切向长度增加幅度大于径向长度。(2)从小蕾期到大蕾期花粉粒长、短轴长度明显增大,多糖颗粒持续增多;中层细胞和药隔处细胞大部分溶解;药室内壁细胞径向、切向长度持续增大,内壁长度增大、外壁长度趋于稳定,多糖颗粒数量减少,螺旋状纤维基本形成;表皮细胞切向减小幅度大于径向。(3)从大蕾期到花药半开裂,花粉粒长、短轴长度稍微增大;中层细胞和药隔处细胞完全溶解;药室内壁细胞切向长度持续增大,径向长度趋于稳定,内壁长度持续增大,外壁长度逐渐减小,多糖颗粒数量较少;表皮细胞切向、径向长度持续减小。(4)花药半开裂后,花粉粒长、短轴长度都减小;药室内壁细胞和表皮细胞切向、径向长度都减小;药室内壁细胞内、外壁长度减小并趋于接近,内壁长度减小趋势出现晚于外壁。研究认为,扁桃花药壁层细胞形态变化是花药开裂的基础,并与花药开裂密切相关。     

蒙古莸小孢子发生和雄配子体发育的研究

运用常规石蜡切片技术对蒙古莸小孢子发生和雄配子体发育进行了观察.结果表明:(1)花药4室,花药壁由4层细胞组成,由外向内分别为表皮、药室内壁、1层中层和绒毡层,花药壁发育方式为双子叶型.(2)花药壁表皮具多细胞腺体,药室内壁、药隔部分细胞发育后期均发生纤维性加厚.(3)绒毡层细胞有两种来源,外周部分来源于初生壁细胞,近药隔部分来源于药隔细胞.腺质绒毡层,发育后期为二核.(4)小孢子母细胞减数分裂过程胞质分裂为同时型,四分体多数为四面体型,偶有左右对称型.(5)成熟花粉为2细胞型,具3个萌发沟.     

A floral third whorl-specific marker gene in the dioecious species white campion is differentially expressed in mutants defective in stamen development

The CCLS4 gene of white campion is specifically expressed in anther epidermis and endothecium from pre- to post-meiotic stages. We report on a detailed in situ analysis of the gene's expression and show that it is a marker of the floral third whorl. The gene is expressed (1) in the anther (epidermis, parietal cells and the derived endothecium) in normally developing stamens and (2) in distinct sub-domains of third-whorl epidermis in mutants exhibiting aberrant states of parietal differentiation. Our results suggest that CCLS4 may fulfil different functions during pre- and post-meiotic anther development and reveal the complex role parietal cells may play during early stamen formation.     

大百合小孢子发生和雄配子体发育研究

用常规石蜡切片技术和压片法对大百合小孢子发生和雄配子体发育进行观察。结果表明：花药4室,花药壁由表皮、药室内壁、中层和腺质绒毡层组成,花药壁发育方式为单子叶型,药室内壁部分细胞发育后期发生纤维状加厚。小孢子母细胞减数分裂过程的胞质分裂为连续型,四分体多数为左右对称型,偶有四面体型。成熟花粉为2细胞型,具1个萌发沟。经TTC法检验,成熟花粉生活力为86.3%。从小孢子的发生及雄配子体发育的整个过程看,未见异常现象,能形成大量正常的成熟花粉。     

Elucidating the mechanism of poricidal anther dehiscence in Miconia species (Melastomataceae)

Melastomataceae have porate anthers. However, unlike Solanaceae and many monocots, in which the poricidal dehiscence depends on the presence of a mechanical layer (often the endothecium), most members of Melastomataceae have no evident specialized layer related to the poricidal opening. The goal of this study was to characterize the tissues that form the apical pore of the anther in 10 Miconia species, which may help to understand the nearly unknown mechanism of anther dehiscence in this genus, considered to be one of the largest and most diverse New World genera. Before anthesis, the apical pores of all of the species are closed by a uniseriate epidermis, the cells of which lack a cuticle. In contrast, the epidermis of the remainder of the anther is covered by a thick, ornamented cuticle. Among Myrtales, the Melastomataceae form a clade with Alzateaceae, Crypteroniaceae and Penaeaceae, almost all of which have anthers with endothecium lacking wall thickenings. In these families, the endothecium may or may not be present in the mature anther, with degenerating cells in the latter case. Anther dehiscence does not depend on the endothecium as the mechanical layer, and this process is still not well understood. However, in the Miconia species studied here, the cuticle may prevent tissue dehydration, and the pore opening seems to be due to the passive process of dehydration taking place only in the pore region due to the absence of the cuticle.     

The systematic significance of the endothecium in Begoniaceae

The endothecial thickening patterns in 173 species, representing the three genera of Begoniaceae, were investigated using cleared macerated anthers. Begoniaceae contain taxa with U-shaped thickenings, perforate base plates, entire base plates, tympanate base plates, anticlinal bars, and taxa that lack endothecial thickenings. The degree of correlation between these endothecial classes and accepted taxonomic boundaries varies: some classes are confined to a single taxonomic unit (e.g. absence of thickenings, non-perforate tympanate base plates) while others are present in several taxonomic units (e.g. U-shapes, perforate base plates). This study provides an improved understanding of the diversity of endothecial patterns in a large genus and indicates that in the Begoniaceae the endothecium is of moderate systematic value within and between closely related sections in Begonia and in Symbegonia . We conclude that the endothecium exhibits high levels of homoplasy between distantly related sections of Begonia . In addition, we show that in contrast to past observations of the endothecium in dicotyledons, apical anther dehiscence in the Begoniaceae is not correlated with a loss of endothecial thickening.     

毛钩藤的小孢子发生和雄配子体发育

在光学显微镜和透射电镜下观察了毛钩藤(Uncaria hirsuta Havil.)的小孢子发生和雄配子体发育过程.结果表明,毛钩藤花两性,具5枚雄蕊,花药4室,花药壁由表皮、药室内壁、中层和绒毡层组成,花药开裂时,药室内壁高度纤维化带状加厚.花药壁的发育方式属于双子叶型,小孢子母细胞减数分裂的胞质分裂为同时型.小孢子在四分体时期开始沉积花粉外壁,小孢子大液泡化时期开始沉积花粉内壁.成熟花粉为2-细胞型.毛钩藤的花粉发育特征和茜草科植物基本一致.毛钩藤绒毡层属于分泌型,双重起源,分别起源于次生周缘层和药隔细胞.小孢子发育早期绒毡层开始降解并分泌形成大量乌氏体,花药开裂时绒毡层完全消失,剩下少量乌氏体.小孢子早期内壁加厚突出形成,小孢子细胞核分裂以后内壁加厚开始脱落,花药开裂时,只剩下少量的内壁加厚突出.初步推测,内壁加厚突出与乌氏体共同作用为雄配子体的发育提供营养物质.     

Characterization and genetic mapping of a mutation (ms35) which prevents anther dehiscence in Arabidopsis thaliana by affecting secondary wall thickening in the endothecium

The male sterile mutant, ms35 , of Arabidopsis thaliana was produced by X-irradiation of seeds. The mutant produces fertile pollen, but is male sterile because the anthers do not dehisce. Anther development in ms35 plants occurs as in wild-type Arabidopsis until shortly after microspores are released from meiotic tetrads. Thereafter, in the wild type, bands of lignified, cellulosic secondary wall thickenings are laid down around the cells of the anther endothecium. In contrast, wall thickenings are not formed in the endothecium of the ms35 mutant. Development of other lignified tissues, for example the vascular tissue of the stamen, occurs normally in ms35 plants. In mutant anthers, as pollen maturation is completed, the stomium is cleaved but the anther wall does not retract to release pollen. The block in anther dehiscence in ms35 plants is specifically correlated with the absence of endothecial wall thickenings. The ms35 mutation represents the first genetic evidence in support of the proposed role of the endothecium in anther dehiscence. The ms35 gene was mapped to the top arm of chromosome 3 ( hy2 -(4.17±2.31 cM)- ms35 -(32.14±5.45 cM)- gl1 ).     

Anther wall and pollen development in Ophrys mammosa L. (Orchidaceae)

The objective of this study was to investigate anther wall and pollen development in Ophrys mammosa. Primary sporogen tissue resembles longitudinal cells with divided archeosporal cells. Thereafter these primary sporogen tissue cells re-divide anticlinally and periclinally forming secondary sporogen tissue. Microsporogenesis was successive type. Microgametogenesis occurred at the distal poles of the microspores. In addition, dense starch accumulation was detected in the pollen. Pollinia and massulae are separated from each other by dead cells filled with callose, according to histochemical preparations. The anther wall was a four-layered “monocotyledon” type. There was ring-like wall thickening in the endothecium. The tapetum is of the glandular type. When these two developmental processes are compared, it is seen that the anther wall has become mature by the sporogen tissue phase and is composed of only epidermis and endothecium at the beginning of microgametogenesis.     

葱兰大小孢子发生和雌雄配子体发育及其系统学意义

采用常规石蜡切片技术,对石蒜科葱兰的花药壁发育、大小孢子的发生和雌雄配子体的发生过程进行了研究,并对葱兰属、石蒜科、百合科以及葱科的胚胎学特征进行比较讨论。结果表明:(1)葱兰花药四室,药壁由表皮、药室内壁、中层和绒毡层组成;药壁发育类型为单子叶型,绒毡层的类型为分泌型;花粉成熟时药室内壁径向加长并纤维状加厚,表皮宿存;小孢子母细胞在减数分裂过程中胞质分裂为连续型,小孢子四分体排列方式主要为四面体型,还有少数一些为左右对称型,成熟花粉为2-细胞型。(2)葱兰的雌蕊3心皮合生,子房下位,中轴胎座,3室,每室具2列倒生胚珠;胚珠双珠被,厚珠心,具蓼型胚囊。(3)葱兰属的胚胎学特征与石蒜科的其他种类存在较大的差异,如葱兰属花药壁发育为单子叶型,而石蒜科花药壁发育主要为双子叶型,但葱兰属的这些胚胎学特征却和百合科较为相似。     

杉木小孢子叶球发育过程中形态结构变化

以扬州地区生长的成年杉木为实验材料,通过采用数码相机拍摄、体视镜、扫描电镜以及半薄切片等方法,对杉木小孢子叶球发育、小孢子囊发育及其散粉规律进行详细观察。结果发现,10月中旬,杉木小孢子叶球形成并着生于新枝顶端。翌年3月中下旬,小孢子叶球成熟,进入散粉期,散粉首先从小孢子叶球基部开始依次向上部扩散。小孢子叶在孢子叶球主轴上螺旋排列,单个小孢子叶通常由3个小孢子囊组成,构成三角形。小孢子囊壁由1层表皮细胞、1~2层中间层细胞和1层绒毡层细胞组成,表皮细胞首先形成,并向内分化出2~3层细胞,分别分化形成中层和绒毡层,最后中层和绒毡层消失。杉木的小孢子囊通过开裂口控制其开裂,20℃室温下整个小孢子叶球散粉时间持续约18 h,单个小孢子叶的散粉时间为8~10 h。以上结果显示,杉木小孢子叶球的发育过程经历了体积增大、鳞片开张及散粉等阶段,这些形态和结构上的变化利于提高散粉效率,这说明杉木在长期的演化过程中,形成了许多有利于风媒传粉的结构特征。     

紫斑牡丹的花药发育和小孢子发生

紫斑牡丹的花药是在花芽发育的第３个年周期中,从雄蕊原厚基发育而来,花药壁按特有方式发生,主要特点是绒毡层与次生造孢细胞同源。花药由４个花粉囊组成,绒毡层属分泌型,中层３－４层,其中１－３层与药室内壁同步发育出纤维素壁加厚,并在花药成熟时宿存。小包子母细胞减数分裂同时开始,但不同时结束,分裂过程高度不同步。胞质分裂为同时型,四分体中小孢子排列呈正四面体形,减数分裂前期Ⅰ通常有Ｂ－染色体和染色体桥形。     

甜菊花药壁的超微结构及功能研究

1.甜菊花药发育至四分体时期,绒毡层细胞达最大程度的发育。细胞器丰富且呈活跃状态,脂肪微粒沿内切向面和径向面沉积。2.绒毡层周原质团具有大量呈现活跃功能的细胞器,并不断积累各种物质,其RNA和蛋白质合成能力亦较强,认为周原质团有一定的重组行为。3.发育早期药室内壁细胞结构较简单,但至周原质团物质将被小孢子完全吸收时,其内质网和高尔基体剧增,RNA和蛋白质合成能力亦骤然增强,认为此时药室内壁细胞对花粉发育起供养作用。     

湖北双蝴蝶小孢子发生及雄配子体发育(英文)

首次报道了湖北双蝴蝶小孢子发生和雄配子体发育。主要结果如下:花药四室;药壁发育为双子叶型;绒毡层异型起源,属腺质型绒毡层,药隔处的绒毡层细胞形成类胎座,其余部位的绒毡层细胞仍为一层细胞;花药成熟时,药室内壁纤维状加厚且柱状伸长,表皮细胞减缩退化,纤维状加厚不明显。小孢子母细胞减数分裂为同时型,四分体排列方式主要为四面体形,少数为十字交叉形;成熟花粉多为2-细胞型,偶见3-细胞型,具三萌发孔。     

獐牙菜小孢子发生及雄配子体发育(英文)

用石蜡切片法对獐牙菜小孢子发生及雄配子体发育过程进行首次观察研究。主要结果如下:花药四室,药壁发育为基本型;绒毡层异型起源,属于腺质型绒毡层,药室内具有的退化绒毡层核是早期该层细胞有丝分裂凸入药室中央并原位退化形成的;中层细胞2层;药室内壁同表皮同时宿存,细胞柱状伸长,纤维状加厚。小孢子母细胞减数分裂为同时型,四分体排列方式主要为四面体形,少数为左右对称形和十字交叉形;成熟花粉多为2-细胞类型,偶见3-细胞型,具三萌发孔。     

Glyphosate-induced anther indehiscence in cotton is partially temperature dependent and involves cytoskeleton and secondary wall modifications and auxin accumulation

Yield reduction caused by late application of glyphosate to glyphosate-resistant cotton (Gossypium hirsutum; GRC) expressing CP4 5-enol-pyruvylshikmate-3-P synthase under the cauliflower mosaic virus-35S promoter has been attributed to male sterility. This study was aimed to elucidate the factors and mechanisms involved in this phenomenon. Western and tissue-print blots demonstrated a reduced expression of the transgene in anthers of GRC compared to ovules of the same plants. Glyphosate application to GRC grown at a high temperature regime after the initiation of flower buds caused a complete loss of pollen viability and inhibition of anther dehiscence, while at a moderate temperature regime only 50% of the pollen grains were disrupted and anther dehiscence was normal. Glyphosate-damaged anthers exhibited a change in the deposition of the secondary cell wall thickenings (SWT) in the endothecium cells, from the normal longitudinal orientation to a transverse orientation, and hindered septum disintegration. These changes occurred only at the high temperature regime. The reorientation of SWT in GRC was accompanied by a similar change in microtubule orientation. A similar reorientation of microtubules was also observed in Arabidopsis (Arabidopsis thaliana) seedlings expressing green fluorescent protein tubulin (tubulin alpha 6) following glyphosate treatment. Glyphosate treatment induced the accumulation of high levels of indole-3-acetic acid in GRC anthers. Cotton plants treated with 2,4-dichlorophenoxyacetic acid had male sterile flowers, with SWT abnormalities in the endothecium layer similar to those observed in glyphosate-treated plants. Our data demonstrate that glyphosate inhibits anther dehiscence by inducing changes in the microtubule and cell wall organization in the endothecium cells, which are mediated by auxin.     

芒果花药发育的细胞化学研究

芒果花药发育中,花药药壁体细胞中淀粉粒多糖和脂滴类物质一直很少,仅药室内壁细胞中有零星淀粉粒分布.到二胞花粉早期,花粉营养细胞中的大液泡消失,开始积累淀粉粒.芒果成熟花粉中储存营养物质主要是淀粉粒,而脂类物质一直很少.