日本蹄盖蕨配子体发育的研究

采用混和土培养日本蹄盖蕨(Athyrium niponicum)孢子,显微镜下观察记录其孢子萌发及配子体发育过程。结果表明:孢子黑褐色,赤道面豆形,极面观椭圆形,单裂缝。播种7 d左右孢子萌发,萌发类型为向心型,配子体发育为铁线蕨型。丝状体7~11细胞时开始发育为片状体。播种14 d后发育形成幼原叶体,成熟原叶体呈心脏形。原叶体边缘可产生单细胞毛状体。播种后20 d左右精子器出现,精子器近圆球形,由3细胞组成。7 d后颈卵器出现,成熟颈卵器3~5层细胞高。精卵受精后14 d左右即可观察到从原叶体上生成的幼胚。     

同形鳞毛蕨成精子囊素系统的初步研究

研究了同形鳞毛蕨成精子囊素对该种和水蕨孢子萌发和配子体发育的影响,结果表明：同形鳞毛蕨配子体能产生成精子囊素,该成精子囊素能抑制同种孢子的萌发,抑制作用随配子体成熟度的增加而增强;同形鳞毛蕨成精子囊素还可促进同种孢子发育为雄配子体;光照条件下,同形鳞毛蕨成精子囊素对水蕨孢子萌发和配子体发育影响不大,黑暗条件下,同形鳞毛蕨成精子囊素能显著的促使水蕨孢子提早萌发,但都不影响其孢子最终萌发率和配子体的性别分化,表明同形鳞毛蕨和水蕨的成精子囊素不属于同一系统。     

狭眼凤尾蕨配子体发育及其成精子囊素对水蕨配子体发育的影响

对狭眼凤尾蕨（Pteris biaurita）配子体发育特征及其外源成精子囊素对模式植物水蕨（Ceratopteris thalictroides）在黑暗和光照条件下孢子萌发和配子体发育的影响进行了研究。结果表明：（1）狭眼凤尾蕨孢子深褐色,三裂缝,孢子萌发为书带蕨型,原叶体发育为水蕨型,无毛状体产生;培养发现,其配子体能产生精子器,但不产生颈卵器,当接种密度适中时,可进行无配子生殖。（2）在光照和黑暗条件下狭眼凤尾蕨成精子囊素有促进和抑制水蕨孢子萌发的作用,但效果均不显著。（3）在光照条件下,狭眼凤尾蕨成精子囊素可以延迟水蕨心脏形配子体分生组织缺刻的形成,但对其配子体形态和性别分化无明显影响;而在黑暗条件下狭眼凤尾蕨成精囊素对水蕨长条形配子体的形态发育具有一定影响,与对照组相比其顶端分生组织发达,整体呈长楔形,对性别分化影响不显著。可见,狭眼凤尾蕨和水蕨不具有同种成精子囊素系统。     

广西蕨类植物孢子形态的研究Ⅰ.水龙骨科

该文是广西蕨类植物孢子形态研究的第一部分。首次利用光学显微镜和扫描电子显微镜对广西产水龙骨科6属9种植物的孢子形态进行了观察研究。对每个种的孢子形态特征及表面纹饰进行了描述。水龙骨科6属9种植物孢子都为单裂缝类型孢子,孢子外壁表面具有皱状、细孔状、蠕虫状、瘤状、光滑、索状条纹和颗粒状纹饰7种纹饰类型。讨论了各属、种问的差异,为水龙骨科系统分类及孢粉学研究提供资料。     

阔鳞瘤蕨(水龙骨科)配子体形态发育的研究

利用光学显微镜详细观察记录了阔鳞瘤蕨孢子萌发、配子体发育及幼孢子体形成的整个形态发育过程。结果表明:成熟孢子黄色,极面观椭圆形,赤道面观肾形,近极单裂缝,表面具大小不一的球形颗粒。接种后6~8 d孢子萌发,萌发类型为书带蕨型,形成3~7个细胞的丝状体。原叶体发育为槲蕨型,接种后30 d左右进入片状体阶段,毛状体出现在片状体形成之后,幼原叶体短舌状,成熟原叶体心脏形。精子器在接种后60 d左右开始产生,颈卵器在精子器发生后10 d左右形成,每个原叶体上只能形成一个受精卵。培养基培养的片状体常在基部进行营养繁殖。     

Possible involvement of Ca<Superscript>2+</Superscript>-dependent protein kinases in spore germination of the fern<Emphasis Type="Italic">Osmunda Japonica</Emphasis>

Fern gametophyte is a good model system to investigate signal transduction in plant cells. In this work, we examined whether CDPKs are involved in the mechanisms of spore germination of the fernOsmunda japonica. A protein extract from the spores included four CDPK isoforms with relative molecular weights of 56, 53, 49, and 47 kDa, as detected by immunoblot analysis, and they showed CDPK-like activities, as detected by in-gel protein-kinase assay. It was also found that the inhibitors effective on CDPKs, such as a general protein kinase inhibitor, K252a, and a calmodulin antagonist, W-7, largely suppressed the spore germination, and that many proteins of the spores were phosphorylated in vivo in a calcium dependent manner in the period when the spores require external Ca²⁺ for the germination. Furthermore, we showed that Sr²⁺ and Mn²⁺, which could substitute for Ca²⁺ in the spore germination, were also able to activate theOsmunda CDPKs. From these results, we concluded that CDPKs would participate in the spore germination ofO. japonica.     

Jasmonic acid promotes division of fern protoplasts, elongation of rhizoids and early development of gametophytes

The effects of jasmonic acid (JA) on spore germination, early gametophyte development and sporophytic protoplast culture of the fern Platycerium bifurcalum (Cav.) C. Chr. were investigated. JA and no influence on spore germination and primary rhizoid initiation, but significantly promoted early gametophyte development, which was evident from the longer primary rhizoids as well as the higher number of rhizoids and cells per gametophyte. Jasmonic acid (1 μ M ) also promoted the transition of gametophytes from a filamentous to a planar growth. Optimal primary rhizoid elongation and highest cell division activities in the gametophytes were observed at 0.01–1 μ M JA, while the highest number of rhizoids on gametophytes was obtained at 0.1–1 μ M JA. Jasmonic acid (0.01 μ M ) also stimulated initial protoplast divisions. Except for the experiment in which the effect of JA on germination was tested. JA concentrations exceeding 1 μ M did not promote cell elongation or cell division but were instead inhibitory. On the basis of these findings, we propose that JA may be involved in early stages of P. bifurcatum development.     

中国瓦韦属三种植物的细胞分类学研究

首次报道中国分布的3种瓦韦属植物的染色体数目,分别为线叶瓦韦,2n=42;丽江瓦韦,2n=144;西藏瓦韦,2n=50。其中,线叶瓦韦n=21是水龙骨科一个新的染色体基数。结合已有资料对染色体数目在瓦韦属中的重要分类学价值进行了讨论。     

蕨类植物孢子与种子植物花粉萌发的比较

蕨类植物孢子与种子植物花粉在有性生殖过程中都具有重要的作用。花粉作为种子植物的雄配子体,通过萌发后极性生长的花粉管将精细胞送到胚囊完成受精作用。蕨类植物孢子作为配子体的原始细胞,通过不对称的有丝分裂产生一大一小两个细胞,小细胞萌发出极性生长的假根,大细胞继续分裂发育为原叶体（配子体）。成熟的花粉和蕨类植物孢子都是代谢高度静止的细胞,两者的萌发过程不仅都受到各种不同环境因子的影响,而且在信号转导、极性建立和能量代谢等方面可能有着相似的调控机制。本文综述了蕨类植物孢子和种子植物花粉萌发过程的差异和保守性特征。     

A cytotaxonomic study of 10 species of the Polypodiaceae from Yunnan,China

A cytotaxonomic study was made of 10 fern species belonging to 7 genera of Polypodiaceae from Yunnan, China. Seven new records (including one cytotype) were reported in this paper. The putative reproduc-tive manners were inferred from cytological characters and spore counting. The chromosome numbers were 2n=70 in Polypodiastrum mengtzeense, Lepisorus bicolor; 2n=72 in Polypodiode amoena, P. wattii, L. mac-rosphaerus, Lepidogrammitis rostrata, Drymotaenium miyoshianum, Tricholepidium maculosum, Phymatopteris oxyloba; and 2n=108 in P. trisecta. The reproductive type in P. trisecta is triploid apogamous while it is of the sexual diploid reproductive type in the other species of the genus Phymatopteris. Based on our study and previous data, the significance of chromosome number in phylogenetic study was discussed.     

水龙骨科植物的引种及种质资源保存

通过对５０种水龙骨科（Ｐｏｌｙｐｏｄｉａｃｅａｅ）植物的引种栽培,研究了水龙骨科植物的引种方法、栽培管理措施和繁殖技术,初步应用离体保存技术保存了１０种水龙骨科植物,并对主要类群做了应用及观赏性状评价。     

球腺肿足蕨的配子体发育特征及其系统学意义

采用改良Knop’s营养液液体和固体培养基,对球腺肿足蕨的孢子进行人工培养,利用光学显微镜观察其孢子的萌发及配子体发育过程。结果表明:成熟的孢子深褐色,不透明,极面观为椭圆形,赤道面观为豆形,单裂缝,周壁具密集的波纹状褶皱。孢子萌发类型为书带蕨型,原叶体发育类型为三叉蕨型。孢子接种后7d左右萌发,30d左右形成为片状体,50d左右发育为幼原叶体,幼原叶体不对称,但成熟原叶体心脏形对称。原叶体边缘及背腹面都具乳头状毛状体。75d左右精子器出现,精子器近圆球形,由3个细胞构成。90d左右颈卵器出现,成熟颈卵器颈部由4～5列细胞构成,3～5层细胞高。原叶体受精后1个月内可看到幼孢子体生成。最后讨论其系统学意义。     

四回毛枝蕨配子体发育的研究

采用MS培养基培养四回毛枝蕨孢子,利用光学显微镜详细观察记录了其孢子萌发、配子体发育及幼孢子体形成的整个过程。结果表明:成熟的孢子黑褐色,不透明,极面观圆球形,赤道面观蚕豆型,单裂缝,表面微褶皱。播种后8d左右萌发,萌发类型为书带蕨型,配子体发育为三叉蕨型。播种20d左右发育为片状体。播种30d左右形成幼原叶体,幼原叶体暂不对称,成熟原叶体呈蝴蝶形。原叶体边缘及背腹面都具毛状体,数量丰富,单细胞。播种50d左右开始有性器官出现,精子器近圆球形,由3细胞构成,成熟颈卵器颈部由5列细胞构成。原叶体受精后1月内可看到幼胚生成。     

龙津蕨的配子体发育特征及其系统学意义

采用改良Knop's营养液液体培养基于25℃恒温培养箱中培养龙津蕨(Mesopteris tonkinensis)的孢子,每天光照12 h,黑暗12 h,光照强度为2 500 lx。用光学显微镜观察记录其孢子萌发、配子体发育的全过程,为龙津蕨系统学的研究提供配子体发育方面的详实资料。结果表明:成熟孢子深褐色,不透明,两侧对称,极面观椭圆形,赤道面观圆角三角形,具单裂缝,孢子周壁具密集的脊状褶皱。播种后15 d左右萌发,形成2~5个细胞长的丝状体。孢子萌发类型为书带蕨型(vittaria-type)。具单细胞假根,不含叶绿体,基部膨大。20 d左右发育成片状体,30 d左右形成幼原叶体,幼原叶体不对称,成熟原叶体心脏形对称,56 d左右形成成熟原叶体,原叶体发育类型为铁线蕨型(adiantum-type)。幼原叶体仅左右两翼顶端细胞产生乳突毛状体,成熟原叶体边缘及背腹面都具少量乳突毛状体,毛状体由单细胞构成。68 d左右精子器开始出现,精子器近圆球形,由基细胞、环细胞、盖细胞构成。75 d左右颈卵器出现,成熟颈卵器颈部由3层细胞构成。其侧面观柱状,顶面观为铜面状。颈卵器垂直于原叶体表或向原叶体基部倾斜。另外,根据已知的金星蕨科其他属的配子体发育特征,发现龙津蕨配子体发育的这些特征与他们存在较大的区别,因此龙津蕨系统学位置还有待于进一步研究。     

Analysis of the action of compounds that inhibit the germination of spores of Bacillus species

AIMS: To determine the mechanism of action of inhibitors of the germination of spores of Bacillus species, and where these inhibitors act in the germination process. METHODS AND RESULTS: Spores of various Bacillus species are significant agents of food spoilage and food-borne disease, and inhibition of spore germination is a potential means of reducing such problems. Germination of the following spores was studied: (i) wild-type B. subtilis spores; (ii) B. subtilis spores with a nutrient receptor variant allowing recognition of a novel germinant; (iii) B. subtilis spores with elevated levels of either the variant nutrient receptor or its wild-type allele; (iv) B. subtilis spores lacking all nutrient receptors and (v) wild-type B. megaterium spores. Spores were germinated with a variety of nutrient germinants, Ca2+-dipicolinic acid (DPA) and dodecylamine for B. subtilis spores, and KBr for B. megaterium spores. Compounds tested as inhibitors of germination included alkyl alcohols, a phenol derivative, a fatty acid, ion channel blockers, enzyme inhibitors and several other compounds. Assays used to assess rates of spore germination monitored: (i) the fall in optical density at 600 nm of spore suspensions; (ii) the release of the dormant spore's large depot of DPA; (iii) hydrolysis of the dormant spore's peptidoglycan cortex and (iv) generation of CFU from spores that lacked all nutrient receptors. The results with B. subtilis spores allowed the assignment of inhibitory compounds into two general groups: (i) those that inhibited the action of, or response to, one nutrient receptor and (ii) those that blocked the action of, or response to, several or all of the nutrient receptors. Some of the compounds in groups 1 and 2 also blocked action of at least one cortex lytic enzyme, however, this does not appear to be the primary site of their action in inhibiting spore germination. The inhibitors had rather different effects on germination of B. subtilis spores with nutrients or non-nutrients, consistent with previous work indicating that germination of B. subtilis spores by non-nutrients does not involve the spore's nutrient receptors. In particular, none of the compounds tested inhibited spore germination with dodecylamine, and only three compounds inhibited Ca2+-DPA germination. In contrast, all compounds had very similar effects on the germination of B. megaterium spores with either glucose or KBr. The effects of the inhibitors tested on spores of both Bacillus species were largely reversible. CONCLUSIONS: This work indicates that inhibitors of B. subtilis spore germination fall into two classes: (i) compounds (most alkyl alcohols, N-ethylmaleimide, nifedipine, phenols, potassium sorbate) that inhibit the action of, or response to, primarily one nutrient receptor and (ii) compounds [amiloride, HgCl2, octanoic acid, octanol, phenylmethylsulphonylfluoride (PMSF), quinine, tetracaine, tosyl-l-arginine methyl ester, trifluoperazine] that inhibit the action of, or response to, several nutrient receptors. Action of these inhibitors, is reversible. The similar effects of inhibitors on B. megaterium spore germination by glucose or KBr indicate that inorganic salts likely trigger germination by activating one or more nutrient receptors. The lack of effect of all inhibitors on dodecylamine germination suggests that this compound stimulates germination by creating channels in the spore's inner membrane allowing DPA release. SIGNIFICANCE AND IMPACT OF THE STUDY: This work provides new insight into the steps in spore germination that are inhibited by various chemicals, and the mechanism of action of these inhibitors. The work also provides new insights into the process of spore germination itself.     

亮毛蕨的配子体发育特征及其系统学意义

采用原生境土培养方法对亮毛蕨(Acystopteris japonica)进行培养,并对其配子体发育过程进行了观察。结果表明:亮毛蕨植物的孢子二面体型,极面观为椭圆形,赤道面观肾形,单裂缝,无周壁,外壁具棒状纹饰,孢子萌发为书带蕨型(Vittaria-type),原叶体发育为铁线蕨型(Adiantum-type)。丝状体4～7个细胞,片状体小楔状,仅3～5个细胞宽,成熟原叶体心形,裸露,初生假根具叶绿体,颈卵器较短;配子体发育较迅速,假根具分枝和膨大,精子器囊由3个壁细胞构成,颈卵器略弯曲。本研究首次观察到亮毛蕨的颈卵器壁细胞内含有球形颗粒,但其功能不详。亮毛蕨的配子体发育过程兼有原始和进化的特点。在适宜的光照和温度下,土壤培养亮毛蕨原叶体的成苗率达95%以上,移栽成活率达89%以上。     

隐子蕨属（水龙骨科）植物在中国的首次承认

首次承认水龙骨科（Polypodiaceae）隐子蕨属（Crypsinus）植物在中国的分布。文中列出了该属与假瘤蕨属（Phymatopteris）和修蕨属（Selliguea）的区别特征,给出隐子蕨属植物在中国的唯一一种——三指隐子蕨（Crypsinus trilobus）的文献引证,特征描述并附图。