Spore Germination and Gametophyte Development in Three Species of Asplenium

Laboratory and field experiments involving Asplenium ruta-murariaL., Asplenium trichomanes L. subsp. quadrivalens D.E. Meyeremend. Lovis and Asplenium scolopendrium L. [= Phyllitis scolopendrium(L.) Newm.] revealed differences in their temperature requirementsfor germination and in their sexual development on soil. Thegermination responses of A. trichomanes and A. scolopendriumto culture temperatures of 10, 15, 20 and 25 °C were verysimilar and all spores were able to germinate at 10 °C.Spores of A. ruta-muraria differed in that germination was slowerat 15-25 °C and very much delayed, or even inhibited, at10 °C. Both laboratory and field cultures of A. trichomanesand A. scolopendrium produced male, female and bisexual gametophyteswhereas those of A. ruta-muraria produced only males and bisexuals.The ecological significance of these differences is discussed.Copyright1994, 1999 Academic Press Fern, Asplenium ruta-muraria, Asplenium trichomanes, Asplenium scolopendrium, Phyllitis scolopendrium, spore germination, gametophyte, reproductive biology, temperature effects, field experiments     

The Effect of Gabaculine on Germination and Gametophyte Morphogenesis of Anemia phyllitidis L.Sw.

Gabaculine, applied to germinating spores of the fern Anemiaphyllitidis in concentrations between 10^–4 M and 10^–6M inhibits chlorophyll synthesis together with considerablesimplification of chloroplast ultrastructure. Though gabaculinereduced phytochrome-induced morphogenetic effects (cell shape,inhibition of hormonal antheridium induction), the rate of redlight-induced spore germination, however, has not been affectedby the inhibitor. This indicates significant differences betweenthe two types of photomorphogenetic reactions regarding theirdependency on phytochrome homeostasis. (Received April 21, 1986; Accepted October 22, 1986)     

Mechanism and Factors Influencing the Veronal Inhibition of Bacterial Spore Germination

The inhibitory effect of sodium 5,5-diethyl barbiturate (Veronal) on the L-alanine-induced initiation of germination of Bacillus subtilis spores was examined. Veronal reversibly inhibited the initiation of germination by a noncompetitive mechanism. The inhibition was time-independent and it took place whether L-alanine was or was not allowed to permeate the spore before the addition of the inhibitor. The concentration of the inhibitor and the pH of the initiation system were important factors determining the effectiveness of Veronal as an inhibitor. The magnitude of the inhibition increased linearly with decreasing pH at constant concentration and with increasing concentration at constant pH. These results suggest that the inhibition involves a permeability phenomenon related to the access of drug to the active sites in the spore and that the entry of Veronal into the spores is regulated by the concentration of undissociated molecule. At the physiologically important pH of 7.4, initiation with alanine in phosphate buffer at high spore densities (about 10(9) spores per ml) was 50% inhibited by 4 mM Veronal, and 8mM Veronal inhibited initiation completely. L-Alanine initiation in tris(hydroxymethyl)amino-methane-hydrochloride buffer was completely inhibited by 5 mM Veronal. The inhibition could be partially reversed by the combined addition of D-fructose, D-glucose, and K(+). Possible reasons for the failure of otherwise inhibitory concentrations of Veronal to inhibit completely the L-alanine-induced initiation when a combination of fructose, glucose, and K(+) was present and a suggested relationship to two functional roles of L-alanine in the initiation of germination are discussed.     

重金属铅对3种蕨类植物孢子萌发和配子体发育的影响

研究了重金属铅对水蕨、中华桫椤和扇蕨孢子萌发及其对水蕨配子体发育的影响。结果表明：随着铅浓度的增加,水蕨、中华桫椤和扇蕨孢子的萌发率逐渐降低;在低于10^-4 mol·L^-1的环境中,水蕨孢子可以正常萌发;在低于10^-5 mol·L^-1的环境中,中华桫椤和扇蕨孢子能正常萌发;水蕨、中华桫椤和扇蕨的孢子都对铅具有一定的耐受性;铅对水蕨配子体的发育存在一定影响,铅使水蕨配子体呈不规则的心脏形,多发育为雄配子体;精子器凹陷入原叶体边缘;配子体细胞中叶绿体分布不均匀。本研究为铅污染土壤的植物修复筛选后备植物。     

Aphidicolin Inhibition of DNA Synthesis and Germination in Spores of Anemia phyllitidis L. Sw

Aphidicolin inhibits DNA synthesis and nuclear division in spores of Anemia phyllitidis. In spite of blocked DNA replication, spores germinate under continuous dark conditions, if induced by addition of 5 × 10⁻⁵ grams per milliliter gibberellic acid. Differentiation of aphidicolin-treated prothallia indicate the existence of a prepattern in the dry spore which is realized independent of cell division during early events of spore germination.     

Partial characterization of an antheridiogen of Anemia mexicana: Comparison with the antheridiogen of A. phyllitidis

An antheridiogen of Anemia mexicana Klotzsch has been partially characterized by combined gas chromatography-mass spectrometry and gas chromatography-Fourier transform/infra-red spectrometry. It is a C₁₉-gibberellin(GA)-like compound with one carboxyl group, an exocyclic methylene group and a lactone ring. It also has one hydroxyl-group and one double-bond equivalent which has not been determined. On the basis of its mass spectrum, it is not identical to previously identified monohydroxy GAs with one ring double bond such as GA₅, GA₇, GA₃₁ and GA₆₂. By direct comparison of mass spectra, the antheridiogen of A. mexicana was also determined to be different from the antheridiogens of Anemia phyllitidis (L.) Swartz, Anemia hirsuta (L.) Swartz and Lygodium japonicum (Thunb.) Sw.Abbreviations GA(s) gibberellin(s) - GA_a gibberellin A_n - GC-FT/IR combined gas chromatography-Fourier transform/infra-red spectrometry - GC-MS combined gas chromatography-mass spectrometry - IR intra-red spectrometry - KRI Kovats Retention Index - m/z mass/charge - TLC thin-layer chromatography - TMSi trimethylsilyl     

On Dark-Germination and Antheridium Formation in Anemia phyllitidis

Schraudolf's finding is confirmed that gibberellic acid induces antheridia in Anemia phyllitidis and Lygodium japonicum. The activity spectra of gibberellic acid and the native antheridiogen of Anemia phyllitidis are similar: Both induce antheridia in the tested species of the family Schizaeaceae but are inactive towards the tested representatives of other fern families. However, the native antheridiogens of two schizaeaceous species are more species-specific in their action than is gibberellic acid. Anemia medium cancels the light requirement for spore germination as is the case with gibberellic acid. Chromatographic studies indicate that the dark-germination-inducing factor is identical with, or very similar to, the earlier demonstrated antheridiogen. The specificities of the active factors towards dark-germination in A. phyllitidis and L. japonicum are similar to those encountered with antheridium formation. Anemia medium induces dark-germination and induces antheridia on the dark-grown protonemata to a concentration ca. 30 times lower than it induces antheridia on light-grown prothalli. The studies indicate that this differential activity results from a differential competence of the prothalli to react to the active substance in light and darkness.     

Factors Affecting Spore Germination of Volvariella volvacea

Environmental factors affecting basidiospore germination were studied with Volvariella volvacea, the edible straw mushroom which is common in South East Asia. A relatively mild heal shock is necessary for spore germination. The spores give best germination at 40°C although early hyphal growth is better at 35°C the germination of spores is affected by temperature. pH. a presoaking treatment and spore density. Higher pH supports more germination but seems unfavourable for early mycelial growth. Presoaking treatment in phosphate buffer solution or distilled water also stimulates germination markedly.     

Effects of Gibberellins and Their Methyl Esters on Dark Germination and Antheridium Formation in Lygodium japonicum and Anemia phyllitidis

The effects of GA₃, GA₄ and GA₉ and their methyl esters on darkspore germination and antheridium formation of the ferns Lygodiumjaponicum and Anemia phyllitidis were investigated. Althoughall induced both germination and antheridium formation in Lygodium,only the gibberellins induced these effects inAnemia. (Received August 28, 1986; Revision received November 14, 1986. )     

变异鳞毛蕨的孢子培养与配子体发育研究

应用无菌培养和常规泥土培养两种方法对变异鳞毛蕨(Dryopteris varia)孢子进行了比较研究,并在光学显微镜下观察了其配子体的发育过程.结果表明:蔗糖浓度为2%的1/2MS与MS培养基对孢子萌发时间和萌发率影响不大,但前者较适于孢子萌发,而后者则适于孢子体形成;在1/2MS培养基上,1%的蔗糖浓度比其它浓度更适宜于孢子的萌发.以菜园士为培养基质时,变异鳞毛蕨孢子的萌发时间短且萌发率高,但幼孢子体出现的时间明显晚于无菌培养.孢子萌发为书带蕨型,原叶体发育为三叉蕨型,符合鳞毛蕨属配子体发育的特征.     

Aminooxyacetic acid inhibits antheridiogenesis and development of Anemia phyllitidis gametophytes

Cytomorphological studies of the development of young fern gametophytes (Anemia phyllitidis) have been used to investigate combined effects of gibberellic acid and ethylene on male sex expression. ACC (the key by-product in ethylene biosynthesis pathway) was found to exert a synergetic effect on the gibberellic acid-induced antheridia formation, and this phenomenon could be related with the specific stimulation of cell growth and activity of their differentiation. To complete and verify those observations male sex expression in the fern gametophytes treated with ACC-biosynthesis inhibitor was reinvestigated. Aminooxyacetic acid (AOA) restrained antheridia formation via inhibition of cell divisions. AOA influenced the arrangement and flexibility of cellulose microfibrils in the antheridial zone cells, thus affecting cell expansion. On the other hand, the level of DNA synthesis was not reduced. Transient increase in the number of S-phase cells, followed by the accumulation of G2-phase cells led to the enhancement of cell polyploidization. All these findings correspond with the previous observations and support participation of ethylene in gibberellic acid-induced male sex expression in ferns.Abbreviations AOA Aminooxyacetic acid - CPA Cell profile area - GA Gibberellin - GA₃ Gibberellic acid     

中华缩叶藓孢子萌发与原丝体发育特征研究

通过室内人工培养中华缩叶藓的孢子,在光学显微镜下详细观察了其孢子萌发、原丝体发育及配子体发生的全过程.结果表明:中华缩叶藓的孢子在壁内萌发,随后分裂产生块状原丝体;块状原丝体上可产生两种丝状体,一种是具疣的棒状原丝体,另一种是由长圆柱状细胞组成的轴丝体;配子体原始细胞只产生于块状原丝体上.根据中华缩叶藓的孢子萌发和原丝体发育特征,并参照Nishida对藓类植物孢子萌发类型的划分,确定中华缩叶藓的萌发孢子型应属于缩叶藓型(Ptychomitrium-type).     

Factors Affecting the Rate of Heat-induced Spore Germination in Dictyostelium discoideum

Washed spores of Dictyostelium discoideum, strains NC-4H, NC-4D, and V-12, germinated rapidly after being heat shocked at or near 45.0 C for 30 min. Cultures of the slime molds were grown in association with Escherichia coli B/r as the host bacterium; spores taken from plates of synthetic medium had a higher final germination value than spores from complex medium containing peptone and yeast extract. Young spores germinated more rapidly than older spores. Optimal germination occurred between pH 6.0 and 7.0, and, of the buffers tested, potassium phosphate allowed the most rapid germination. After heat shocking, spores were diluted into fresh oxygenated buffer to provide enough oxygen for completion of germination. Germination occurred most rapidly between incubation temperatures of 22 and 25 C.     

蕨类植物孢子萌发及原叶体发育的观察

以腐叶土为培养基质,对21种蕨类植物进行了孢子萌发和原叶体发育的研究,结果表明：①不同时期播种的同种蕨类的孢子,发育出原叶体和幼孢子体所历经的时间长短不同;②孢子萌发和配子体生长发育的适宜温度约为15～24℃;⑨稀有蕨类的孢子萌发率低,而在野外能形成较大种群的蕨类的孢子萌发率高;④用GA3处理孢子可以促进萌发;⑤当原叶体上长出幼孢子体时,原叶体由大变小,由绿变黄,21种蕨类的原叶体都在幼孢子体上长出第3片叶时消失;⑥幼孢子体上长出的第1、2片叶在形态上与以后长出的叶不同;⑦孢子萌发需要光;⑧1片原叶体尽管有多个颈卵器,但仅发育出1株幼孢子体;⑨利用腐叶土进行蕨类孢子繁殖是一种经济实用的繁殖方法。     

Microsporogenesis, Pollination, Pollen Germination and Male Gametophyte Development in Taxus brevifolia

Taxus brevifolia(Nutt.), commonly known as Pacific or westernyew, is a conifer native to the Pacific northwest of North America.Contrary to other Taxus species, T. brevifolia staminate strobiliare usually located on 2-year-old foliage although they mayoccur on foliage from 1 to 5-years-old. This delayed staminatestrobilus development may be an adaptation to the low lightenvironment where T. brevifolia grows. Microsporogenesis occurredin the autumn preceding pollination. Successive divisions producedisobilateral tetrads visible as early as mid-October. Over-winteringstaminate strobili usually contained separate microspores. In1996 to 1999, pollination occurred in March and April in twonatural forest sites on southern Vancouver Island, British Columbia,Canada. The low amounts of airborne pollen and prolonged pollinationperiod indicated low pollination success within T. brevifolia.Female receptivity was measured by the presence of a pollinationdrop. Protandry up to 18 d was observed. In vitro pollen germinationwas moderate to good, ranging from 65 to 88% depending on thetree and year. DAPI fluorescence staining showed successfulmale gametophyte development in vitro. The microspore dividedforming a tube nucleus and generative cell within 3 d of culture.The generative cell then divided forming a sterile nucleus andspermatogenous nucleus after 17 d. The spermatogenous nucleusacquired a cell wall then divided forming two equal sperm after24 d. Copyright 2000 Annals of Botany Company Taxus brevifolia, Pacific yew, microsporogenesis, pollination, pollen germination, male gametophyte development     

苔藓植物孢子萌发与原丝体发育研究进展

孢子萌发与原丝体发育对于研究苔藓植物以及其他植物类群的系统发育与系统演化有着十分重要的作用。本文综述苔藓植物孢子萌发类型、原丝体发育特征以及环境影响因子等,还介绍了20世纪90年代以来该领域研究的新进展,如人们以苔藓植物原丝体为实验材料进一步揭示Ca2+·CAM信号系统、、植物激素、光信号系统等在植物体内的作用机制。     

苔藓植物孢子萌发与原丝体发育研究进展

孢子萌发与原丝体发育对于研究苔藓植物以及其他植物类群的系统发育与系统演化有着十分重要的作用。本文综述苔藓植物孢子萌发类型、原丝体发育特征以及环境影响因子等,还介绍了20世纪90年代以来该领域研究的新进展,如人们以苔藓植物原丝体为实验材料进一步揭示Ca2 ．CAM信号系统、植物激素、光信号系统等在植物体内的作用机制。     

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.     

Activity of Antheridiogen from the Fern Anemia phyllitidis in Three Flowering Plant Bioassays

Pure samples of the antheridiogen of Anemia phyllitidis (A_An) were tested for their ability to affect the growth of dwarf corn (d₅) and lettuce seedlings, and to influence α-amylase production by barley half-seeds. Stimulation of dwarf corn growth and barley amylase production was, on a molar basis, from 1/2 to 1/250 that given by GA_3. In lettuce, A_An had a synergistic effect with low levels of GA₃; alone, A_An was inhibitory or ineffective. Therefore, in addition to having a close chemical resemblance to gibberellin, A_An induces similar, but not identical physiological responses in flowering plants as well as ferns.