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。     

五种藓类植物的孢子萌发与原丝体发育

本文对中华缩叶藓(Ptychomitrium sinense)、狭叶缩叶藓(P.linearifolium)、威氏缩叶藓(P.wilsonii)、葫芦藓(Funaria hygrometrica)和立碗藓(Physcomitrium sphaericum)5种国产藓类植物的孢子萌发和原丝体发育进行研究,结果表明不同藓类孢子萌发和原丝体发育类型不同,孢子萌发和原丝体发育方式与藓类植物的生态环境有关.     

五种藓类植物的孢子萌发与原丝体发育

本文对中华缩叶藓(Ptychomitrium sinense)、狭叶缩叶藓(P. linearifolium)、威氏缩叶藓(P．wilsonii)、葫芦藓(Funaria hygrometrica )和立碗藓(Physcomitrium sphaericum ) 5种国产藓类植物的孢子萌发和原丝体发育进行研究, 结果表明不同藓类孢子萌发和原丝体发育类型不同, 孢子萌发和原丝体发育方式与藓类植物的生态环境有关。     

中国藓类植物孢子萌发和原丝体发育的初步研究

关于苔藓植物的孢子萌发(Spore Germination)和原丝体发育(ProtonemaDevelopment)的研究,对阐明苔藓植物的各分类群之间的关系和种系发生及系统演化等有重要意义。虽然早在1782年J. Heduing就报告过藓类植物的原丝体形态,但后来长时间内研究较少,直到20世纪50年代开始增多了研究者从事本项工作。到1978年     

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).     

碎米藓属两种藓类植物孢子萌发与原丝体发育特征研究

为获取其孢子萌发类型与该属植物系统发育、生态选择以及生殖策略选择的相关性,该研究通过室内人工培养的方式,在微米量级下观察并描述了碎米藓属(Fabronia)碎米藓(F.pusilla)和东亚碎米藓(F.matsumurae)两种藓类植物孢子萌发、原丝体发育和配子体发生的过程.结果表明:(1)两种藓类植物孢子均为壁外萌发...     

葫芦蘚的培养观察

葫芦藓(Funaria hygrometrica Hedw.)是常见的苔藓植物。无论在郊外或市区,只要是有机质丰富而阴湿的土壤上,都容易找到。它们分布广泛,井具有藓类植物的典型特征,故在植物学教学中都将葫芦藓做为苔藓植物门中藓纲植物的主要代表来介绍。葫芦藓的生活史具有两个世代,即配子体世代和孢子体世代,配子体世代开始于孢子,孢子先萌发为绿色的丝状体,叫做原丝体,再由原丝体的若干部位上产生许多芽体,每个芽体长成一株具有茎叶的植物体。又     

三种植物生长调节剂对密叶绢藓(Entodon challengeri)孢子萌发、原丝体发育及芽体发生的影响

研究了3种植物生长调节剂苯基噻二唑基脲(TDZ)、6-苄基腺嘌呤(6-BA)、萘乙酸(NAA)对密叶绢藓[Entodon challengeri(Paris)Cardot]孢子萌发、原丝体发育及芽体发生的影响,并对整个发育过程进行了显微观察和照相,结果表明:(1)3种植物生长调节剂对密叶绢藓孢子萌发影响不显著;(2)在原丝体发育阶段,1.0 mg/LNAA对原丝体初期的发育促进效果显著,0.4 mg/L TDZ对原丝体发育中期分枝的形成促进效果显著,6-BA处理效果不显著;(3)3种植物生长调节剂单独处理均促进芽体的发生,但0.4 mg/L TDZ效果最佳。而1.5 mg/L 6-BA+TDZ组合处理效果更加显著;(4)芽体的发生数量与芽体的长势无正相关性。     

光照和温度对尖叶拟船叶藓孢子萌发及原丝体发育的影响

用组织培养法和光学显微镜技术初步研究了光照和温度对尖叶拟船叶藓孢子萌发及原丝体发育的影响。结果表明：（1）光照是影响孢子萌发的主要环境因子,20℃环境下,24h光照4d的孢子萌发率达83.3％;温度下黑暗培养的孢子30d也不能萌发,转光照后4d的萌发率可达84.6％;（2）温度是影响原丝体发育的主要环境因子,连续光照下,20℃的原丝体生长最快、分枝最多、分化最早,第31天可长达651.64μm;25℃次之,只有379.12μm;而自然光照下5-10℃环境下的孢子萌发率（18d为70.2％）和原丝体生长速度（127.44μm）均最慢;（3）原丝体发育到一定阶段,断裂为单个细胞,单个细胞再萌芽出新原丝体。     

三种植物生长调节剂对密叶绢藓（Entodon challengeri）孢子萌发、原丝体发育及芽体发生的影响

研究了3种植物生长调节剂苯基噻二唑基脲(TDZ)、6-苄基腺嘌呤(6-BA)、萘乙酸(NAA)对密叶绢藓[Entodon challengeri(Paris)Cardot]孢子萌发、原丝体发育及芽体发生的影响,并对整个发育过程进行了显微观察和照相,结果表明:(1)3种植物生长调节剂对密叶绢藓孢子萌发影响不显著;(2)在原丝体发育阶段,1.0 mg/LNAA对原丝体初期的发育促进效果显著,0.4 mg/L TDZ对原丝体发育中期分枝的形成促进效果显著,6-BA处理效果不显著;(3)3种植物生长调节剂单独处理均促进芽体的发生,但0.4 mg/L TDZ效果最佳。而1.5 mg/L 6-BA TDZ组合处理效果更加显著;(4)芽体的发生数量与芽体的长势无正相关性。     

Migration of prospindle before the first asymmetric division in germinating spore of Marchantia polymorpha

The development of the plant body starts with spore germination in bryophytes. In many cases, the first division of the spore occurs after germination and cell elongation of the spore. In Marchantia polymorpha, asymmetric division occurs upon spore germination to generate two daughter cells: the larger one retains the ability to divide and develops into the thallus via sporeling or protonema, while the smaller one maintains tip growth and differentiates into the first rhizoid, providing a scaffold for initial development. Although spore germination of M. polymorpha was described in the 19th century, the intracellular processes of the first asymmetric division of the spore have not been well characterized. In this study, we used live-cell imaging analyses to elucidate microtubule dynamics during the first asymmetric division concomitantly with germination. In particular, we demonstrated that the preprophase band was not formed in the spore and that the bipolar prospindle, which is a microtubule structure surrounding the nucleus during prophase, migrated from the center to the periphery in the spore, suggesting that it was the earliest visible sign of cell polarity. We also showed that the occurrence of asymmetric division depended on actin filaments. Our findings regarding the first division of the spore in M. polymorpha will lead to a better model for cell-autonomous asymmetric division in plants.     

金灰藓(Pylaisiella polyantha)配子体发生的实验观察

金灰藓Pylaisiella polyantha (Hedw．)Grout孢子在光照培养箱中进行培养,实验组为含有Knop培养液的琼脂培养基质,对照组为无营养成分的琼脂培养基质。在光学显微镜下对配子体发生进行了观察、描绘和照相。结果表明：实验组和对照组孢子萌发所需时间相同,均为53．5h,萌发极相为1～4极。4d时,实验组萌发率为85．4％,对照组为54．1％;20d时,开始形成配子体芽原基;40d时,形成具假根、茎、叶的配子体,并形成两性器官。并对配子体发生过程的特点进行了分析和讨论。     

金灰藓(Pylaisiella polyantha)配子体发生的实验观察

金灰藓Pylaisiella polyantha(Hedw.)Grout孢子在光照培养箱中进行培养,实验组为含有Knop培养液的琼脂培养基质,对照组为无营养成分的琼脂培养基质。在光学显微镜下对配子体发生进行了观察、描绘和照相。结果表明:实验组和对照组孢子萌发所需时间相同,均为53.5h,萌发极相为1～4极。4d时,实验组萌发率为85.4%,对照组为54.1%;20d时,开始形成配子体芽原基;40d时,形成具假根、茎、叶的配子体,并形成两性器官。并对配子体发生过程的特点进行了分析和讨论。     

梨蒴珠藓孢子萌发与原丝体发育特征研究

为了解梨蒴珠藓（Bartramia pomiformis）孢子萌发和原丝体发育特征,在显微镜下观察室内人工培养的梨蒴珠藓单倍配子体发育过程。结果表明,梨蒴珠藓孢子吸水膨胀5 d后,开始破壁萌发,原丝体系统以丝状绿丝体为主,轴丝体在绿丝体上分化产生。培养22 d后,配子体在轴丝体细胞上分化产生。参照Nishida的标准,梨蒴珠藓孢子萌发类型为真藓型（Bryum-type）。这为梨蒴珠藓的人工扩繁提供了发育学基础资料。     

Dry/wet cycling reduces spore germination and viability in six peatland bryophytes

• Dry/wet cycling driven by water level fluctuation in wetlands may strongly influence the destiny of seeds. However, how dry/wet cycling affects spore survival and germinability in peatland bryophytes is poorly understood.
• Six peatland bryophytes, three hummock- and three hollow-dwelling Sphagnum species, were chosen as study species. We tested the effects of dry (60% air RH)/wet (waterlogging) cycle frequency (once per 12, 8 or 4 days for low, medium or high, respectively) and ratio (3:1, 1:1 or 1:3 dry:wet time per cycle) on spore germinability, viability, dormancy percentage and protonema development.
• Dry/wet cycling significantly reduced spore germination percentage and viability and slowed protonema development in all Sphagnum species, being more pronounced with higher dry/wet cycling frequencies. The hummock species S. capillifolium and S. fuscum had higher spore germination percentage after the continuous dry treatment, while the hollow species S. angustifolium, S. squarrosum and S. subsecundum showed the opposite response, compared to the continuously wet treatment. Except for S. squarrosum, spore viability was higher after the dry than after the wet treatment. Spore viability and dormancy percentage were higher after a dry/wet ratio of 1:3 than after ratios of 3:1 and 1:1.
• Our study shows that both germinability and viability of bryophyte spores are reduced by dry/wet cycling (especially when frequent) in peatlands. This emphasizes the need to ensure constant water levels and low frequencies of water level fluctuation, which are relevant in connection with wetland restoration, to promote Sphagnum spore survival and establishment in peatlands after disturbances.