Phylogeny of Ptychostomum （Bryaceae,Musci） inferred from sequences of nuclear ribosomal DNA internal transcribed spacer （ITS） and chloroplast rps4

The phylogeny of Ptychostomum was first spacer （ITS） region of the nuclear ribosomal （nr） DNA DNA rps4 sequences. Maximum parsimony, maximum undertaken based on analysis of the internal transcribed and by combining data from nrDNA ITS and chloroplast likelihood, and Bayesian analyses all support the conclusion that the reinstated genus Ptychostomum is not monophyletic. Ptychostomum funkii （Schwagr.） J. R. Spence （≡ Bryum funkii Schwaigr.） is placed within a clade containing the type species of Bryum, B. argenteum Hedw. The remaining members of Ptychostomum investigated in the present study constitute another well-supported clade. The results are congruent with previous molecular analyses. On the basis of phylogenetic evidence, we agree with transferring B. amblyodon Mull. Hal. （≡ B. inclinatum （Brid.） Turton≡ Bryum archangelicum Bruch ＆ Schimp.）, Bryum lonchocaulon Mull. Hal., Bryum pallescens Schleich. ex Schwaigr., and Bryum pallens Sw. to Ptychostomum.     

骨生苔藓在中国的新记录(英文)

在四川省马边大风顶国家级自然保护区的高山草甸上发现了生长在牦牛骨头上的苔藓。共有四种藓类植物:真藓科的真藓、刺叶真藓、丛藓科的短叶小石藓以及葫芦藓科的中华葫芦藓,它们都是顶蒴藓类。这是骨生苔藓植物在中国的首次记录报道。     

拟纤枝真藓(Bryum petelotii)的地理新分布与分类地位探讨

报道了中国大陆新记录种——拟纤枝真藓(Bryum petelotii Thér.et Henr.)在贵州、云南的分布;描述了本种的形态特征和地理分布,并讨论了本种与相近种真藓(Bryum argenteum Hedw.)和纤枝短月藓［Brachymenium exile(Doz.et Molk.) Bosch et Lac.］的关系;基于文献和相关标本的研究,阐述并讨论了Ochi H.和B.C.Tan等关于该种分类地位的观点,并赞同将拟纤枝真藓置于真藓属(Bryum Hedw.)的观点。     

Morphological characteristics of fruits of Fagopyrum (Polygonaceae) from China

Macro- and micro-morphological characteristics of fruits in eight species and one variety of the genus Fagopyrum Mill. (Polygonaceae) from China were observed under stereoscope and scanning electron microscope(SEM). Based on the results, the fruits of the species studied are divided into type Ⅰ , Ⅱ and Ⅲ. The fruits of type Ⅰ are triangular-pyramidal; their surface are rugosely reticulate, neither smooth nor shiny. Two species, F. tataricum and F. dibotrys have this fruit type. Those of type Ⅱ are ovoid-triangular-pyramidal; their surface are smooth and shiny, and striately reticulate. Three species, F. esculentum, F. statice and F. lineare, have this fruit type. In type Ⅲ, the fruits are ovoid-triangular-pyramidal; their surface are smooth and shiny, and covered with many warty grains and sparsely finely striate. F. urophyllum, F. gracilipes, F. leptopodum var. leptopodum, and F. leptopodum var. grossii have this fruit type. Judging from the morphological characteristics of fruits, F. dibotrys might be more closely related to F. tataricumthan to F. esculentum.     

Spore morphology of pteridophytes from China Ⅱ. Sinopteridaceae

Spores of 61 species and 6 varieties in 9 genera of the Sinopteridaceae were examined under scanning electron microscope (SEM). Based on surface ornamentation and other features, the spores of the Sinopteridaceae are divided into three types. In type Ⅰ , the exospore is smooth and the surface ornamentation, which is reticulate, cristate, echinate or rugate, is formed by the perispore. All the other genera of this family, except for Onychium and Cryptogramma, have this pattern of spores. In type Ⅱ, the surface ornamentation is formed by both perispore and exospore. This pattern is found only in Cryptogramma. In type Ⅲ, the perispore is thin and the surface ornamentation is formed by the exospore. Onychium is characterized by this type of spores. Those genera with spores of type Ⅰ of the Sinopteridaceae seem to be closely related to each other and should be natural members of this family. The systematic position of Cryptogramma and Onychium, with spores of type Ⅱ and type Ⅲ respectively, however, should be reconsidered. Aleuritopteris might be the mostprimitive member of the Sinopteridaceae from the evidence of spore morph     

沿海岛屿与内陆藓类植物遗传多样性和分化的比较研究——以真藓(Bryum argenteum Hedw.)为例

基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓（Bryum argenteum Hedw.）的遗传多样性进行了研究。结果显示：岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度（G_st=0.453）大于内陆居群（G_st=0.387）,岛屿居群的遗传分化与地理来源间存在极显著相关性（r=0.478,n=175,P<0.001）。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29.4%~29.7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。     

沿海岛屿与内陆藓类植物遗传多样性和分化的比较研究——以真藓(Bryum argenteum Hedw.)为例

基于11个内陆居群和32个岛屿居群的252份标本,采用ISSR分子标记技术对真藓( Bryum argenteum Hedw.)的遗传多样性进行了研究。结果显示:岛屿与内陆居群间的遗传多样性差异显著,岛屿居群间的分化程度( G st = 0. 453)大于内陆居群( G st = 0. 387),岛屿居群的遗传分化与地理来源间存在极显著相关性( r = 0. 478, n = 175, P < 0. 001)。地理隔离效应是导致岛屿居群间遗传分化的重要因素。岛内居群间的遗传分化水平较低,仅有29. 4%~ 29. 7%的遗传多样性存在于居群间。聚类分析表明,43个居群可划分为10大类群,真藓遗传关系受地理因素和生境异质性的影响,水域隔离影响了真藓繁殖体在岛屿间的传播。     

A Cytological Observation on Six Mosses of Northeast China

In this paper the chromosome number of 6 mosses species are reported. The materials used for investigation were taken from immature capsules. Meiosis in spore mother cells were observed, and the results are as follows: Brachythecium plumosum, n=15. Entodon obtusatus, n = 11. E.okamurae, n = 11. Anoectangium aestivum, n= 13. Bryum argenteum, n= 10. Eurhynchium eustegium, n = 20+ 2m. The chromosome number of the former three species are re-ported for the first time.     

Spore morphology of pteridophytes from China Ⅲ. Thelypteridaceae 1. Cyclosorus Link.

Spore morphology of 51 species of Cyclosorus in the Thelypteridaceae from China was investigated using scanning electron microscopy (SEM). The spores are monolete, bilaterosymmetric, ellipsoidal in polar view, and kidney-shaped in equatorial view. On the basis of the variation in their surface ornamentation, the spores fall into three main types. Type I: The surface of spores is echinate or perforate with fimbriate wings. 19 species belong to this type. Type Ⅱ: The surface of spores is cristate. 11 species belong to this type. Type Ⅲ: The surface of spores is echinulate. 10 species belong to this type. The remaining 11 species have spores with mixed surface ornamentation of the above three types, which are considered as intermediate types. The results are valuable for a better understanding of the taxonomy and palynology of the genus Cyclosorus.     

Biological and environmental characteristics of three cosmopolitan mosses dominant in continental Antarctica

Abstract. Bryum argenteum, B. pseudotriquetrum and Ceratodon purpureus are the predominant mosses in Victoria Land, continental Antarctica. All have cosmopolitan distributions and are widespread throughout Antarctica with wide ecological amplitudes resulting in considerable morphological variation. They are well adapted to tolerate the physiological stresses imposed by the severe environment. This study investigates aspects of their growth, physiology and survival in response to habitat constraints, especially hydrology. Their distribution is controlled almost exclusively by moisture availability. Each species tends to predominate in a specific zone along hydrological gradients, with B. pseudotriquetrum on moist soil, C. purpureus on drier soil, and B. argenteum on unstable stream margins, fluvial deposits and the marginal capillary zone. Where conditions are optimal, each species can form a turf 6–10 cm thick. Nutrient status of the soil does not appear to be an important determinant in the distribution pattern within communities. The thermal regime of the moss turf varies according to its moisture content; for a period of ca. six weeks during the summer, with the frequent long spells of 24-h sunshine, temperatures remain above 0 °C for much of the time even though air temperatures are frequently below the freezing point. This allows growth and metabolic activity to proceed continuously at a relatively rapid rate for quite long periods. Annual shoot incremental growth can exceed 3.5 mm in each species. Growth of B. argenteum may be inhibited by UV- B radiation. The optimal temperature for photosynthesis in each species is around 15 °C, but significant carbon fixation occurs at 5 °C. Photosynthetic rates at 5, 10 and 20 °C were B. argenteum > B. pseudotriquetrum > C. purpureus.     

The discovery of triploid Lycoris sprengeri Comes ex Baker from Anhui,China

Lycoris sprengeri Comes ex Baker is endemic to China. Reported in the present paper are the chromosomes number and karyotypes for two wild populations of the species from Anhui. ( 1 )Caishi population has a karyotype 2n=33=9st+21t+3T. The length of chromosomes ranges from 5.58～9.15μm. The karyotype belongs to Stebbin’s (1971) “4A”. (2)Longyashan populations have two karyotypes. The karyotype formula of the type I is 2n=22=8st+14t, with chromosomes ranging from 6.88～9.15μm. The karyotype belongs to “4A”. The karyotype formula of the type Ⅱ is 2n＝22＝1m+1sm+14st+6t, with chromosomes ranging from 7.20～15.80μm. The karyotype belongs to “3B”. The triploid type of L. sprengeri was discovered in Anhui for the first time. The karyotype 2n=22 =1m+1sm+14st+6t in diploid type of this species is here reported for the first time.The Robertsonian change plays a key role in karyotype evolution of Lycoris.     

Notes on the Chinese Brachytheciaceae (II)

From 1896 to 1898, Carolo Mueller published thirteen Chinese species in the genus Brachythecium based on Jos. Giraldi’s collections from Shaanxi Province made during 1890～1896. They are B . campylothallum , B . amnicolum , B . homocladum , B . pinnirameum , B . permolle , B . glauco-viride, B . garovaglioides, B . viridefactum, B . glauculum, B . perminusculum, B . dicranoides , B . micrangium and B . thraustum . In this paper, holotypes of nine species, isotypes of three species, and one specimen which was examined by Mueller himself and referred to as B . thraustum by him, were studied. As a result, B . permolle and B . glauco-viride are reduced to B . rivulare as synonyms, B . wichurae is reduced to B . garovaglioides, B . micrangium is transferred to the genus Okamuraea as an independent species, i. e. O. micrangia (C. Muell. ) Wanget Hu, and the remaining 9 species are still recognized as species in the genus Brachythecium.     

Comparative anatomy of oil cells and mucilage cells in the leaves of the Lauraceae in China

The distribution density of oil cells, the morphology and structure of both oil and mucilage cells, and their localization in the mesophyll of 112 species, 5 varieties and 2 forms in 21 genera of the Lauraceae are comparatively studied with the methods of tissue clearing and paraffin sectioning. The results show that there exist obvious differences of the distribution density of oil cells among the species in the Lauraceae. The presence of oil cells and mucilage cells is found to be a marked anatomical feature of the leaves in most of the plants in the Lauraceae. Their distribution in the mesophyll can be divided into 4 types: type Ⅰ , in which only oil cells are present; type Ⅱ, in which both the oil and mucilage cells are present; type Ⅲ, in which only mucilage cells are present; type Ⅳ, in which neither oil cells nor mucilage cells are present. The distribution density of oil cells, the distribution types of oil cells and mucilage cells and their localization in the mesophyll are of some taxonomic value at the specific level in the Lauraceae. In the whole Lauraceae or in some large genera, the evolutionary trend of the distribution types of oil cells and mucilage cells might be as follows: type Ⅰ → type Ⅱ →type Ⅲ →type Ⅳ. The characteristics of the 4 distribution types of oilcells and mucilage cells support the division of two subfamilies in the Lauraceae.     

固定沙丘结皮层藓类植物多样性及固沙作用研究

 根据对沙坡头固定沙丘生物结皮的物种调查、鉴定及盖度和生物量的研究,藓类植物共2科,7属,16种,以真藓（Bryum argenteum）为优势种。随着固沙时间的延长,生物结皮中藓类和藻类总盖度呈上升趋势;沿不同年代固定沙丘坡面向上等距离梯度,藓类盖度显著下降,而藻类盖度则平稳上升。对不同年代固定沙丘生物结皮优势种真藓的生物量和固沙量的测定表明,随沙丘固定年代的增加,真藓的生物量和固沙量增加,50年代固沙区结皮层真藓生物量是944.03 kg·hm-2,固沙量是3.925×104 kg·hm-2,但固沙率随时间的增加而减少。真藓的饱和吸水量与生物量呈正相关,50年代固定沙丘藓类结皮层可吸水7.06×103 kg·hm-2,说明藓类结皮层具有很强的吸水和保水能力,对于干燥少雨的沙漠地区具有十分重要的生态学意义。     

Morphological Identification of Elymus sibiricus,E. nutans,and E. burchan-buddae,and Their Genomic Relationships

In order to investigate morphological variations of Elymus sibiricus L., E. nutans Griseb., and E. burchan-buddae (Nevski) Tzvelev ［=Roegneria nutans (Keng) Keng］, and to explore their systematic relationships, six morphological characters were measured and compared between the Elymus species. Interspecific hybridizations between E. nutans and E. sibiricus, and E. burchan-buddae were carried out with the aid of embryo rescue. Chromosome pairing behaviour was also analysed at metaphase- I of meiosis in pollen mother cells of F₁ hybrids. Morphologic characters, such as length of spikes and length of glumes varied considerably between different individuals of each species, whereas length and width of paleas were quite stable and different between species. The interspecific hybrids were completely sterile and their meioses were irregular. Meiotic configuration of E. nutans × E. burchan-buddae was 7.70I +13.40Ⅱ+0.06Ⅲ+0.08 IV, whereas that of E. sibircus×E. nutans was 11.98I+9.61Ⅱ+0.64Ⅲ+0.39Ⅳ+0.01V. It is concluded from the morphological and cytological study that (1) it is possible to identify the three Elymus species using the palea character, in addition to other traditionally applied characters; (2) Elymus nutans and E. burchan-buddae have a comparatively high genomie relationship, while E. nutans and E. sibircus have a relatively low genomic affinity to one another; and (3) a certain chromosome pairing regulator was presented in the hybrid between E. burchan-buddae andE. nutans.     

Systematics and morphological evolution within the moss family Bryaceae: a comparison between parsimony and Bayesian methods for reconstruction of ancestral character states

The Bryaceae are a large cosmopolitan moss family including genera of significant morphological and taxonomic complexity. Phylogenetic relationships within the Bryaceae were reconstructed based on DNA sequence data from all three genomic compartments. In addition, maximum parsimony and Bayesian inference were employed to reconstruct ancestral character states of 38 morphological plus four habitat characters and eight insertion/deletion events. The recovered phylogenetic patterns are generally in accord with previous phylogenies based on chloroplast DNA sequence data and three major clades are identified. The first clade comprises Bryum bornholmense, B. rubens, B. caespiticium, and Plagiobryum. This corroborates the hypothesis suggested by previous studies that several Bryum species are more closely related to Plagiobryum than to the core Bryum species. The second clade includes Acidodontium, Anomobryum, and Haplodontium, while the third clade contains the core Bryum species plus Imbribryum. Within the latter clade, B. subapiculatum and B. tenuisetum form the sister clade to Imbribryum. Reconstructions of ancestral character states under maximum parsimony and Bayesian inference suggest fourteen morphological synapomorphies for the ingroup and synapomorphies are detected for most clades within the ingroup. Maximum parsimony and Bayesian reconstructions of ancestral character states are mostly congruent although Bayesian inference shows that the posterior probability of ancestral character states may decrease dramatically when node support is taken into account. Bayesian inference also indicates that reconstructions may be ambiguous at internal nodes for highly polymorphic characters.     

石漠化干旱环境中石生藓类水分吸收特征及其结构适应性

苔藓是荒漠植被演替过程中常见的先锋植物,同时也是极端恶劣环境的开拓者。比较石漠化地区常见的穗枝赤齿藓(Erythrodontium julaceum(Schwaegr.)Par.)、反叶扭口藓(Barbula fallax Hedw.)和真藓(Bryum argenteum Hedw.)对干旱环境的适应性,为石漠化环境的恢复和治理提供理论依据。结果表明:最大持水能力和保水率穗枝赤齿藓和反叶扭口藓均大于真藓。3种苔藓的吸水过程包括外吸水和内吸水,吸水动力学曲线均表现为S型饱和曲线,但吸水特征存在较大差异;穗枝赤齿藓和反叶扭口藓的饱和吸水量相差甚微,但远大于真藓,前两者约为后者的2.5倍;最大总、内、外吸水速度穗枝赤齿藓分别为真藓的3.41、2.52倍和3.02倍,反叶扭口藓分别是真藓的2.79、2.52倍和3.55倍。茎的解剖学结构显示真藓和反叶扭口藓有明显的中轴,属内导水型藓类,而穗枝赤齿藓无中轴,属外导水型;但严格的内导水型植物是不存在的,不少植物属于混合导水型,这与环境水分高低有关。因此,中轴的有无并不是导致吸水能力强弱的决定性因素,还与苔藓所处的环境状况、生长型、毛细管系统类型和茎叶结构密切相关。     

Accumulation of DNA damage in Antarctic mosses: correlations with ultraviolet-B radiation, temperature and turf water content vary among species

The susceptibility of three East Antarctic moss species to UV-B radiation was examined by measuring accumulation of cyclobutane pyrimidine dimers under natural sunlight during the austral summer season of 2002/03. The 2002/03 season was characterized by unusually low springtime ozone depletion and as such our results likely underestimate the DNA damage possible in a more typical UV-B radiation season. Despite this all three species accumulated significant DNA photoproducts. We also found a positive association between photoproduct accumulation and incident UV-B radiation in the two cosmopolitan species, Bryum pseudotriquetrum and Ceratodon purpureus , with more DNA damage in samples collected early in the season compared with later in the summer. For B. pseudotriquetrum , negative associations were also observed between photoproduct accumulation and both turf water content and the 10-day mean air temperature. Photoproduct accumulation in the endemic species Schistidium antarctici was similarly high across the season and no significant association with environmental variables was found. Our results are consistent with the two cosmopolitan species having somewhat higher UV-B-screening capabilities and possibly more efficient mechanisms for repairing DNA damage than the endemic S. antarctici .     

22种假瘤蕨属植物孢子纹饰超微特征

利用扫描电镜对假瘤蕨属2系、5亚系22种植物的孢子纹饰特征进行了研究.结果显示:该属孢子为单裂缝、两侧对称,极面观为椭圆形,赤道面观为肾形.表面纹饰具有6种类型:光滑、粗糙、颗粒、棒状、疣状和瘤状纹饰以及它们之间的过渡类型.研究表明,孢子纹饰特征可以用来区分该属中的近缘种,但不能用以界定假瘤蕨属的属下分类--系和亚系.     

Phenological studies on British mosses

Abstract

Seasonal patterns of reproductive development are reported for the five British mosses Atrichum undulatum, Bryum argenteum, Grimmiapulvinata, Polytrichum alpestre and Tortula muralis, and vegetative phenology is also described for B. argenteum and P. alpestre. Clearly defined seasonal cycles of gametangial and sporophytic development characterize P. alpestre, and the cycles in Britain resemble those previously reported for polar populations of this species. The seasonal timing of the later stages of sporophytic development, and of spore release, was shown to be relatively constant within each species but the gametangial cycles and fertilization periods appear to be more variable than in P. alpestre in the weedy colonist, B. argenteum, and particularly in the lithophytes, G. pulvinata and T. muralis.