广西蕨类植物分布新记录

报道广西蕨类植物分布新记录8种,即细毛碗蕨、黑柄铁角蕨、湖南黔蕨、双胞耳蕨、台湾耳蕨、柔软耳蕨、尾叶石韦和龙骨星蕨。列出这些种的标本引证、地理分布和分类特征等。     

Mediterranean island biogeography: Analysis of fern species distribution in the system of islets around Sicily

Abstract

The aim of this article was to test the way in which geographical factors influence island floras in the Mediterranean basin, using ferns as target organisms, and the islands surrounding Sicily as location. A matrix with presence/absence data concerning fern taxa in the 16 islands studied was compiled. Cluster analysis, principal co-ordinates analysis (PCoA), principal components analysis (PCA) and a Bayesian analysis were performed. For each island, the total number of fern taxa was regressed against three factors: island area, island elevation and isolation. All the analyses pointed to affinities between islands according to their different geological composition, independently from their geographic position. A clear positive island species/area relationship (ISAR) was shown only for the volcanic islands. The island species/(area×elevation) relationship (ISAER), on the contrary, was unsatisfactory. The main features of interest are the following: (1) the clear division of the islands into two groups, volcanic vs. sedimentary; (2) the floristic richness of the volcanic compared to sedimentary islands and (3) the uniqueness of the pteridophyte flora of Pantelleria. This seems to demonstrate that the lower number of taxa in the islands farthest away from the “mainland” (Sicily, Tunisia) is not due to isolation, but due to another factor, probably habitat availability.     

Assessing occurrence and habitat of Ophioglossum vulgatum L. and other Ophioglossaceae in European forests. Significance for nature conservation

Ophioglossum vulgatum has been discovered in several Lorraine forests with numerous populations on Keuper clay substrata. In all these forests, it occurs in the same plant community type, a hygrophilic oak-ash forest belonging to the Carpinion alliance. O. vulgatum is present in all stages of the forest cycle, but it is most abundant in young succession stages. This misrecognized forest habitat of O. vulgatum represents a primary habitat for this species and also a refuge, in which it is much less threatened than in wet grassland ecosystems. A review is given of all published data related to this Ophioglossum in European forests and comparisons are made with the occurrence of other European Ophioglossaceae in forest communities, in particular Botrychium virginianum in boreal and subalpine forests and B. matricariifolium in montane and lowland forests.     

华中铁角蕨复合体的生物系统学研究

变异铁角蕨系(series Variantia Ching et S.H.Wu)主产我国,形态变异大.在标本室中,铁角蕨属(AspleniumL.)的鉴定非常紊乱,同一个种名下往往存在着不同的细胞型或杂种.本文通过对该复合体的生物系统学研究,揭示它们在网状进化中亲缘关系的来龙去脉,并对它们的分类学位置提出讨论和处理建议.细胞学、等位酶、形态学和孢粉学证据表明:由3个基本的二倍体祖先种形成了共13个成员组成的华中铁角蕨复合体(Asplenium sarelii com-plex).华中铁角蕨(Asplenium sarelii Hook.)应当被标定为二倍体,以往文献中所谓的四倍体"华中铁角蕨"实际上是来自二倍体华中铁角蕨和细茎铁角蕨(A.tenuicaule Hayata)杂交后加倍得来的异源四倍体产物,它被另外处理为新种武当铁角蕨(A.wudangense Z.R.Wang et X.Hou).北京铁角蕨(A.pekinense Hance)是二倍体华中铁角蕨加倍后得来的同源四倍体.泸山铁角蕨(A.lushanense C.Chr.)是云南铁角蕨群中的惟一二倍体祖先种,不应处理为四倍体云南铁角蕨(A.yunnanense Franch)的异名.变异铁角蕨(A.varians Wall.ex Hook.et Grey.)很可能是细茎铁角蕨的同源四倍体.3个天然四倍体新杂种及其起源被发现,它们是:龙门铁角蕨(A.×longmenense(=A.pekinense×vzrians)),京云铁角蕨(A.×jingyunense(=A.pekinense×yunnanense))和吉多铁角蕨(A.× kidoi(=A.pekinense×wudangen.se)).另外3个天然三倍体新杂种也被发现并给出了推断的亲本,他们是华武铁角蕨(A.×huawuense(=A.sarelii×wudangense)),泸云铁角蕨(A.×luyunense(=A.lushanense×yunnanense))和细变铁角蕨(A.×tenuivarians(=A.tenuicaule×varians)).本文阐明了华中铁角蕨复合体成员间在网状进化中的错综复杂关系,同时表明等位酶比较结合细胞学观察是揭示多倍体和杂种起源的有效工具.     

20种药用蕨类植物提取液抑菌试验研究

以20种药用蕨类植物提取液对金黄色葡萄球菌、大肠杆菌、八叠球菌、变形杆菌、枯草杆菌、酵母菌进行抑菌活性研究,结果表明,20种蕨类提取液至少对一种供试微生物具有抑菌活性。样品蕨类醇提液比水提液具更强的抑菌活性,供试菌有阳性结果的水提液,平均抑菌圈直径10.12mm,而醇提液则为11.92mm。试验结果还表明,药用蕨类对枯草杆菌抗菌活性效果最明显,对酵母菌效果最差。不同蕨类植物其地上部分和地下部分抑菌效果不尽相同。     

Changes in the cryptogam flora of the Wealden sandrocks, 1688–1984

The cryptogam flora of 15 sandrock sites in the central Weald, U.K. was assessed and compared with previous records beginning in 1688. A total of 264 species was recorded (29 algae, 90 lichens, 165 bryophytes and eight ferns) of which 18 lichens, 21 bryophytes and one fern were not relocated. Air pollution, changes in the microclimate brought about by invasion of trees and shrubs and trampling appear to be the main cause for the decline in the flora, although over-collection of rarities was also a factor.