Comparative morphological studies on spikes of Indian Selaginella Beauv.

The present study provides a comparative morphological analysis of spikes in different Indian species of Selaginella. The salient features of spikes including their types and also the shape and margin of sporophylls of the closely related taxa are characteristically useful in taxonomic delineation. We have used the term Leaf-flap, for the first time, and the Sporophyll-pteryx to denote the occurrence of vertical/oblique projection on the dorsal surface of leaf and sporophyll, respectively. The shape and colour of both mega- and micro-sporangia are also helpful in taxonomy; however, their size is not much significant as these are variable within the same spike of the species. A new pattern of sporangial distribution is being reported for the first time in the spike of S. plana (Desv. ex Poir.) Hieron.     

A large‐scale phylogeny of the lycophyte genus Selaginella (Selaginellaceae: Lycopodiopsida) based on plastid and nuclear loci

The lycophyte genus Selaginella alone constitutes the family Selaginellaceae, the largest of the lycophyte families. The genus is estimated to contain 700–800 species distributed on all continents except Antarctica, with highest species diversity in tropical and subtropical regions. The monophyly of Selaginella in this broad sense has rarely been doubted, whereas its intrageneric classification has been notoriously contentious. Previous molecular studies were based on very sparse sampling of Selaginella (up to 62 species) and often used DNA sequence data from one genome. In the present study, DNA sequences of one plastid (rbcL) and one nuclear (ITS) locus from 394 accessions representing approximately 200 species of Selaginella worldwide were used to infer a phylogeny using maximum likelihood, Bayesian inference and maximum parsimony methods. The study identifies strongly supported major clades and well resolves relationships among them. Major results include: (i) six deep‐level clades are discovered representing the deep splits of Selaginella; and (ii) 20 major clades representing 20 major evolutionary lineages are identified, which differ from one another in molecular, macro‐morphological, ecological and spore features, and/or geographical distribution.     

A Study of the Evolutionary Relationships of Fundulus Topminnows (Teleostei: Fundulidae)

A hypothesis of the evolutionary relationships of thirty-fourspecies of Fundulus and their closer relatives is presented.The study is restricted to morphological characters which couldbe determined to be primitive or derived using the methods ofphylogenetic systematics. Following Parenti, a family Fundulidaeis recognized. It is composed of four genera of North Americankillifishes. (Cyprinodontidae as usually constitutedis polyphyletic.)No convincing characters demonstrate that Fundulus is a naturalgroup (a monophyletic group). However, all species of Fundulusshare four derived characters with Lucania. The sister group(closest genealogical relative) of Fundulus plus Lucania isa group composed of the genera Adinia and Leptolucania. Fourmonophyletic groups of Fundulus can be recognized based on sharedderived characters: (1) subgenus Fundulus (seven species excludingthree species placed in Fontinus); (2) subgenus Fonlinus (sixspecies); (3) subgenus Xensima (five species); and (4) subgenusZygonectes (thirteen species). Three species, F. (Plancterus)zebrinus, F. lima, and F. parvipinnis are of uncertain affinitieswithin the Lucania-Fundulus clade     

中国局限蚊属的研究(双翅目：蚊科)

中国局限蚊属的研究（双翅目：蚊科）龚正达（云南省流行病研究所大理６７１０００）陆宝麟（军事医学科学院微生物流行病研究所北京１００８５０）局限蚊属（ＴｏｐｏｍｙｉａＬｅｉｃｅｓｔｅｒ,１９０８）是煞蚊族中的一个小属,主要分布在东洋界的印马亚界,已知近４...     

越南莲座状复苏卷柏一新种——越南卷柏(卷柏科)

该文描述了在越南发现的卷柏科一新种——越南卷柏(Selaginella pseudotamariscina X. C. Zhang & C. W. Chen)。经过分子系统发育分析并与近缘种形态比较,认为该新种是卷柏属(Selaginella)同穗亚属(subg. Stachygynandrum)的一个物种,与S. digitata-S. imbricata分支为姐妹群关系。该新种与卷柏(S. tamariscina)和垫状卷柏(S. pulvinata)的形态近似,其植株均为莲座状,但不同之处在于中叶对称,似披针形,上表面具1沟槽; 孢子叶穗略压扁; 孢子叶和营养叶性状和排列近似,孢子叶非同形,略异形,正置,腹面孢子叶大于背面孢子叶; 背面孢子叶败育,孢子囊仅见于腹面孢子叶基部。     

Diel vertical migration in Mesocyclops edax: implications for predation rate estimates

The diel migration patterns of Mesocyclops edax and its preyin a small lake were followed in two studies separated by approximatelyone year. Gut contents of the predators were examined and selectivityindices calculated at each depth at 0100 h during 1980. Thethree principal zooplankton prey found in the guts of M. edaxwere Keratella, Kellicottia, and Bosmina. The predator and allthree major prey species exhibited unique and different dielvertical distribution and migration patterns. The complex natureof the spatio-temporal variation in prey density to which M.edax is exposed, demonstrates the dangers of using selectivityindices without knowledge of the distribution patterns of bothpredator and prey. An increase in vertebrate predation pressurefrom one year to the next is thought to be responsible for anincrease in the abundance of small zooplankton species, thedisappearance of two out of three of the large zooplankton species,and the onset of a pronounced nocturnal migration pattern inthe third large species. ¹Present address: Biology Department, Williams Hall #31, LehighUniversity, Bethlehem, PA 18015, USA     

基于mtDNA和rDNA基因序列的中国按蚊属塞蚊亚属种类的系统发育研究（双翅目：蚊科）

【目的】应用mtDNA和rDNA基因特征重建中国按蚊属塞蚊亚属已知种类的系统发育关系, 以阐明亚属内各蚊种的亲缘关系。【方法】对采自中国的按蚊属塞蚊亚属Anopheles (Cellia) 20种蚊的mtDNA-COⅡ和 rDNA-28S-D3序列进行测定和分析, 以按蚊属按蚊亚属Anopheles (Anopheles)的中华按蚊An. (An.) sinensis和赫坎按蚊An. (An.) hyrcanus为外群, 采用COⅡ和D3单基因, 以及“COⅡ+D3”联合数据组以邻接法（NJ）、 最大简约法（MP）、 最大似然法（ML）和贝叶斯法（BI）等重建这些种类的系统发育树。【结果】 mtDNA-COⅡ和rDNA-28S-D3序列的长度范围分别为685 bp和375～410 bp, 在塞蚊亚属蚊种间的遗传距离分别为0.015～0.117和0.003～0.111。各系统树显示外群被合理分开,除在COⅡ树中新塞蚊系为并系外,各系均聚为单系群,新迈蚊系和迈蚊系亲缘关系最近。联合数据组构建的系统合意树显示中国塞蚊亚属各蚊种形成4支,除伪威氏按蚊与多斑按蚊种团未聚为单系群外,其他各种团和复合体成员种均分别聚在一起,各分支的置信值均大于50%。【结论】本研究获得的分子系统发育树清楚地显示了中国按蚊属塞蚊亚属各种类及系之间的系统发育关系, 对其分类和防治研究具有参考价值。     

Microsatellite cross-species amplification in the genus Littorina and detection of null alleles in Littorina saxatilis

Microsatellite DNA is widely used as population genetic marker,but the cost of using microsatellites is high, as they usuallyneed to be developed and optimized for each species separately.Cross-species amplification of microsatellites is thereforecommonly applied to bring down the cost, but it can also involvegenotyping errors. We studied cross-species amplification ofmicrosatellites in four species of the Atlantic group of Littorina(Neritrema): L. saxatilis (Olivi, 1792), L. obtusata (Linnaeus,1758), L. fabalis (Turton, 1825) and L. arcana Hannaford Ellis,1978 to investigate whether markers originally developed fora more distantly related Pacific species [L. subrotundata (Carpenter,1864)] suffered from more amplification problems than markersdeveloped for one of the species in the Atlantic group (L. saxatilis).We also compared variation in amplification success among thespecies and among different regions in the NE Atlantic. Approximatelyhalf of the 12 primers developed for L. subrotundata and theseven primers developed for L. saxatilis were successfully amplifiedin other species of the subgenus. The success was dependenton phylogenetic distance among species within the subgenus.On the other hand, the variation in performance of the locibetween geographically remote populations of the same specieswas as high as variation among the species. In earlier studiesstatistical analyses indicated that several loci showed a heterozygotedeficiency due to null alleles. The presence of null alleleswas confirmed by a segregation analysis of the microsatelliteloci in eight half-sib families of L. saxatilis. (Received 2 April 2007; accepted 19 November 2007)     

Leaf Survival and Evolution in Betulaceae

Studies on the changes in leaf number of 12 species of Betulaceaewere carried out by repeated observations during several years.The inner structure of the winter buds of these species wasalso examined. The periods of leaf emergence were long in Alnusand Betula, intermediate in Corylus and short in Ostrya andCarpinus. A heavy summer leaf fall is characteristic only ofthe Gymnothyrsus subgenus of Alnus. One lamina and two stipulesis the basic unit constituting the winter buds. Only the budsof Gymnothyrsus are composed of several of these units. In theAlnaster subgenus of Alnus, Betula and Corylus, there are oneor two scales that seem to have originated from the two stipulesremaining after reduction of the lamina. Eight and 24 scalesof similar origin were found in Ostrya and Carpinus respectively.A common ancestral species having the following primitive charactersis proposed: shoot constituted only of the equal-sized units,period of leaf emergence long, and leaf fall usually occurs.Alnus (Gymnothyrsus) is assumed to be the most primitive typeas it has many characters similar to those of the proposed ancestralspecies. Carpinus is assumed to be the most advanced group.The leaf survivorship curve is assumed to have changed fromthe primitive bell-shaped to an advanced trapezoid concurrentwith an increase in the number of bud scales. Betulaceae, Alnus, Betula, Carpinus, Corylus, Ostrya, leaf survival, leaf emergence, stipules, winter buds, evolution     

ANATOMY OF SOME PILL CLAMS (BIVALVIA: PISIDIOIDEA) FROM AFRICA, WITH THE DESCRIPTION OF NEW TAXA

The anatomy of 4 species of pisiid clam sampled in Ethiopia,Zimbabwe and South Africa was studied. The new species Pisidiumethiopicum is described, including the Ethiopian form regardedearlier as a variety of P. casertanum (Poli). P. incomitatumKuiper is included in the genus Musculium as type species ofa new subgenus Pseudopisidium. Anatomical characters of PisidiumkenianumPreston and P. langleyanum Melvill & Ponsonby arealso discussed. (Received 22 March 1994; accepted 23 August 1994)     

RADULAR TEETH OF INDO-PACIFIC MOLLUSCIVOROUS SPECIES OF CONUS: A COMPARATIVE ANALYSIS

Species determination in the gastropod genus Conus, heretoforeexclusively based on shell morphology and color pattern, hasled to considerable uncertainty and disagreement. We proposethat qualitative and quantitative radular tooth characters arepotentially useful in differentiating species as well as geographicsubspecies and will improve the taxonomic base. Molluscivorousspecies of Conus, sometimes placed in the subgenera Cylinder, Textilia,Darioconus, and the nominal subgenus, are taxonomically amongthe most difficult. We thus examined intra- and interspecificvariation in radular morphology of 11 of these species, C. ammiralis,C. araneosus, C. bandanus, C. canonicus, C. episcopatus, C. marmoreus,C. nodulosus, C. omaria, C. pennaceus, C. textile, and C. victoriae,and intra- and interregional variations in radular morphologyof C. pennaceus from three geographic regions. Taxonomicallyuseful qualitative characters include presence/absence of one ortwo barbs and a blade, and whether the row of denticles comprisingthe serration is continuous or interrupted. Useful metric charactersinclude the ratios of first barb, second barb, blade, serration,shaft width and base width to tooth length, the ratio of toothlength to shell length, the ratio of shaft width to base width,and the degree of curvature of the teeth. Univariate analysisof variance (ANOVA and unplanned pairwise comparison tests)distinguished 53 of the 55 possible species pairs from eachother by at least one character. Multivariate analysis of variance (MANOVA)indicated statistically significant differences between thespecies in the other two pairs. In C. pennaceus, ANOVA and unplannedpairwise tests differentiated Hawaiian from Indian Ocean samples,and MANOVA differentiated those from Maldives and Sumatra. Thediscrete radular characters sort the 11 species into three groups,and these are consistent with the distribution patterns of thequantitative characters. Radular tooth characters are thus potentiallyuseful in differentiating species and subspecies and shouldbe combined with other character sets in generating future phylogenetichypotheses. ¹ Present address: Department of Pathobiology, University of Pennsylvania,019104-6068, USA ² Author for correspondence: e-mail: kohn{at}washington.edu (Received 23 October 1999; accepted 25 January 1999)     

LIFE HISTORIES AND GROWTH OF THE GASTROPODS BITTIUM RETICULATUM AND BARLEEIA UNIFASCIATA INHABITING THE SEAWEED GELIDIUM LATIFOLIUM

Bittium reticulatum and Barleeia unifasciata are two of themost abundant microgastropods inhabiting the alga Gelidium latifoliumin the North of Spain. Bittium reticulatum produces one cohortannually, born in August, and living over two years. Barleeiaunifasciata shows two population groups, each one formed bytwo cohorts. There are important differences in density andgrowth rate between the two groups. The two species are separatedspatially on Gelidium. Bittium reticulatum prefers to live atthe base of the plant and Barleeia unifasciata prefers the upperpart. There are different demographic patterns in each population.This fact supports the concept of distribution in compartmentsrelative to intertidal systems. Each compartment favours differentdemographic patterns (Received 10 February 1987;     

Early Leaf Development and Leaf Sheath Formation of Botrychium strictum and B. virginianum (Ophioglossaceae)

The morphogenesis of the leaf sheath was studied in Botrychiumstrictum and B. virginianum of subgenus Osmundopteris. In thetwo species, the leaf primordium is initiated on the lowestpart of a ridge which is formed by partial growth of the shootapex. The leaf primordium first grows to cover the shoot apexalmost entirely except for a slit-like opening. The openingis formed by the frontal rim of the growing leaf primordium,i.e. the leaf margin, and the rear part of the shoot apex. Asthe leaf grows, the leaf margin elongates and takes a reverseV-shape. On both lateral edges of the leaf margin, marginalgrowth occurs to form the lobes of the leaf sheath. Such marginalgrowth and a small amount of growth on the uppermost portionof the sheath is involved in the leaf sheath formation in B.cirginianum, while only marginal growth takes place in B. strictum.The leaf sheath of Botrychium virginianum, in comparison tothat of B. strictum, has a morphogenesis which is more similarto the completely covering leaf sheath of subgenera Botrychiumand Sceptridhim. Based on the morphogenesis of the leaf sheath,systematic relationships in subgenus Osmundopteris are discussed Botrychium virginianum, B. strictum, subgenus Osmundopteris, leaf ontogeny, leaf sheath formation, scanning electron microscopy, light microscopy     

海南七仙岭7种卷柏属植物的微观形态与生境间的关系分析

为探讨生境对卷柏属(Selaginella)植物微观形态的影响,利用扫描电子显微镜对海南七仙岭采集的7种卷柏属植物的侧叶、中叶、孢子叶的叶表皮形态以及小孢子形态进行全面观察分析,并计算气孔器大小、气孔密度、孢子大小等,比较分析其微观形态的区别及微形态与生境间的关系,为卷柏属植物的分类提供依据。结果显示:(1)同种卷柏属植物的侧叶、中叶与孢子叶在叶表皮形态上具明显差异,尤其是孢子叶上的气孔与营养叶相对较小且稀疏,与孢子叶的繁殖功能相符合。(2)不同种卷柏属植物的叶表皮特征也明显不同,主要表现在叶缘刺、气孔和瘤状突起上,表明这些特征可以作为卷柏属植物种间区分的依据。(3)卷柏属植物的小孢子形态稳定,纹饰多样;部分种间的小孢子形态相似,但可通过纹饰类型、裂缝的曲直进行区分。(4)琼海卷柏的小孢子具有独特的网状纹饰,暗示其具有独特的演化途径。(5)卷柏属植物叶表皮的气孔特征、瘤状突起特征,小孢子的颜色、纹饰,与海拔、生境的湿度有一定的相关性,但其形成机理有待进一步研究。     

A NEW SPECIES OF OXYCHILUS FROM THE LIGURIAN APENNINES (ITALY) (PULMONATA: ZONITIDAE)

A new species of Oxychilus Fitzinger from the Ligurian Apennines(Italy) is described. The new species is particularly characterizedby its penial complex which has a very slender proximal peniswith variable inner sculpture and a widened distal penis. Theproximal penis inner structure consists of a series of longitudinalpleats which may often be crenulated, undulated or fragmentedto form rows of papillae, providing new evidence to supportthe opinion that this is not a valid diagnostic character forseparating Oxychilus into the nominal subgenus and OrtiziusForcart. Consequently Ortizius is herein proposed as a juniorsynonym of Oxychilus s. str. (Received 5 July 1990; accepted 4 March 1991)     

Characterization and physical mapping of ribosomal RNA gene families in Plantago

• Background and Aims The organization of rRNA genes incultivated Plantago ovata Forsk. and several of its wild allieswas analysed to gain insight into the phylogenetic relationshipsof these species in the genus which includes some 200 species. • Methods Specific primers were designed to amplify theinternal transcribed spacer (ITS1 and ITS2) regions from sevenPlantago species and the resulting fragments were cloned andsequenced. Similarly, using specific primers, the 5S rRNA genesfrom these species were amplified and subsequently cloned. Fluorescencein-situ hybridization (FISH) was used for physical mapping of5S and 45S ribosomal RNA genes. • Results The ITS1 region is 19–29 bp longer thanthe ITS2 in different Plantago species. The 5S rRNA gene-repeatingunit varies in length from 289 to 581 bp. Coding regions arehighly conserved across species, but the non-transcribed spacers(NTS) do not match any database sequences. The clone from thecultivated species P. ovata was used for physical mapping ofthese genes by FISH. Four species have one FISH site while threehave two FISH sites. In P. lanceolata and P. rhodosperma, the5S and 45S (18S-5·8S-25S) sites are coupled. • Conclusions Characterization of 5S and 45S rRNA geneshas indicated a possible origin of P. ovata, the only cultivatedspecies of the genus and also the only species with x = 4, froma species belonging to subgenus Psyllium. Based on the studiesreported here, P. ovata is closest to P. arenaria, althoughon the basis of other data the two species have been placedin different subgenera. FISH mapping can be used as an efficienttool to help determine phylogenetic relationships in the genusPlantago and show the interrelationship between P. lanceolataand P. lagopus.     

Phylogenetic Analysis and Karyotype Evolution in the Genus Clivia(Amaryllidaceae)

Phylogenetic relationships of five taxa of Clivia, one probablenew species plus four recognized species, and three outgroupspecies were studied using sequences of the nuclear ribosomal5S non-transcribed spacer and the internal transcribed spacer(ITS) of 45S rDNA. Analysis of the data sets separately generatedsome well-supported groupings and congruent phylogenies. Cliviaminiata and C. gardenii are closely related. ‘Robust Gardenii’,the putative new species, is a sister clade of this group. Clivianobilis is distantly related to these three taxa and C. caulescensoccupies an intermediate position between the two groups. Chromosomelocations and distribution patterns of the 5S nuclear ribosomalgene in the species of Clivia were investigated using fluorescenceinsitu hybridization (FISH). In all species, only one pair of5S rDNA signals was observed. These were located on the shortarm of chromosome 8, at the position of the interstitial C-bands.The phylogenies obtained from the DNA sequences together withthe chromosome data accumulated here and previously publishedinformation on the location of the 45S rDNA sites have beenused to postulate evolutionary trends in Clivia chromosomes.Copyright 2001 Annals of Botany Company Clivia, chromosome evolution, 45S and 5S rDNA, ITS, FISH, molecular phylogeny     

On the Ecology of Coexistence in Parthenogenetic and Bisexual Lizards of the Genus Cnemidophorus

In the center of their distribution in North America, membersof a complex of parthenogenetic and bisexual lizards of thegenus Cnemidophorus may be found side by side with one or moreof the others in a bewildering variety of patterns and ecologicalassociations. Exactly why so many congeneric species are foundliving together and exactly what their ecological, physiologicaland geographical requirements are remains virtually unknown.Here 1 summarize all reported cases of sympatry among six speciesof Cnemidophorus and discuss in detail specific examples ofsome of these interactions based on several years of field collectionsand observations. In addition I present the first field experimentalstudy designed to understand the ecological relationships ofsympatry in Cnemidophorus.     

Nuclear DNA Amounts in Pteridophytes

DNA amounts (C-value and genome size) are much-used biodiversitycharacters. A workshop held at Kew in 1997 identified majorgaps in our knowledge of plant DNA amounts, recommending targetsfor new work to fill them. Murray reviewed non-angiosperm plantsnoting that representation of pteridophyte species (approx.0.42%) was poor, while locating C-value data for them was verydifficult. The workshop confirmed the need to make data forother groups besides angiosperms accessible for reference purposes.This paper pools DNA C-values for 48 pteridophyte species fromeight original sources into one reference source, and fulfilsa key workshop recommendation for this group. Comparing thesedata shows that nuclear 1C-values in pteridophytes vary approx.1000-fold, from 0.055 pg in Selaginella species to about 55pg in Ophioglossum petiolatum. Genome size estimates for 25pteridophytes vary approx. 200-fold from 0.055 to 10.7 pg, andthe mean genome sizes in diploids and polyploids (5.15 and 4.59pg, respectively) are not significantly different. Wider comparisonsshow that ranges of genome sizes in the major groups of landplants are very different. Those in bryophytes and pteridophytesare narrow compared with those in gymnosperms and angiosperms.The data indicate that the origin of land plants possibly involveda first major increase in genome size in the evolution of vascularplants, while a second such increase occurred later in gymnosperms.C-values for pteridophytes remain very few, but conversely opportunitiesfor new work on them are many. Copyright 2001 Annals of BotanyCompany Pteridophyte DNA amounts, DNA C-values, nuclear genome sizes     

The process of evolutionary migration in species of Selaginella

The variation in three species ofSelaginella that occur in areas south and north of glaciated and periglacial regions is analysed. In each species the southern populations are more variable than the northern ones. These geographic patterns of variation are related to post-Wisconsin climatic changes and to the northward migration of each species. The geographic differentiation and migration of the species are seen as related phenomena. The concept of evolutionary migra tion-the operation of natural selection and of migration in mutually supportive roles-is discussed and applied to the examples inSelaginella. The possible broad significance of the process of evolutionary migration in floras directly under the influence of Wisconsin and post-Wisconsin environments is indicated.