Morphological variation in populations of Bletia purpurea (Orchidaceae) and description of the new species B. riparia

Bletia purpurea is the most widespread species in its genus. Morphological variation has been recognized throughout the range of its distribution. In this paper, the morphological variation from 63 populations (583 individuals) ofBletia purpurea is assessed to determine whether more than one species were present. Forty-four quantitative and qualitative characters were examined by univariate analyses and exploratory multivariate analyses. Univariate analyses indicate that quantitative characters such as lateral sepal width, petal. width, lip length, and lip width are significantly different for populations from Acazónica, Mexico. Floral parts in the populations from Acazónica are the smallest among all populations. Qualitative characters such as petals covering the lip midlobe and horizontal lip position are found exclusively in the same populations. We concluded that these populations should be described as a new species,B. riparia. Multivariate analyses indicated that morphological variation among the other populations cannot be ascribed to geographic distribution or ecological factors.     

Genomic organization of ribosomal RNA genes in Bromus (Poaceae).

Restriction site maps of the rDNA genes of nine Bromus species are described. The rDNA repeat units ranged from 8.2 to 11.1 kbp in length. Intraspecific length variation was observed in the BamHI digestions in three of the nine species. Restriction site variation was observed mainly in the intergenic spacer (IGS) but was also detected in the coding region. A unique KpnI site was present in the IGS of Bromus tectorum and Bromus sericeus (subgenus Stenobromus); in addition, B. sericeus contained an extra EcoRI site. An additional DraI site was observed in the IGS of Bromus trinii (subgenus Neobromus). A BstEII site in the IGS, common to seven of the species, was absent in B. tectorum and B. sericeus. In the coding region, a 2.1-kbp BstEII fragment was present in four subgenera represented by Bromus inermis and Bromus erectus (subgenus Festucaria), Bromus marginatus and Bromus carinatus (subgenus Ceratochloa), B. tectorum and B. sericeus (subgenus Stenobromus), and B. trinii (subgenus Neobromus); a similar fragment of only 1.1 kbp was present in Bromus mollis and Bromus arvensis (subgenus Bromus). An additional BamHI site was present in the coding region of B. erectus. Ribosomal DNA data suggested that B. mollis and B. arvensis (subgenus Bromus) are genetically isolated from the other subgenera, which showed a derived relationship. Restriction site mapping of the rDNA genes could provide useful molecular data for species identification and population and evolutionary studies in Bromus. Key words : Bromus, ribosomal DNA, restriction maps, evolutionary relationships.     

Comparative morphometry as a diagnostic tool applied to species delimitation in the genus Gastridium P. Beauv. (Poaceae)

Based on critical examination of both fresh and dried specimens and a morphometric analysis of herbarium specimens we performed a comparative study of the three closely related Gastridium (Poaceae, Tribe: Poeae, Subtribe: Agrostidinae) species G. ventricosum, G. phleoides and G. scabrum collected in Italy. The study aimed to provide new diagnostic tools to improve the taxonomy of the genus and confirm species delimitation. Variation in floral morphology in the three species was explored using seven quantitative and ten qualitative characters measured on 318 spikelets, both awned and unawned. Statistical methods, including principal components analysis (PCA) and non‐metric multidimensional scaling (NMDS), were used. Numerical analyses showed a general distinctness of spikelets and florets, consistent with the three studied species, and revealed among and within species variation patterns in both spikelet types. Accordingly, the most informative quantitative characters appeared to be the width and length of glumes and the length of awns, useful to distinguish G. phleoides which has the narrowest glumes and longer awns than the other species, while G. scabrum has the widest glumes. The most informative qualitative characters appeared to be the presence/absence of thick hairs or minute tubercles on the upper side of the lemma. The autonomy of the three studied species was confirmed. The taxonomic significance of the results is briefly discussed, and notes on the species distribution are included. Some nomenclatural and taxonomic notes on G. scabrum, of which literature still showed evidence of a general unawareness, are provided.     

Genetic diversity in Mediterranean diploid and tetraploid Bromus L. (section Bromus Sm.) populations.

The levels of genetic diversity assessed from allozyme data were investigated in 25 populations of Mediterranean Bromus intermedius, B. squarrosus, B. lanceolatus, and B. hordeaceus from Algeria. The geographically restricted diploids B. intermedius and B. squarrosus displayed less genetic diversity (the mean population gene diversity of Nei (Hu) ranged from 0.03 to 0.12) than the widespread tetraploid colonizers B. lanceolatus and B. hordeaceus (Hu = 0.07-0.27). Deviations from Hardy-Weinberg expectations in diploid populations of B. intermedius and B. squarrosus were observed owing to heterozygote excess at several loci and suggested that these self-fertilizing species may have substantial amounts of allogamy. Tetraploid populations of B. lanceolatus and B. hordeaceus were largely homozygous at homologous loci and frequently exhibited intergenomic fixed heterozygosity in accordance with their alloploid origin. Genetic variation at the infraspecific level was mostly distributed within populations in the four species, B. hordeaceus showing the lowest level of interpopulation differentiation (Gst = 0.06) and the highest level of gene flow (Nm = 3.75). Consistent gene flows are in agreement with the strongest intercontinental invasive behaviour of B. hordeaceus. Less differentiation was reported in the literature among later introduced B. hordeaceus populations from England and Australia, indicating reduced differentiation under the process of colonization. Moderate divergence occured among the four taxa, with interspecific genetic identities ranging from 0.87 to 0.93. In spite of substantial genetic similarity, species were clearly differentiated, with each tetraploid being more closely related to a diploid: B. hordeaceus to B. squarrosus and B. lanceolatus to B. intermedius.     

Morphological variation among Betula nana (diploid), B. pubescens (tetraploid) and their triploid hybrids in Iceland

BACKGROUND AND AIMS: Introgressive hybridization between two co-existing Betula species in Iceland, diploid dwarf birch B. nana and tetraploid downy birch B. pubescens, has been well documented. The two species are highly variable morphologically, making taxonomic delineation difficult despite stable ploidy levels. Here an analysis is made of morphological variation within each ploidy group with an aim to establishing a reliable means to distinguish the species. METHODS: Plant materials were collected from 14 woodlands in Iceland. The plants were identified based on 2n chromosome numbers. Morphological variation in species-specific characters within each ploidy group was analysed qualitatively and quantitatively. The morphological index was based on eight discrete characters, whereas the multivariate analysis was based on nine leaf variables. KEY RESULTS: Of the 461 plants examined, 9.5 % were found to be triploid hybrids. The three ploidy groups were morphologically distinguishable but their variation overlapped. The diploid, triploid and tetraploid groups had average scores of 1.3, 4.1 and 8.3, respectively, in the morphology index scale from 0 (B. nana) to 13 (B. pubescens). A linear discriminant analysis also revealed significant separation among the three ploidy groups and the model assigned 96 % and 97 % of the B. nana and B. pubescens individuals correctly. The triploid hybrids were difficult to predict since only half of them could be assigned correctly. Leaf length was the most useful variable identifying triploid hybrids. Geographical patterns within the ploidy groups could partly be explained by differences in mean July temperature. CONCLUSIONS: Hybridization between B. nana and B. pubescens is widespread in Iceland. The species can be distinguished from each other morphologically, and from the triploid hybrids. The overlapping morphological variation indicates bidirectional introgression between the two species via triploid hybrids. Iceland could be considered a birch hybrid zone, harbouring genetic variation which may be advantageous in subarctic regions.     

A multivariate morphometric study of the iberian representatives of<Emphasis Type="Italic">Potentialla</Emphasis> sect.<Emphasis Type="Italic">Recta</Emphasis> (<Emphasis Type="Italic">Rosaceae</Emphasis>)

A multivariate analysis has been performed in order to study the polymorphisms of the three species ofPotentilla sect.Recta (Th. Wolf)Juzepchuk represented in the Iberian Peninsula:P. asturica Rothm.,P. hirta L. andP. recta L. The variability of 20 characters (quantitative, binary and qualitative) has been evaluated in 76 collections mostly from the Iberian Peninsula and from other European territories, but also from North America, and North Africa. The analyses performed provide support for the recognition of the three species. The most discriminant among the quantitative characters is the width of the long trichomes on the stem, and then the width of the long trichomes on the leaves and the maximum length of the long trichomes. The interval of number of carpels, presence or absence of short eglandular trichomes and the abundance of long eglandular trichomes (>3 mm) are the most discriminant ones among the qualitative ones. The taxonomical position ofP. asturica, which has been previously subordinated as a subspecies within the other two taxa, is discussed. Our results support a good delimitation of this taxon which, on the basis of the morphological characters studied by us, seems to be morphologically more close toP. hirta than toP. recta, but differs significantly from both. A key to the three species is provided.     

Spores of Serpocaulon (Polypodiaceae): morphometric and phylogenetic analyses

The morphometry and sculpture pattern of Serpocaulon spores was studied in a phylogenetic context. The species studied were those used in a published phylogenetic analysis based on chloroplast DNA regions. Four additional Polypodiaceae species were examined for comparative purposes. We used scanning electron microscopy to image 580 specimens of spores from 29 species of the 48 recognised taxa. Four discrete and ten continuous characters were scored for each species and optimised on to the previously published molecular tree. Canonical correspondence analysis (CCA) showed that verrucae width/verrucae length and verrucae width/spore length index and outline were the most important morphological characters. The first two axes explain, respectively, 56.3% and 20.5% of the total variance. Regular depressed and irregular prominent verrucae were present in derived species. However, the morphology does not support any molecular clades. According to our analyses, the evolutionary pathway of the ornamentation of the spores is represented by depressed irregularly verrucae to folded perispore to depressed regular verrucae to irregularly prominent verrucae.     

Quantitative variation within and among populations of Arabis serrata Fr. & Sav. (Brassicaceae)

Phenotypic and genetic variation within and among eight populations of Arabis serrata are documented in this study. This species shows great morphological variation throughout its geographical distribution in Japan. Plants are located in habitats with different types of soils and degree of disturbance. Half-sibs progenies from eight populations were collected and cultivated in a garden experiment. Nine morphological traits representing size and shape of rosette leaves were recorded. Univariate analyses of measured traits showed that phenotypic means differed among populations for all characters. Leaves of plants from disturbed habitats had the longest petioles (lanceolate) and plants from limestone habitats showed the most roundness in leaf shape (ovate). The northernmost populations always revealed the smallest leaves. Multivariate principal component analyses also showed that leaf shape and size varied among populations. The first three principal components explained 98.5% of the variation. Coefficients of variation had a very wide range and differed from one population to another. Some traits (e.g. leaf width/leaf length ratio) were consistently less variable while others (e.g. leaf area and petiole length) were more plastic. All traits had significant genetic variance in all populations. Intra-class correlation coefficients differed for most of the traits and each population presented a different range of values. Most of the leaf traits were intercorrelated in all the populations studied, although some populations were integrated more tightly for some traits. Populations of A. serrata are differentiated in phenotypic means but they display a mosaic of traits with slight morphological differences in each locality (i.e. a quantitative genetic variation). Some traits can be correlated to the habitats that they occupy but for some of them it is difficult to assign an actual adaptive value.     

Nomimoscolex suspectus n. sp. (Eucestoda: Proteocephalidea: Zygobothriinae) with morphological and molecular phylogenetic analyses of the genus

We describe a new species of Nomimoscolex from the Amazon siluriform fishes Brachyplatystoma filamentosum, B. flavicans and B. vaillanti. It differs from N. piraeeba in a lower mean number of testes, the paramuscular position of the vitelline follicles, the ovarian width/proglottis width ratio and the cirrus-pouch length/proglottis width ratio. Protein electrophoresis assays performed for 25 enzymatic systems showed that specimens of N. suspectus n. sp. from the three host species form a homogenous population which was genetically isolated from N. piraeeba and N. dorad. Moreover, the latter two species, synonymised by Rego (1991) because of their close morphological similarity, could be separated at eight loci. We thus restore N. dorad as a valid species. We finally examined the composition of the genus Nomimoscolex using DNA sequences from the 5.8S rRNA, ITS-2 and 28S rRNA nuclear ribosomal genes and a matrix of 24 morphological characters. Phylogenetic relationships were inferred for nine species of the genus, five members of other monticelliid genera and two outgroup species. The results of the phylogenetic analyses performed on morphological and molecular characters converged with those from allozyme studies and showed that N. suspectus, N. piraeeba and N. dorad clustered in a distinct clade that excluded other members of the genus. We therefore recognised them as an aggregate of species to reflect an isolation supported by both morphological and genetic data. Because relationships among the remaining Nomimoscolex representatives and other genera were generally poorly resolved, regardless of the database analysed, no action was taken to reorganise them into alternative groupings.     

Comparative Study of the Ploidy Series Bromus sterilis, B. diandrus and B. rigidus (Poaceae) Based on Chromosome Numbers, Morphology and Isozymes

Abstract: Chromosome numbers, morphological characters and isozymes of seven enzymes were studied to assess relationships between species of the Bromus diandrus-rigidus polyploid complex and the closely related species, B. sterilis. The four different cytotypes detected, 2n = 14, 28, 42 and 56, could be divided into two species: B. sterilis (2n = 14, 28) and B. diandrus (2n = 42, 56) by morphological features and isozymes. The shape of the scar of rachilla segments in the floret proved to be a suitable character for distinguishing the two species, but not the chromosomal races within species. The tetraploid shared homozygous isozyme phenotypes with diploid B. sterilis at all loci, except one, suggesting that it is autopolyploid. No diagnostic isozymes could be found to distinguish between hexa- and octoploid cytotypes in the B. diandrus-rigidus complex.     

The varieties of Bauhinia pottsii G. Don in Thailand (Leguminosae-Caesalpinioideae)

 Bauhinia pottsii G. Don, B. subsessilis Craib, B. velutina (Wall. ex Benth.) Baker, B. mollissima (Wall.) Prain, and B. decipiens Craib were recently recognized as five varieties of Bauhinia pottsii G. Don. They grow naturally in southern Myanmar, Thailand, Indochina and the Malay Peninsula. Bauhinia pottsii var. decipiens (Craib) K. Larsen & S. S. Larsen is endemic to Thailand and known only from the type collection, so it was omitted from this study. Quantitative and qualitative morphological characters were examined in 200 specimens using multivariate and univariate analyses to determine the taxonomic relationship among the four. Some variation in qualitative characters was found between the varieties which separated them as previously defined in Flora of Thailand. Forty-three quantitative characters were subjected to cluster analysis to allow an objective classification into groups. The groups were subsequently evaluated by a canonical discriminant analysis. It was found that these characters collectively support the four varieties as defined by qualitative characters. However, the close relationship of varieties mollissima (Wall. ex Prain) K. Larsen & S. S. Larsen and velutina (Wall. ex Benth.) K. Larsen & S. S. Larsen is observed. The linear discriminant function has an overall rate of 98.5% correct classification and is useful for variety classification. Among quantitative characters, petal-claw length and ovarystalk length together with some qualitative characters are useful for key construction to separate the four varieties. Received April 24, 2001 Accepted December 11, 2001     

Multivariate analysis of morphological and anatomical characters of Calophyllum (Calophyllaceae) in South America

Calophyllum (Calophyllaceae), previously placed in Clusiaceae, is easily recognizable by its opposite entire leaves with close parallel venation alternating with resin canals. However, distinction between species has been difficult, because of infraspecific variation in tepal and stamen number and resemblance among species that share similar habitats. Here, I report the results of multivariate analyses of morphological and anatomical characters for Calophyllum in South America, and provide a taxonomic treatment for the genus in South America, the first since that of Vesque in 1893. Thirteen preliminary morphogroups were identified. Thirty‐two morphological characters of the leaf, flower and fruit from 401 specimens, and 17 anatomical leaf characters from 45 specimens were measured and analysed using principal component analyses (PCAs) and discriminant analyses (DAs). PCAs were used to find groups and DAs were used to validate those PCAs that were potential groups. Two main subgroups were identified in the general analysis. Subgroup M1 has terete stems and smaller leaves and flowers than subgroup M2, which, instead, has quadrangular stems. Only subgroup M2 showed distinctive clusters in regional and local analyses. Distinctive clusters and morphological and anatomical characters helped us to recognize four species in South America, including a new species, Calophyllum pubescens sp. nov. . In addition, a new species, Calophyllum mesoamericanum sp. nov. , is described from Central America. © 2013 The Linnean Society of London,     

黄河下游湿地芦苇形态变异研究

 以水盐为主导生态因子,分析了黄河下游湿地芦苇(Phragmites australis)种群形态变异的水平与格局。对基径、株高、叶长、叶宽、节间长、节间数和穗长7个形态特征在15个种群中的变异分析表明：种群内个体间形态差异极显著,7个形态特征在种群内的变异系数从大到小依次为节间长（0.284 6）、叶宽（0.253 6）、穗长（0.244 9）、叶长（0.208 5）、基径（0.187 5）、节间数（0.176 3）、株高（0.165 7）; 7个形态特征在种群间的变异度从大到小依次为株高、叶长、节间长、叶宽、基径、节间数、穗长,但种群间形态的显著差异主要存在于滨州种群（BZH）、淡水种群（ZHG、DPH、NYH,土壤总盐度<0.1%）、盐生种群（HS01、HS02、HS03、HS04、HS05、DWL、KD、GD、LZH、LJ、DLH,土壤总盐度>0.3%）之间,在来自相似生境的种群间形态差异普遍不显著;7个形态特征均与水盐联合影响因子显著相关;以形态特征为基础的聚类分析将研究的15个种群分为显著不同的３类。因此,根据黄河下游湿地芦苇形态变异规律和分化特点,建议将该地区芦苇分为盐生芦苇、淡水芦苇、巨型芦苇3个形态类型。     

青藏高原褐背拟地鸦表型特征的性别差异与地理变异

将数值分类用于鸟类分类学研究时,对于雌雄的形态特征差异没有被重视,尤其是对于雌雄同形的鸟类。本文以雌雄同形的褐背拟地鸦Pseudopodoces humilis为材料,运用SPSSl0．0FORwINDOwS统计分析软件对108号褐背拟地鸦标本(51♀♀,57♂♂)的数量性状(体长、跗跖长、翅长、尾长、嘴宽、嘴高、上喙长、下喙长、嘴裂、第3趾爪长、第1趾爪长)的原始数据进行分析,结果表明雌、雄性状在翅长(n＝51,P＝0．012)和嘴高(n＝57,P＝0．043)上有明显差异,但在体长、跗跖长、尾长、嘴宽、上喙长、下喙长、嘴裂、第3趾爪长、第1趾爪长等数值特征上却没有明显的差异。所以在以后对于褐背拟地鸦的地理种群变异和亚种分化的研究中,翅长和嘴高两特征应该根据雌雄分别讨论。通过对不同性状量度和纬度的相关回归分析,发现在测量标本所涉及的采集地范围内,即主要在青藏高原东南部地区,褐背拟地鸦体长和雄乌的翅长在地理分布上随纬度的增加而变小,而其它性状特征没有明显的地理分布纬度上的变化。     

Relationship between song characters and morphology in New World pigeons

We studied the pattern of variation in song characters among 16 New World pigeon species belonging to different taxonomic groups defined by morphological characters. Structural, temporal and frequency characters of the song were analysed. Principal components analyses showed that species belonging to the same taxonomic group were also grouped together by their song characters. In addition, individuals were correctly assigned into taxonomic groups by discriminant function analyses in more than 87.8% of cases. These analyses also showed that more than 87.5% of the individuals could be correctly classified by species when all song characters were included. Correct classification of individuals by species and taxonomic groups dropped when character types were analysed separately, thus showing that structural, as well as temporal and frequency characters are fundamental to define species- and group-specific identities of New World pigeon's songs. Correspondence between patterns of vocal and morphological variation found in this study can be a consequence of evolutionary changes in morphology affecting song production, as for example body size changes that constrain the syrinx to produce certain acoustic frequencies.     

Determination of morphological variation in subspecies of Isatis glauca Aucher ex Boiss. from Central Anatolia

Isatis glauca Aucher ex Boiss. has four subspecies: glauca, galatica Y?ld?r?ml?, sivasica (Davis) Y?ld?r?ml? and iconia (Boiss.) Davis, naturally growing in Turkey. In this study, 77 accessions from nine I. glauca ssp. populations were characterised in terms of variation in morphological characters, including the number of branches per plant, plant height, diameter of stem base, diameter of middle stem, diameter of apical stem, width and length of fruit, length of fruit stalk, fruit shape, fruit base shape, fruit apices shape, loculus, ondulation, apical process of fruit, fruit weight, basal length of fruit, apical length of fruit, wing width of fruit, loculus length, loculus width, length of seed, dorsal width of seed, lateral width of seed and seed weight. The number of branches had the highest value of coefficient of variation (CV), 0.21–0.86, while the fruit width had the lowest value of CV 0.08–0.20. According to Pearson’s correlation and multiple regression analyses, eco-geographical factors had a substantial effect on morphological variation. A principal component analysis explained 90.61 % of morphological variation through the study of five extracted components. A dendrogram, which was constructed according to the between-group linkages method, based on squared Euclidean distances, represented a hierarchical cluster analysis of 77 accessions. The results of the principal coordinate analysis, which showed differentiation according to morphological characters between nine populations, were consistent with the dendrogram. Consequently, morphological variation of I. glauca ssp. and the significant effects of eco-geographical factors on its morphological variation were discussed.     

Morphological variability between wild populations and inbred stocks of a Chinese minnow, Gobiocypris rarus

Gobiocypris rarus, a small, native cyprinid fish, is currently widely used in research on fish pathology, genetics, toxicology, embryology, and physiology in China. To develop this species as a model laboratory animal, inbred strains have been successfully created. In this study, to explore a method to discriminate inbred strains and evaluate inbreeding effects, morphological variation among three wild populations and three inbred stocks of G. rarus was investigated by the multivariate analysis of eight meristic and 30 morphometric characters. Tiny intraspecific variations in meristic characters were found, but these were not effective for population distinction. Stepwise discriminant analysis and cluster analysis of conventional measures and truss network data showed considerable divergence among populations, especially between wild populations and inbred stocks. The average discriminant accuracy for all populations was 82.1% based on conventional measures and 86.4% based on truss data, whereas the discriminant accuracy for inbred strains was much higher. These results suggested that multivariate analyses of morphometric characters are an effective method for discriminating inbred strains of G. rarus. Morphological differences between wild populations and inbred strains appear to result from both genetic differences and environmental factors. Thirteen characters, extracted from stepwise discriminant analysis, played important roles in morphological differentiation. These characters were mainly measures related to body depth and head size.     

Taxonomic separation ofKengyilia (Poaceae: Triticeae) in relation to nearest relatedRoegneria,Elymus, andAgropyron,based on some morphological characters

Based on 100 species representative of the four genera, we scored 290 herbarium specimens for a number of morphological characters. The data were subjected to canonical discriminant analysis using characters different from those in the identification key to these genera byBaum, Yen, andYang (1991). These characters collectively support the four groupsAgropyron, Kengyilia, Roegneria, andElymus as previously defined. The four groups are also supported by the linear discriminant function with an overall rate of 83% correct classification. Length of lemma awn was found to be an additional diagnostic character asAgropyron andKengyilia have lemma awns shorter than 5 mm, whereasRoegneria andElymus have longer lemma awns with very few exceptions. Length of glume awns is also a useful supplementary generic diagnostic.Agropyron andElymus have glume awns, whereas the majority of species ofKengyilia and more than half of the species ofRoegneria lack them. If a glume awn is present it is usually not longer than 1 mm.