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1.
该文报道了采自新疆的木灵藓属中国2个新记录种——帕米尔木灵藓(Orthotrichum pamiricum)和细齿木灵藓(O.scanicum)。帕米尔木灵藓的识别特征为:叶尖钝,气孔隐型,多着生于孢蒴下部,外齿层齿片8对,干燥时蒴齿背曲,内齿层蒴条16,上部内曲;细齿木灵藓的识别特征为:叶尖部具细齿,气孔半隐型,蒴帽具分散的透明毛,内齿层和外齿层均16片,具8条黄色细沟,干燥时中部以上具沟。对这2种藓类的形态特征、生境和地理分布及与其相似种的形态学进行了比较分析,并绘制了每种的形态结构墨线图。木灵藓属植物在中国的新分布记录进一步表明,新疆地区富含生物多样性,并与中亚植物区系存在密切关系。 相似文献
2.
Martin V. Sørensen Iben Heiner Ole Ziemer Birger Neuhaus 《Helgoland Marine Research》2007,61(4):247-265
One new kinorhynch genus and species and one new species from the genus Zelinkaderes are described from sandy sediment off Fort Pierce, Florida. The new genus and species, Tubulideres seminoli gen. et sp. nov. is characterized by the presence of the first trunk segment consisting of a closed ring, the second segment
of a bent tergal plate with a midventral articulation and the following nine segments consisting of a tergal and two sternal
plates. Cuspidate spines are not present, but flexible tubules are located on several segments, and in particular concentrated
on the ventral side of the second segment. Middorsal spines are present on all trunk segments and are alternatingly offset
to a position slightly lateral to the middorsal line. Zelinkaderes brightae nov. sp. is characterized by its spine formula in having middorsal spines on trunk segments 4, 6 and 8–11, lateroventral
acicular spines on segment 2, lateral accessory cuspidate spines on segments 2 and 8, ventrolateral cuspidate spines on segments
4–6 and 9, lateroventral acicular spines present on segments 8 and 9, and midterminal, lateral terminal and lateral terminal
accessory spines on segment 11. The spine formula of Z. brightae nov. sp. places it in a position in between Z. submersus and a clade consisting of Z. klepali and Z. floridensis. The new findings on Z. brightae nov. sp. have led us to propose an emended diagnosis for the genus. 相似文献
3.
The genus Diacyclops Kiefer, 1927 emend. Morton (1985) includes more than 100 species, widely distributed in all kinds of freshwater environments, and is the richest genus in the family Cyclopidae. Traditionally, Diacyclops species were defined according to differences in a few morphological characters; some characters (number of antennulary segments, segmentation pattern of swimming legs) are useful only in the separation of species groups, others (length of caudal rami and caudal setae) are highly variable even within the same population. During the study of the D. languidoides-group, minute morphological characters were used to differentiate between species (spinulation pattern and setation of antennary basis, setation and aesthetasc shape of male antennule, setation of mandibulary palp and maxilliped, shape of leg 4 basis) which allow to identify several valid species up to now concealed under the name `Diacyclops languidoides' (Lilljeborg, 1901). The coexistence of up to six congeneric species in the same sampling area: (a) supports the validity of the proposed taxonomic characters, (b) demonstrates that species richness may be highly underestimated in freshwater cyclopoid assemblages in absence of good taxonomic practice; and (c) requires an ecological explanation of species coexistence. The role of morphologically based taxonomy in order to solve general problems of distributional ecology and theoretical biology is explored. 相似文献
4.
Bruce A. Ford Julian R. Starr D. A. Ross McQueen Robert F. C. Naczi 《Plant Systematics and Evolution》1998,212(1-2):31-51
Allozyme variation was examined inCarex sect.Phyllostachys (Cyperaceae) to provide insight into phylogenetic relationships hypothesized in an earlier study and to determine the degree of genetic differentiation within and between taxa. Genetic identity values are concordant with the morphological differences found between species. The lowest values are found between species with the greatest morphological dissimilarity. Conversely, the highest values are associated with species pairs distinguished by relatively few morphological differences. Conspecific populations possess high genetic identities, although interpopulation differentiation has characterized the evolutionary history of some species. Geographic patterning is also evident within species, with geographically proximate populations often having the highest identity values. Phylogenetic trees produced using different cladistic methods were poorly supported and varied in their depiction of relationships among species. One cladogram produced using presence/absence allelic data is more or less congruent with a topology recovered from an earlier analysis utilizing molecular and morphological data. The wide- and narrow-scaled clades are maintained as are the sister species pairsC. backii/C. saximontana, C. basiantha/C. superata, andC. jamesii/C. juniperorum. Contrary to the finding of our previous study, however,C. willdenowii is aligned withC. jamesii/C. juniperorum. 相似文献
5.
Batrachospermum arcuatum specimens were analysed from seven stream segments in North China. Morphological characteristics were observed and cluster analysis was used to evaluate the divergence among thalli from. Sequence data of the rbcL gene (chloroplast gene) and cox2-3 spacer region (mitochondrial gene) were also utilized to evaluate genetic variation in specimens among stream segments. The specimens from four of the streams were monoecious, while the individuals at the other three locations were dioecious. Cluster analysis showed that the monoecious specimens were not separated from the dioecious specimens, based on morphology, but rather the specimens were grouped by geographical closeness and habitat similarity. Likewise, the combined analyses of rbcL and the cox2-3 spacer data from provided more evidence that breeding system (monoecy vs. dioecy) is not a good morphological character to distinguish species. 相似文献
6.
Annemarie Neuner Holger W. Jannasch Shimshon Belkin Karl. O. Stetter 《Archives of microbiology》1990,153(2):205-207
We describe a new species, Thermococcus litoralis, which is different from the type species Thermococcus celer in molecular, morphological and physiological characteristics.Abbreviations 3 x SSC
(standard saline citrate)
- 0.45 M NaCl
0.045 M Na3-citrate 相似文献
7.
Holzer AS Montero FE Repullés A Nolan MJ Sitja-Bobadilla A Alvarez-Pellitero P Zarza C Raga JA 《Parasitology international》2008,57(4):472-482
A new sanguinicolid trematode, Cardicola aurata sp. n., is described from gilthead seabream Sparus aurata L., from off the Spanish Mediterranean coast. The morphology of C. aurata sp. n. generally agrees with the diagnosis of the genus, however, in contrast to all other reported Cardicola spp. the male pore is located sub-medially at the posterior end of the body instead of sinistrally before the posterior end of the body. Based on a comparison of the morphology as well as partial 28S and ITS2 rDNA sequence data from the present species with that from closely related species, it was decided to emend the diagnosis of Cardicola rather than create a new genus, as the aberrant position of the male pore is likely to be an autapomorphy. The phylogenetic analyses revealed a close relationship between Cardicola and Paradeontacylix, two genera with considerable morphological differences; C. aurata sp. n. occupies a position intermediate to these genera. Thus, a morphological comparison of Cardicola, Paradeontacylix and Braya, a genus which is morphologically similar to Cardicola but clusters basal to the Cardicola/Paradeontacylix clade, was conducted. The results of this comparison showed that despite large differences with regard to body shape, the organisation of the internal organs is very similar in species of Cardicola and Paradeontacylix. The synopsis of morphological data and molecular phylogeny allows for interpretations regarding the importance of different morphological features for the phylogenetic inference of the Sanguinicolidae. 相似文献
8.
Robert Ornduff 《Plant Systematics and Evolution》1988,159(1-2):81-83
The Western Australian annual of restricted distribution,Villarsia congestiflora, has distylous flowers and pollen-size heteromorphism. Results of a crossing program indicate that this species is strongly self-incompatible, that crosses among individuals of the same morph produce little or no seed, and that intermorph crosses produce copious seed. The species shares a number of morphological and ecological traits withV. capitata, another distylous, self-incompatible annual species of Western Australia with a greater area of distribution. Artificial hybrids between the two, however, showed reduced pollen stainability. Both species combine a number of specialized morphological features with a breeding system that is primitive for the familyMenyanthaceae. 相似文献
9.
10.
The inter- and intraspecific variability of Cichorium intybus L. was examined to evaluate potential morphological and molecular diagnostic character states. Two diagnostic and one overlapping morphological character clearly delimit the two species C. intybus and C. spinosum. All applied molecular methods (ITS, AFLP, Microsatellites) failed to significantly discriminate between these accepted species. As the morphological traits are fixed and heritable, criteria for species delimitation are fulfilled. These traits, however, are apparently due to mutations of a few crucial loci affecting the morphological diagnostic character states. Intraspecific variability within C. intybus revealed to be highly influenced by plastic response to local environmental factors and subspecific delimitation cannot be supported. 相似文献
11.
D. J. Padgett 《Plant Systematics and Evolution》2003,239(3-4):187-197
Previous taxonomic assessments of the hydrophytic genus Nuphar Sm. (Nymphaeaceae) have inadequately considered the range of morphological variation existing in the genus. A comprehensive statistical analysis of morphological features among the recognized taxa of Nuphar is presented here, first using 10 fruit characters to delimit the separation of two infrageneric groups of taxa, and secondly using 31 characters to quantify the morphological variation found within sect. Nuphar. Results from combined phenetic analyses provided empirical support for recognition of two infrageneric groups of species in the genus (largely by fruit, stigmatic disk margin, neck, and stigmatic disk size) and for separation of taxa within sect. Nuphar (by leaf size, and fruit disk and neck size). Statistical analyses demonstrate that extensive variation in ranges of character states exists among sect. Nuphar taxa. However, a suite of qualitative and quantitative characters can be used to recognize five species and three subspecies within this predominantly Old World assemblage. 相似文献
12.
该文报道了中国苦苣苔科(Gesneriaceae)一新记录属——四轮苣苔属(Tetraphyllum Griff. ex C. B. Clarke)。该新记录属,即四轮苣苔属仅有3种,其中密花四轮苣苔[T. confertiflorum(Drake)B. L. Burtt]在我国首次记录。该研究提供了该属的形态描述和分种区别特征,并提供了该种的详细形态描述及彩色照片。凭证标本馆藏于广西植物研究所标本馆(IBK)和上海辰山植物标本馆(CSH)。 相似文献
13.
Evolutionary relationships and infra- and interspecific variability within the species ofTulipa sect.Eriostemones
Boissier were studied. Measurements of 35 morphological characters were used for principal component and canonical variate analyses. Crossing experiments and chromosome counts were carried out. Two axes of morphological variation were encountered within the principal component plot. Variation of subsect.Biflores was traced along one axis, the species of subsect.Australes as well asSaxatiles were found along the other axis. The nomenclature of names of subsect.Biflores was considered on the basis of their geography, specific morphological characteristics and polyploidy. Conspecificity of names of all species was tested based on both morphology and crossability. 相似文献
14.
J. G. Chmielewski C. C. Chinnappa J. C. Semple 《Plant Systematics and Evolution》1990,169(3-4):123-150
Patterns of intraspecific variation were examined inAntennaria alborosea
A. E. Porsild,A. corymbosa
E. Nels,A. marginata
Greene,A. microphylla
Rydb.,A. parvifolia
Nutt., andA. umbrinella
Rydb. AlthoughA. alborosea was initially considered arctic in distribution, it became apparent that a southern montane element also exists. Our results suggest that morphological differences between arctic and southern montane specimens represent clinal variation. The additional morphological data for specimens that occur more than 1,500 km south of the species' range as it was initially described result in a better understanding of this once presumed arctic taxon. Morphological variation in the dioecious speciesA. corymbosa, A. marginata, A. microphylla, A. parvifolia, andA. umbrinella was greater between the genders than was geographic variation within each gender. These results demonstrate that both pistillate and staminate specimens must be examined in dioecious species ofAntennaria if morphological variation in the respective species is to be fully understood. Character size or number of broadly distributed species (A. microphylla andA. parvifolia) generally decreased with increasing longitude, whereas characters of species with more restricted distributions (A. alborosea, A. corymbosa, andA. marginata) generally increased in size or number with increasing latitude or longitude.Antennaria umbrinella was an exception in this respect. 相似文献
15.
Hordeum caespitosum
Scribner,H. jubatum L., andH. lechleri (Steudel)Schenck are very similar in appearance and therefore until recently were mostly not recognized as separate entities. The first two are tetraploid and natives to North America, but the second occurs naturally in eastern Siberia and has been introduced in Europe and South America and may become a cosmopolitan weed. The third is hexaploid and South American. This study analyses their morphological diversity by means of selected multivariate techniques in order to determine if there is justification to recognize them as three separate morphological species. Logistic discrimination, although based on a reduced set of characters, yielded the highest percent of correct assignments. A linear discriminant function is provided and validated by 100 bootstrap repeats. Canonical discriminant analysis indicated three groups. It is subsequently concluded that the three are separate morphological species. Although a linear discriminant function is given, a traditional identification key is provided based on the palea length and triad (the group of three spikelets at each rachis node) length. 相似文献
16.
Uromyces appendiculatus, inclusive of three varieties, is distinguished from U. vignae primarily by the position of urediniospore germ pores and putative host specificity. However, opinions concerning these morphological and physiological features as taxonomic characters have varied greatly, and distinction of these species has often been confused. To clarify the taxonomy of these two species, morphological features of urediniospores and teliospores of 225 rust fungus specimens on species of Phaseolus, Vigna, Apios, Lablab, and Dunbaria were examined by light microscopy and scanning electron microscopy. Forty-five specimens were subjected to molecular phylogenetic analyses. As a result, the position of germ pores in urediniospores and the teliospore-wall thickness were considered as good characters to separate three morphological groups. In molecular analyses, the specimens fell into two and three clades based on the nucleotide sequence at D1/D2 domain of LSU rDNA and ITS regions, respectively. One of the D1/D2 clades corresponded to one morphological group whereas another D1/D2 clade included two other morphological groups. In contrast, each of the three ITS clades corresponded to a separate morphological group. Neither morphological groups nor molecular clades were host limited. It is suggested that the three morphological groups that corresponded to three distinct ITS clades constitute distinct species.Contribution no. 186 from the Laboratory of Plant Parasitic Mycology, Institute of Agriculture and Forestry, University of Tsukuba, Japan 相似文献
17.
L. sativa L. cultivars were compared morphologically with accessions ofL. saligna L.,L. serriola L., andL. virosa L. in order to define the infra- and interspecific variation. Multivariate analysis (principal component analysis) distinguished four groups corresponding with the four species. Infraspecific variation (e.g., colour, leaf shape) withinL. sativa is the largest, because breeding has caused a large variation in vegetative features; infraspecific variation withinL. serriola is also large. Three plants of one accession were placed betweenL. sativa andL. serriola because they showed morphological characteristics of both species. They are still classified asL. sativa. The morphological differences betweenL. sativa andL. serriola are too large to consider these two as one species. The descent of the cultivar groups and the four species is described. 相似文献
18.
对中国杜鹃花科特有种:臭越橘(Vaccinium foetidissimum H. Lév. & Vaniot)的花部形态特征进行了描述。基于新补充的花部特征,讨论了该种与其相似种的区别。 相似文献
19.
The tropical Indo-Pacific genus Excoecaria L. (Euphorbiaceae) has several closely related species in Australia whose taxonomic relationships are unclear. The most widely reported species in Australia is the mangrove species Excoecaria agallocha L. (type species), whose taxonomic and geographic limits are difficult to define from its closely related species or sub-species. Two additional taxa have also been described but not clearly differentiated from the type species: Excoecaria dallachyana Baillon and Excoecaria ovalis Endl. This project aimed to determine the taxonomic relationships of the Australian Excoecaria species using both leaf morphological data and DNA sequence data from the internal transcribed spacer (ITS) region of ribosomal genes. The nucleotide differences in the examined ITS1 region show that E. agallocha from eastern Australia and E. ovalis from Western Australia respectively, are genetically uniform within species but differ from each other consistently, thus supporting species status. The leaf morphological data also support this view: single factor analysis of variance consistently separated E. ovalis from E. agallocha on the basis of leaf width, leaf length and length of petiole. In contrast, E. ovalis from the Gulf of Carpentaria differs only slightly from E. ovalis in Western Australia, but no evidence was found to suggest any leaf morphological differentiation within this species. The analysis also suggests that E. dallachyana is not closely related to either mangrove species E. agallocha or E. ovalis, despite superficial morphological similarities. 相似文献
20.
A new species, Crocus demirizianus O. Erol & L. Can is described and illustrated from northwestern Turkey. Crocus demirizianus was found in the Çanakkale province, near the district of Çan, and is undoubtedly related to the Crocus biflorus complex. However, the species differs from its relatives by typically sagittate anthers, and flowers without prominent stripes on outer segments. Diagnostic morphological characters are discussed and high resolution images are presented. 相似文献