Dupontia (Poaceae) in North America

2003 ◽  
Vol 81 (8) ◽  
pp. 769-779 ◽  
Author(s):  
A K Brysting ◽  
S G Aiken ◽  
L P Lefkovitch ◽  
R L Boles
Keyword(s):  
Chromosome Numbers ◽  
Morphological Characteristics ◽  
Field Work ◽  
Distinct Species ◽  
Plant Size ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Ploidy Levels ◽  
Random Variability ◽  
Conditional Clustering

Challenged by work on the Panarctic Flora project and apparent discrepancies in recent taxonomic treatments, the genus Dupontia was studied from herbarium specimens, including types and chromosome vouchers, and by numerical taxonomy, mapping the distribution of morphological characteristics, consideration of chromosome numbers, and field work in the Canadian Arctic. Our results using these techniques show random variability in many characters and differences in plant size that appear to be partly habitat related. The treatment of the genus has varied from the recognition of one variable species to three or more distinct species. Morphological characters, used in the literature to divide the genus Dupontia into more than one taxon, cannot be reliably applied to distinguish most North American plants. Continuous morphological variation in combination with high and variable ploidy levels, effective vegetative growth, and rare sexual reproduction suggests the use of a broad species concept. Until further evidence is available, our results support treating the genus as monotypic.Key words: Poaceae, Dupontia, morphology, chromosome numbers, conditional clustering, contingency tables.

scholarly journals Some additional data to the genus Bombax L. (Malvaceae- Bombacoideae) for the flora of Vietnam

2017 ◽  
Vol 33 (4) ◽  
Author(s):  
Phan Ke Loc ◽  
Nguyen Thi Nhung ◽  
Nguyen Thi Anh Duyen
Keyword(s):  
Species Composition ◽  
Additional Data ◽  
Morphological Characteristics ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
National University ◽  
Cultivated Species ◽  
Species Composition And Distribution ◽  
First Time ◽  
Small Genus

Some additional data to the genus Bombax L. (Malvaceae- Bombacoideae) for the flora of Vietnam   Phan Kế Lộc1, Nguyễn Thị Nhung2, Nguyễn Thị Ánh Duyên3 1Faculty of Biology, VNU University of Science, 334 Nguyễn Trãi, Thanh Xuân, Hanoi, Vietnam 2VNU University of Education, 144 Xuân Thủy, Cầu Giấy, Hanoi, Vietnam   Abstract: Bombax L. (Malvaceae- Bombacoideae) is a small genus with 8 species, distributed in Old World. Up to now there are 4 species of Bombax registered for the flora of Vietnam, namely B. albidum Gagnep., B. anceps Pierre, B. ceiba L. and B. insigne Wall. Goal of this paper is to contribute some additional data of its species composition and distribution. Specimens of six collecting numbers (three of native and three of cultivated species) were collected, studied and housed at the herbarium (HNU) of the Hanoi University of Science, Vietnam National University. Due to the lacking of branchlets bearing leaves and flowers of collected specimen P 7660 is named as Bombax cf. cambodiense Pierre, new occurrence for the flora. Bombax anceps Pierre for the first time was seen and taken photos in northwestern Son La Province, far from the main locations in the south. Morphological characters mainly of abaxial face calyx, petals, stamens and pistil of cultivated Bombax ceiba L. are illustrated. The occurrence of Bombax insigne Wall. is not confirmed by herbarium specimens. Comparaison of main morphological characteristics of studied Bombax taxa are presented.

A Systematic Analysis of the Brushtail Possum, Trichosurus-Vulpecula (Kerr, 1792) (Marsupialia, Phalangeridae)

1991 ◽  
Vol 39 (3) ◽  
pp. 313 ◽  
Author(s):  
JA Kerle ◽  
GM Mckay ◽  
GB Sharman
Keyword(s):  
Morphological Characteristics ◽  
Taxonomic Status ◽  
Single Species ◽  
Distinct Species ◽  
Morphological Characters ◽  
Brushtail Possum ◽  
Trichosurus Vulpecula ◽  
Ecological Data ◽  
Systematic Analysis ◽  
North Eastern

The taxonomic status of distinctive populations of the widespread and morphologically variable possum Trichosurus vulpecula was examined. For the analysis, morphological characters (body size, fur colour and skull dimensions), karyotypes, electrophoretic allozyme, and ecological data were compared for as many Trichosurus populations as possible. There are insufficient differences between populations of T. vulpecula to reject a null hypothesis that they comprise a single species. Tasmanian, northern and south-western Australian populations could be retained as subspecies, but insufficient data exist to resolve the specific status of Atheton Tabeland and north-eastern Australian populations. One enigmatic result is that the skull morphometrics and allozymes of T. caninus were not distinguishable from those of sympatric T. vulpecula. However, other morphological characteristics and ecological data provide adequate evidence the T. caninus is a distinct species.

A practical treatment of the Solidago gigantea complex

1984 ◽  
Vol 62 (6) ◽  
pp. 1279-1282 ◽  
Author(s):  
Gary H. Morton
Keyword(s):  
Ploidy Level ◽  
Chromosome Numbers ◽  
Single Species ◽  
Morphological Characters ◽  
Geographic Range ◽  
Chromosome Counts ◽  
Separate Species ◽  
Ploidy Levels ◽  
Solidago Gigantea ◽  
Infraspecific Taxa

The Solidago gigantea complex is usually treated in floristic works as being composed of a single species with two infraspecific taxa: var. gigantea and var. serotina. Recent studies by Beaudry revealed that the complex is composed of individuals of three different chromosome numbers. He proposed that the individuals at each ploidy level be treated as belonging to separate species: S. gigantea, 2n = 18; S. serotina, 2n = 36; and S. shinnersii, 2n = 54. Chromosome counts reported in this paper of individuals of the S. gigantea complex from a wide geographic range verify the existence of the three different ploidy levels. Evaluation of the morphological characters of these vouchers, however, shows that plants with different chromosome numbers cannot be consistently separated using morphological characters. It is proposed, therefore, that the complex be treated as a single species without any infraspecific categories.

A contribution to the taxonomy of the Carex macloviana aggregate (Cyperaceae) in western Canada and Alaska

1984 ◽  
Vol 62 (8) ◽  
pp. 1592-1607 ◽  
Author(s):  
Richard Whitkus ◽  
John G. Packer
Keyword(s):  
Chromosome Numbers ◽  
Distinct Species ◽  
Geographic Range ◽  
Numerical Analyses ◽  
Herbarium Specimens ◽  
Western Canada ◽  
Extreme Form ◽  
Ecological Preferences ◽  
Phenetic Relationships ◽  
Morphological Differences

The Carex macloviana aggregate consists of several phenetically similar taxa in western Canada and Alaska. Small morphological differences among the taxa have led to treatments recognizing either one more inclusive or six less inclusive species. A detailed morphotaxonomic investigation was initiated to delimit species and describe phenetic relationships among them. Results from study of herbarium specimens from the entire geographic range of each taxon and various numerical analyses of Canadian and Alaskan material indicate the taxa C. microptera Mack., C. festivella Mack., and C. limnophila Hermann comprise one species; C. haydeniana Olney is another species, phenetically similar to the first, and C. macloviana D'Urv. and C. pachystachya Cham. ex Steud. are two similar but distinct species. The species were also determined to have different chromosome numbers, geographic distributions, and ecological preferences. A previously unrecognized group of specimens, designated "stubby," was recognized and included in all the analyses to determine its phenetic position within the aggregate. It is concluded that "stubby" represents an extreme form of the variable C. pachystachya.

ÉTUDES SUR LE GENRE SOLIDAGO L. : II. LA MISE EN ÉVIDENCE DE LA POLYPLOÏDIE ENDOTAXONIQUE CHEZ S. PURSHII PORTER ET LES TAXA SIMILAIRES

1958 ◽  
Vol 36 (5) ◽  
pp. 663-670 ◽  
Author(s):  
Jean R. Beaudry ◽  
Alexis Zinger ◽  
Jacques Saint-Pierre
Keyword(s):  
Chromosome Number ◽  
Geographical Distribution ◽  
Chromosome Numbers ◽  
Guard Cells ◽  
Morphological Characters ◽  
The Other ◽  
Herbarium Specimens ◽  
Positive Correlation ◽  
Rapid Technique

In Solidago Purshii Porter, there are two cytodemes, one diploid (2n = 18) and the other tetraploid (2n = 36), which can be distinguished on the basis of the length of the guard cells of their leaf stomata. The diploid plants possess guard cells which are smaller than those of the tetraploid. These two entities of S. Purshii thus belong to the groups of cytodemes in which there exists a positive correlation between the chromosome numbers and the dimensions of certain quantitative morphological characters, such as the length of the guard cells.In groups in which the variation curves of the characters of the different cytodemes overlap little or not, the geographical distribution of the different cytodemes of the complex may be studied much more easily, rapidly, and comprehensively by measuring the length of the guard cells of herbarium specimens than by making chromosome number determinations. The data presented indicate that when sampling is made under the conditions described in this paper, determinations of the length of two guard cells of stomata of one mid-leaf per individual, made on two individuals per colony, is satisfactory for that purpose, on the average. However, it is recommended, as a safeguard, to increase these figures by a few units, and to make always a few direct chromosome number determinations to check the accuracy of this rapid technique. These direct determinations may also be necessary to know the chromosome numbers of certain extreme individuals of the different cytodemes which have guard cells that differ little in length.

Chromosome and morphological studies in the Mimosa debilis complex (Mimosoideae, Leguminosae) from southern South America

2010 ◽  
Vol 58 (1) ◽  
pp. 12 ◽  
Author(s):  
Matías Morales ◽  
Arturo F. Wulff ◽  
Renée H. Fortunato ◽  
Lidia Poggio
Keyword(s):  
Chromosome Numbers ◽  
Floral Morphology ◽  
Morphological Characters ◽  
Present Contribution ◽  
Ploidy Levels ◽  
Morphological Studies ◽  
Hybrid Swarms ◽  
Different Populations ◽  
First Time ◽  
Different Origin

Mimosa debilis Humb. & Bonpl. ex Willd. and M. nuda Benth. were grouped in specific and infraspecific complexes. Both taxa showed exomorphological similarities, with conflicts in their taxonomic circumscription and present different ploidy levels. The objective of the present contribution was to analyse chromosome numbers of different populations and to evaluate morphological characters of specimens from Paraguay, Argentina and boundary regions. Chromosome numbers of M. debilis var. debilis (2n = 2x = 26 and 2n = 4x = 52) confirmed previous reports, whereas those of M. nuda var. glaberrima (2x = 26, 4x = 52), M. nuda var. gracilipes (2x = 26, 4x = 52) and M. nuda var. nuda (4x = 52) are presented for the first time. Variation was observed in habit, foliar and floral morphology and was correlated with the chromosome number and the geographical distribution of the taxa. Groups with stable morphological characters and restricted geographic distribution were identified. Also, the results showed a pattern of hybrid swarms and polyploids of different origin that may explain the existence of taxonomic conflicts in the M. debilis–M. nuda species complex. On the basis of these results, M. nuda should be included in the synonymy of M. debilis.

Phylogenetic Analysis and Taxonomic Delimitation of the “Hairy-Fig” Complex of Ficus sect. Eriosycea (Moraceae) in China

Phytotaxa ◽  
2016 ◽  
Vol 261 (2) ◽  
pp. 121 ◽  
Author(s):  
JING LU ◽  
PING GUI ◽  
ZHONG-LING LU ◽  
LI-FANG ZHANG ◽  
HUAI-ZHEN TIAN ◽  
...  
Keyword(s):  
Cluster Analysis ◽  
Phylogenetic Analysis ◽  
Genetic Background ◽  
Phylogenetic Trees ◽  
Morphological Characteristics ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Microsatellite Primers ◽  
The Status ◽  
Similar Genetic Background

The hairy-fig complex of Ficus sect. Eriosycea (Moraceae) includes F. hirta, F. esquiroliana, F. simplicissima and a Chinese entity misidentified as F. fulva. These species are difficult to delimit because of the continuously varying morphological characteristics. In order to re-evaluate the status of these taxa, herbarium specimens were extensively examined and 118 samples of the complex were selected for anatomical and molecular analysis. ITS, ETS and trnH-psbA were applied for constructing phylogenetic trees and fluorescently labeled microsatellite primers were screened for cluster analysis. The results showed that all the four species show continuously variable morphological characters and make up one well supported clade on the phylogenetic trees, and that this similar genetic background was confirmed by the cluster analysis. In conclusion, all the four taxa of the hairy-fig complex recorded in China should be combined as one species F. simplicissima, with two varieties: var. simplicissima and var. roxburghii (Miquel) Hong-Qing Li & Jing Lu.

NEW CHROMOSOME COUNTS AND NUCLEAR CHARACTERISTICS FOR SOME MEMBERS OF GESNERIACEAE SUBFAMILY CYRTANDROIDEAE FROM CHINA AND VIETNAM

2003 ◽  
Vol 60 (3) ◽  
pp. 449-466 ◽  
Author(s):  
P. ZHOU ◽  
Z.-J. GU ◽  
M. MÖLLER
Keyword(s):  
Chromosome Numbers ◽  
Morphological Characteristics ◽  
Morphological Characters ◽  
Chromosome Condensation ◽  
Chromosome Counts ◽  
Interphase Nuclei ◽  
Condensation Pattern ◽  
Gradient Type

The morphological characteristics of mitotic interphase, prophase and metaphase nuclei were analysed for 21 taxa in 14 genera from three different tribes of subfamily Cyrtandroideae (Gesneriaceae) from Asia. Interphase nuclei were classified into three categories: (1) complex chromocentres, as in Ancylostemon, Briggsia, Briggsiopsis, Chirita, Loxostigma, Lysionotus, Oreocharis, Petrocosmea, Raphiocarpus and Whytockia, (2) simple chromocentres, as in Paraboea and Rhabdothamnopsis, and (3) round prochromosomes, as in Anna and Didymocarpus. Species with complex chromocentres seem to be most common among all three tribes. The data further indicate that tribe Didymocarpeae is cytologically much more heterogeneous than other tribes, which accords with the diversity in morphological characters. Three types of chromosome condensation pattern during mitotic prophase were observed, here described as interstitial, gradient and proximal. Except for Ancylostemon, exhibiting a proximal type, and Lysionotus and Whytockia possessing a gradient type, all other species analysed to date exhibit the interstitial type. Our study also reports the chromosome numbers of 12 species in 10 genera of subfamily Cyrtandroideae from China and Vietnam; 11 of these counts are new.

The separation of Eleocharis obtusa and Eleocharis ovata (Cyperaceae) in eastern Canada

1996 ◽  
Vol 74 (2) ◽  
pp. 238-242 ◽  
Author(s):  
B. M. H. Larson ◽  
P. M. Catling
Keyword(s):  
Distinct Species ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Eastern Canada ◽  
Stamen Number ◽  
Morphological Relationship

Eleocharis obtusa and Eleocharis ovata are recognized as distinct species or combined in recent taxonomic literature. To assess their morphological relationship and to evaluate all morphological characters potentially useful for their separation, 11 floral and achene characters were measured on 130 eastern Canadian herbarium specimens. Tubercle width was bimodally distributed and completely separated groups established on the basis of stamen number: plants referable to E. ovata had tubercles less than 0.5 mm wide and two stamens, whereas plants referable to E. obtusa had tubercles greater than 0.5 mm wide and three stamens. Since determination of stamen number requires dissection under a microscope and tubercle width requires accurate measurement, the most readily utilized character was found to be the ratio of tubercle width to achene width, which can be measured or estimated. The tubercle was less than 2/3 the width of the achene in E. ovata and more than 2/3 in E. obtusa. Differences in these characters were associated with significant but less dramatic differences in other characters, suggesting that the two taxa should be treated as distinct species. Keywords: Eleocharis obtusa, Eleocharis ovata, Cyperaceae, taxonomy, classification, Canada.

Inheritance of Some Morphological Characteristics of Parental Lines in Mustard-Rape Hybrid

2020 ◽  
pp. 23-30
Keyword(s):  
First Generation ◽  
Agronomic Traits ◽  
Morphological Characteristics ◽  
Morphological Characters ◽  
Hybrid Plant ◽  
Distant Hybridization ◽  
Degree Of Dominance ◽  
Whole Plant ◽  
Row Width ◽  
The Difference

Distant hybridization is known to play an important role in expanding the gene pool of any crop. It is believed that the combination of different genomes in one nucleus, as a rule, is accompanied by the phenomenon of “genomic shock”, resulting in a variety of genetic and epigenetic changes. This provides a wealth of material for the selection of genotypes adapted to different environmental conditions. Interspecific hybrids in different combinations were obtained in the genus Brassica, however, until now, interest in distant hybridization in this genus has not died out, since such important crops as rapeseed and mustard demand an improvement of many important agronomic traits. The aim of this work was to study the degree of manifestation of morphological characters of a leaf, flower, and plant as a whole in the hybrid obtained by crossing of brown mustard of the variety Slavyanka and a collection specimen of spring rape. Seeds were sown in the spring of 2019 in a field with 30 cm row width. During the flowering period a number of morphological characters of a flower, leaf, and the whole plant were analyzed. Each parameter was evaluated with 10 plants. The degree of dominance in first-generation hybrid was calculated by the formula of Beil, Atkins (1965). The dominance coefficients were not determined in the case when the difference between the parental samples was insignificant. Differences between parental samples were determined by Student t-test. The level of heterosis was calculated according to the formula of Rasul et al (2002). In a mustard-rapeseed hybrid, the size of the leaves of the lower row was inherited by the type of rapeseed, which had larger leaves than mustard. The height of the hybrid plant was inherited by the type of mustard (hp = 1.32, Ht = 4.89%), and intermediate inheritance was observed for the length of the internodes (hp = -0.48). The size of the flower petals and sepals was inherited by the type of rapeseed, and significant heterosis was observed for the length of the pistil (Ht = 33.57%). The data obtained are of interest for understanding the interaction of genes of different genomes in the genus Brassica.

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