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 cytotaxonomic survey of the Pteridophyta of Australia

2002 ◽  
Vol 15 (6) ◽  
pp. 839 ◽  
Author(s):  
Mary D. Tindale ◽  
S. K. Roy
Keyword(s):  
Ploidy Level ◽  
New Combination ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Australian Species ◽  
Number Of Species ◽  
Lord Howe Island ◽  
Species Complexes ◽  
Living Material ◽  
First Time

A cytotaxonomic survey of the ferns and fern allies of Australia (including Lord Howe Island) is presented. Five-hundred-and-twenty-six chromosome counts of 268 Australian species, subspecies, varieties, variants and hybrids are recorded, only a small number having been previously investigated by other botanists on Australian material. Diploids represent c. 62% of the counts on species and c. 38% on polyploids, the latter ranging principally from triploids to a single decaploid and dodecaploid (but no heptaploids). More than one ploidy level has been reported in 19 taxa (almost 8% of taxa). Counts of 10x for Asplenium aethiopicum and 12x for A.�flabellifolium are the highest definite ploidy levels for the Australian pteridophyte flora. Chromosome counts for 29 families and 89 genera are cited. Only diploids were reported for Osmundaceae and Cyatheaceae, but only polyploids for the Psilotaceae, Vittariaceae and Ophioglossaceae. An analysis is given of the levels of ploidy in 248 taxa, excluding the Lycopodiaceae and Hymenophyllaceae. The percentages of diploids and polyploids in Australian species are compared with those of nearby countries. Many species reported on here have never been cytologically investigated before, while others have not been studied previously on Australian material. The following genera have been examined cytologically for the first time: Coveniella Tindale, n = 41; Paraceterach (F.Muell.) Copel., n = 29; 'Oenotrichia Copel.', 2n = 82 (2x); Revwattsia (Watts) D.L.Jones, 2n = c. 328 (8x); and Pteridoblechnum Hennipman (2n = 54). The phylogeny of the genera is discussed in the light of these findings. Certain families such as the Adiantaceae, Cyatheaceae, Hymenophyllaceae, Lindsaeaceae and Marsileaceae were given special attention by collecting as much living material as possible. A number of species-complexes has been found and further chromosome counts added to intercontinental species complexes. The Döpp-Manton and Braithwaite forms of reproductive apomixis have been reported amongst some genera. Endemism, hybridity and apogamy amongst Australian pteridophytes are discussed, as well as homosporous and heterosporous species. The new combination Phymatosorus membranifolius (R.Br.) Tindale is made.

scholarly journals Chromosome Number, Ploidy Level, and Nuclear DNA Content in 23 Species of Echeveria (Crassulaceae)

Genes ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1950
Author(s):  
Guadalupe Palomino ◽  
Javier Martínez-Ramón ◽  
Verónica Cepeda-Cornejo ◽  
Miriam Ladd-Otero ◽  
Patricia Romero ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Chromosome Number ◽  
Ploidy Level ◽  
Dna Content ◽  
Chromosome Numbers ◽  
Nuclear Dna ◽  
Nuclear Dna Content ◽  
Root Tips ◽  
Ploidy Levels ◽  
Dna Amounts

Echeveria is a polyploid genus with a wide diversity of species and morphologies. The number of species registered for Echeveria is approximately 170; many of them are native to Mexico. This genus is of special interest in cytogenetic research because it has a variety of chromosome numbers and ploidy levels. Additionally, there are no studies concerning nuclear DNA content and the extent of endopolyploidy. This work aims to investigate the cytogenetic characteristics of 23 species of Echeveria collected in 9 states of Mexico, analyzing 2n chromosome numbers, ploidy level, nuclear DNA content, and endopolyploidy levels. Chromosome numbers were obtained from root tips. DNA content was obtained from the leaf parenchyma, which was processed according to the two-step protocol with Otto solutions and propidium iodide as fluorochrome, and then analyzed by flow cytometry. From the 23 species of Echeveria analyzed, 16 species lacked previous reports of 2n chromosome numbers. The 2n chromosome numbers found and analyzed in this research for Echeveria species ranged from 24 to 270. The range of 2C nuclear DNA amounts ranged from 1.26 pg in E. catorce to 7.70 pg in E. roseiflora, while the 1C values were 616 Mbp and 753 Mbp, respectively, for the same species. However, differences in the level of endopolyploidy nuclei were found, corresponding to 4 endocycles (8C, 16C, 32C and 64C) in E. olivacea, E. catorce, E. juarezensis and E. perezcalixii. In contrast, E. longiflora presented 3 endocycles (8C, 16C and 32C) and E. roseiflora presented 2 endocycles (8C and 16C). It has been suggested that polyploidization and diploidization processes, together with the presence of endopolyploidy, allowed Echeveria species to adapt and colonize new adverse environments.

scholarly journals The taxonomic status of Tilia dasystyla in Crimea, Ukraine

1999 ◽  
Vol 56 (2) ◽  
pp. 161-173 ◽  
Author(s):  
C. D. Pigott ◽  
B. Francis
Keyword(s):  
Logistic Regression ◽  
Principal Components ◽  
Taxonomic Status ◽  
Single Species ◽  
Morphological Characters ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
The Caucasus ◽  
Fresh Material ◽  
Components Analysis

Nine populations of Tilia dasystyla Steven (Tiliaceae) in the Crimean mountains (Krymskiye Gory), including the type locality at Kastel Dag, were studied in the field and sampled by collection of herbarium specimens. This material was compared with specimens referred to Tilia hegonifolia Steven collected in Crimea, the Caucasus and Iran. Measurements or scores of 21 morphological characters made on the dried material were analysed by principal components analysis and logistic regression. These analyses demonstrated that the majority of trees could be correctly allocated to either Crimea or the Caucasus and Iran on the basis of the shape of their leaves and the area of their bracts. In addition there are differences of leaf and bract texture and bract colour which can be observed in fresh material. Chromosome counts showed that Crimean trees and one Caucasian tree are tetraploid (2n = 164). It is proposed that the Crimean, Caucasian and Iranian trees be treated as a single species with at least two subspecies: Tilia dasystyla Steven subsp. dasystyla from Crimea and T. dasystyla Steven subsp. caucasica (V. Engl.) Pigott from the Caucasus and Iran.

scholarly journals Improved Method of Enzyme Digestion for Root Tip Cytology

HortScience ◽  
2017 ◽  
Vol 52 (7) ◽  
pp. 1029-1032 ◽  
Author(s):  
Jason D. Lattier ◽  
Hsuan Chen ◽  
Ryan N. Contreras
Keyword(s):  
Chromosome Numbers ◽  
Enzyme Digestion ◽  
Root Tip ◽  
Root Tips ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Long Duration ◽  
Wide Range ◽  
Plant Sciences ◽  
Breeding And Genetics

Chromosome numbers are an important botanical character for multiple fields of plant sciences, from plant breeding and genetics to systematics and taxonomy. Accurate chromosome counts in root tips of woody plants are often limited by their small, friable roots with numerous, small chromosomes. Current hydrolysis and enzyme digestion techniques require handling of roots before the root squash. However, optimum chromosome spread occurs when the cell walls have degraded past the point of easy handling. Here, we present a new enzyme digestion protocol that is fast, efficient, and flexible. This protocol reduces handling of the roots allowing for long-duration enzyme digestion. Digestions are performed on a microscope slide, eliminating the need for handling digested cells with forceps or pipettes. To illustrate the flexibility of this method across woody plant taxa, we performed chromosome counts on five angiosperms and one gymnosperm. Ploidy levels included diploids, triploids, and tetraploids with chromosome numbers ranging from 2n = 16 to 2n = 80. The range of holoploid 2C genome sizes spanned 1.54–24.71 pg. This protocol will provide a useful technique for plant cytologists working with taxa that exhibit a wide range of genome size and ploidy levels.

A taxonomic study of the large-glumed species of Stipa (Gramineae) occurring in Canada

1978 ◽  
Vol 56 (6) ◽  
pp. 606-625 ◽  
Author(s):  
Mary E. Barkworth
Keyword(s):  
Numerical Analysis ◽  
Cross Sections ◽  
Morphological Characters ◽  
Leaf Margin ◽  
Taxonomic Study ◽  
Separate Species ◽  
Distribution Maps ◽  
Quantitative Characters ◽  
Infraspecific Taxa ◽  
Stipa Comata

The morphology and awn anatomy of the large-glumed species of Stipa occurring in Canada were examined. Numerical analysis of the data indicates that S. spartea var. spartea and S. spartea var. curtiseta are very distinct taxa differing not only in many of their quantitative characters but also in nodal pubescence, ligule shape, and pubescence of the leaf margin. It is proposed that they be treated as separate species, S. spartea and S. curtiseta. Some evidence was found for differentiation within S. spartea s.s. but it was deemed insufficient for the recognition of infraspecific taxa. Stipa comata var. comata and S. comata var. intermedia are very similar in all morphological characters examined. Cross sections of their distal awn segments do, however, show consistent distinguishing characters; those of var. intermedia are more heavily lignified and tend to be square in outline compared with those of var. comata. Although similar to each other, cross sections of the varieties of S. comata are distinct from those of S. spartea and S. curtiseta. The possibility that certain specimens were hybrids between S. comata var. comata and S. curtiseta was explored and rejected. Distribution maps and a key to the accepted taxa are given.

scholarly journals Determining Ploidy Level and Nuclear DNA Content in Rubus by Flow Cytometry

2002 ◽  
Vol 127 (5) ◽  
pp. 767-775 ◽  
Author(s):  
Rengong Meng ◽  
Chad Finn
Keyword(s):  
Flow Cytometry ◽  
Pacific Northwest ◽  
Ploidy Level ◽  
Dna Content ◽  
Chromosome Numbers ◽  
Nuclear Dna ◽  
Diploid Species ◽  
Nuclear Dna Content ◽  
Dna Flow Cytometry ◽  
Ploidy Levels

Nuclear DNA flow cytometry was used to differentiate ploidy level and determine nuclear DNA content in Rubus. Nuclei suspensions were prepared from leaf discs of young leaves following published protocols with modifications. DNA was stained with propidium iodide. Measurement of fluorescence of 40 genotypes, whose published ploidy ranged from diploid to dodecaploid, indicated that fluorescence increased with an increase in chromosome number. Ploidy level accounted for 99% of the variation in fluorescence intensity (r2 = 0.99) and variation among ploidy levels was much higher than within ploidy levels. This protocol was used successfully for genotypes representing eight different Rubus subgenera. Rubus ursinus Cham. and Schldl., a native blackberry species in the Pacific Northwest, which has been reported to have 6x, 8x, 9x, 10x, 11x, and 12x forms, was extensively tested. Genotypes of R. ursinus were predominantly 12x, but 6x, 7x, 8x, 9x, 11x, and 13x forms were found as well. Attempts to confirm the 13x estimates with manual counts were unsuccessful. Ploidy level of 103 genotypes in the USDA-ARS breeding program was determined by flow cytometry. Flow cytometry confirmed that genotypes from crosses among 7x and 4x parents had chromosome numbers that must be the result of nonreduced gametes. This technique was effective in differentiating chromosome numbers differing by 1x, but was not able to differentiate aneuploids. Nuclear DNA contents of 21 diploid Rubus species from five subgenera were determined by flow cytometry. Idaeobatus, Chamaebatus, and Anaplobatus were significantly lower in DNA content than those of Rubus and Cylactis. In the Rubus subgenus, R. hispidus and R. canadensis had the lowest DNA content and R. sanctus had the highest DNA content, 0.59 and 0.75 pg, respectively. Idaeobatus had greater variation in DNA content among diploid species than the Rubus subgenus, with the highest being from R. ellipticus (0.69 pg) and lowest from R. illecebrosus (0.47 pg).

scholarly journals Chromosome numbers of some species of Pteris (Pteridaceae) in Java, Indonesia

2018 ◽  
Vol 19 (6) ◽  
pp. 2118-2126
Author(s):  
TITIEN NGATINEM PRAPTOSUWIRYO ◽  
MUGI MUMPUNI
Keyword(s):  
Chromosome Number ◽  
Morphological Variation ◽  
Chromosome Numbers ◽  
Diploid Species ◽  
Somatic Chromosome Number ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Central Java ◽  
Fern Species ◽  
Pteris Multifida

Praptosuwiryo TNg, Mumpuni M. 2018. Chromosome numbers of some species of Pteris (Pteridaceae) in Java, Indonesia. Biodiversitas 19: 2118-2126. Pteris L. (Pteridaceae) is a large fern genus consisting of about 250 species which distributed predominantly in tropical and subtropical countries. The genus grows in a diversity of ecosystems, either terrestrially or lithophytically, although most species occur in the forest. A study of the cytology of Pteris in Java is being undertaken for the conceptual understanding of the interrelationships between various fern species in the Malesian region. This aims of our study are: (1) to observe somatic chromosome number of some species of Pteris in Java; (2) to determine the reproduction types of the observed species by counting the spore number per sporangium; (3) to discuss polyploidy in the species in relation to plant morphological variation across their geographical distribution. Chromosome counts for eight species are reported. Pteris biaurita is an apogamous diploid species (2n = 58). Pteris ensiformis var. ensiformis has chromosome numbers of 2n = 87 (apogamous triploid) and 2n = 116 (sexual tetraploid), while                 P. ensiformis var. victoriae has a chromosome number 2n = 58 and is a sexual diploid. Pteris fauriei is an apogamous triploid species (2n = 87). Pteris longipinnula has a chromosome number of 2n = 116 (tetraploid). Pteris multifida and P. vittata are sexual tetraploids (2n=116). Pteris tripartita has two ploidy levels (sexual diploid and tetraploid). Another currently unplaced Javanese Pteris sp. has 2n = 87 (apogamous triploid). Diploid P. biaurita, tetraploid P. ensiformis, triploid P. fauriei, diploid P. tripartita, and teraploid P. vittata are new record cytotypes for Central Java. Polyploidy in the genus in relation to plant morphological variation across its geographical range is discussed.

scholarly journals 439 PB 218 CHROMOSOMAL VARIATION AMONG PROGENY OF FACULTATIVE APOMICTIC GUAYULE

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 494b-494
Author(s):  
Dennis T. Ray ◽  
Youngkoo Cho
Keyword(s):  
Leaf Area ◽  
Plant Height ◽  
Reproductive Biology ◽  
Ploidy Level ◽  
Chromosome Numbers ◽  
Morphological Characters ◽  
Chromosomal Variation ◽  
Mother Cells ◽  
Apomictic Reproduction

Progress toward the domestication of guayule (Parrhenium argentatum Gray) as a domestic source of latex, has been slowed because of its complicated reproductive biology. This work was performed to help elucidate the facultative nature of apomictic reproduction in guayule. Ploidy level and six morphological characters were measured in one-hundred and eighty open-pollinated, half-sib progeny derived from twelve different apomictic tetraploid (4n=4x=72) female parents. The number of chromosomes observed among the half-sib progeny varied from 36 to 81, with the majority (77.3%) of the progeny with 72 chromosomes. All of the observed chromosome numbers could be explained either by meiotic reduction in the megaspore mother cells or fertilization of egg cells or both. The frequencies of meiotic reduction and fertilization resulting in these progeny were estimated to be 27.2 and 22.7%, respectively. Among the six measured morphological characters, significant correlations were found only between chromosome numbers and plant height (r=0.37) and leaf area (r=0.31).

scholarly journals Genome Size Estimates and Chromosome Numbers of Callicarpa L. (Lamiaceae)

HortScience ◽  
2011 ◽  
Vol 46 (4) ◽  
pp. 567-570 ◽  
Author(s):  
Ryan N. Contreras ◽  
John M. Ruter
Keyword(s):  
Flow Cytometry ◽  
Chromosome Number ◽  
Genome Size ◽  
Chromosome Numbers ◽  
Chromosome Counts ◽  
Ploidy Levels ◽  
Flow Cytometry Data ◽  
Carbol Fuchsin ◽  
Cross Compatibility ◽  
Size Estimates

Genome size estimates and chromosome number information can be useful for studying the evolution or taxonomy of a group and also can be useful for plant breeders in predicting cross-compatibility. Callicarpa L. is a group of ≈140 species with nearly worldwide distribution. There are no estimates of genome size in the literature and the information on chromosome numbers is limited. Genome size estimates based on flow cytometry are reported here for 16 accessions of Callicarpa comprising 14 species in addition to chromosome counts on six species. Chromosome counts were conducted by staining meristematic cells of roots tips using modified carbol fuchsin. Holoploid genome size estimates ranged from 1.34 pg to 3.48 pg with a mean of 1.74 pg. Two tetraploids (2n = 4x = 68; C. salicifolia P'ei & W. Z. Fang and C. macrophylla Vahl GEN09-0081) were identified based on holoploid genome size and confirmed by chromosome counts. There was little variation among species for monoploid genome size. 1Cx-values ranged from 0.67 pg to 0.88 pg with a mean of 0.77 pg. Chromosome counts for six species revealed a base chromosome number of x = 17. Callicarpa chejuensis Y. H. Chung & H. Kim, C. japonica Thunb. ‘Leucocarpa’, C. longissima Merr., and C. rubella Lindl. were confirmed as diploids (2n = 2x = 34). Cytology supported flow cytometry data that C. salicifolia and C. macrophylla GEN09-0081 were tetraploids. The two accessions of C. macrophylla included in the study were found to be of different ploidy levels. The presence of two ploidy levels among and within species indicates that polyploidization events have occurred in the genus.

Characterizing polyploidy in Arabidopsis lyrata using chromosome counts and flow cytometry

2004 ◽  
Vol 82 (2) ◽  
pp. 185-197 ◽  
Author(s):  
Sara Dart ◽  
Paul Kron ◽  
Barbara K Mable
Keyword(s):  
Flow Cytometry ◽  
North America ◽  
Dna Content ◽  
Geographic Range ◽  
Chromosome Counts ◽  
Dynamic Nature ◽  
Ploidy Levels ◽  
Arabidopsis Lyrata ◽  
Genomic Changes ◽  
European Populations

Protocols were developed for both chromosome counts and flow cytometry to assess ploidy level and DNA content for populations of Arabidopsis lyrata L. sampled from Europe (Arabidopsis lyrata subsp. petraea), North America (Arabidopsis lyrata subsp. lyrata), and Japan (Arabidopsis lyrata subsp. kawasakiana). Ploidy variation within this species is not clear, with previous studies having documented both diploid and tetraploid populations. Chromosome counts in this study confirmed ploidy expectations for all populations examined. Individuals from Iceland and North America were diploid (2n = 2x = 16), whereas those from Japanese and Austrian populations were tetraploid (2n = 4x = 32). Flow cytometry was also used successfully to distinguish between ploidy levels, but the need to calibrate DNA content measures with chromosome counts was demonstrated by a deviation from the expected 2:1 ratio between tetraploid and diploid values among European populations (A. lyrata subsp. petraea). This deviation might be explained by a hybrid (allopolyploid) origin or by genomic changes following polyploidization, emphasizing the dynamic nature of polyploid genomes. Variation in DNA content among families was found only for North American populations, but these individuals were sampled from a broader geographic range than those from other regions.Key words: cytogenetics, flow cytometry, polyploidy, Arabidopsis lyrata, genome size, chromosome counts.

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