CYTOTAXONOMY OF THREE SPECIES OF CENTAUREA ADVENTIVE IN CANADA

1954 ◽  
Vol 32 (1) ◽  
pp. 182-186 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton
Keyword(s):  
Chromosome Number ◽  
Introduced Species ◽  
Chromosome Numbers ◽  
Diploid Chromosome Number ◽  
Chromosome Counts ◽  
Normal Pollen ◽  
Taxonomic Problem ◽  
First Time

The chromosome numbers of three introduced species of Centaurea are here reported: C. diffusa Lam., 2n = 18; C. maculosa, Lam., 2n = 36; C. repens L., 2n = 26. The chromosome counts of C. diffusa and of C. maculosa, which are here reported for the first time, help to clarify a taxonomic problem. A pappus is usually lacking on the achenes of C. diffusa but is present on those of C. maculosa. As a result, plants of C. diffusa with a short pappus have been considered to be possible hybrids between these species. Three such plants here studied had the diploid chromosome number 18, rather than the triploid number to be expected in such a hybrid. Examination of pollen of suspected hybrid specimens shows that the percentage of normal pollen is high. This fact also supports the belief that plants of C. diffusa with a short pappus on the achene are not hybrids with C. maculosa.

scholarly journals Chromosome number and meiotic behavior in several plant taxa from iran

2021 ◽  
Vol 45 (2) ◽  
pp. 333-339
Author(s):  
Seyed Ghaffari ◽  
Abbas Zare ◽  
Fereshteh Corom ◽  
Masoureh Sedaghati
Keyword(s):  
Chromosome Number ◽  
Endemic Species ◽  
Chromosome Numbers ◽  
Mitotic Chromosome ◽  
Vascular Plant ◽  
Meiotic Behavior ◽  
Chromosome Counts ◽  
Plant Families ◽  
First Time ◽  
Accessory Chromosomes

Original meiotic or both meiotic and mitotic chromosome numbers are reported for ten endemic and one non endemic species in nine vascular plant families from Iran. The chromosome numbers of Acantholimon schahrudicum, A. truncatum, Anthochlamys multinervis, Campanula perpusilla, Cousinia calcitrapa var. interrupta, Dorema ammoniacum, Euphorbia gedrosiaca, and Hyocyamus orthocarpus were determined for the first time. The chromosome counts for Astrodaucus persicus and Hedysarum criniferum agree with previous ones. The gametic chromosome numbers for Hedysarum criniferum and Allium stipitatum are reported here for the first time. The occurrence of accessory chromosomes are also reported for Acantholimon schahrudicum and Dorema ammoniacum, being the first records of B chromosomes in the genera Acantholimon and Dorema.

CYTOTAXONOMY OF THE SPECIES AND INTERSPECIFIC HYBRIDS OF THE GENUS AGROPYRON IN CANADA AND NEIGHBORING AREAS

1965 ◽  
Vol 43 (11) ◽  
pp. 1421-1448 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
United States ◽  
Chromosome Number ◽  
Introduced Species ◽  
Chromosome Numbers ◽  
Interspecific Hybrid ◽  
Native Species ◽  
Interspecific Hybrids ◽  
Natural Hybrids ◽  
Voucher Specimens ◽  
First Time

A cytotaxonomic treatment is given for 10 native species, 4 introduced species, and 8 natural interspecific hybrids of the genus Agropyron Gaertner that occur in Canada. Five of the native Agropyron species, one introduced species, and one natural interspecific hybrid are also found in Alaska. Eight of the native species, the four introduced species, and four natural interspecific hybrids are present in the mainland United States. Four additional native species and five additional introduced species that occur in the mainland United States are considered briefly.Nomenclatural proposals include: Agropyron dasystachyum (Hook.) Scribn. var. riparium (Scribn. & Smith) Bowden; Agropyron × pseudorepens Scribn. & Smith (pro sp.) nm. pseudorepens and nm. vulpinum (Rydb.) Bowden (A. dasystachyum × A. trachycaulum); and Agropyron × brevifolium Scribn. (pro sp.) (A. scribneri × A. violaceum).Voucher specimens are cited for chromosome number determinations of the native and introduced Agropyron species and some natural and artificial interspecific hybrids. Chromosome numbers are reported for the first time for A. violaceum (2n = 28), A. yukonense (2n = 28), the natural hybrids A. × pseudorepens nm. pseudorepens and nm. vulpinum (2n = 28), A. dasystachyum × A. spicatum (2n = 21), and A. violaceum × A. yukonense (2n = 28), and four artificial interspecific hybrids. Seven natural hybrids and four artificial hybrids are reported for the first time.

Cytotaxonomy of some Cirsium species of the eastern United States, with a key to eastern species

1969 ◽  
Vol 47 (8) ◽  
pp. 1257-1275 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton
Keyword(s):  
United States ◽  
North America ◽  
Chromosome Number ◽  
Introduced Species ◽  
The United States ◽  
Eastern North America ◽  
Eastern United States ◽  
Chromosome Counts ◽  
First Time ◽  
Eastern Species

The morphology and chromosome number of nine species of Cirsium of eastern North America are considered. Chromosome counts are presented for the first time for C. iowense, 2n = 18; C. lecontei, 2n = 32; C. nuttallii, 2n = 24, 28; C. repandum, 2n = 30; C. smallii, 2n = 34; C. engelmannii, 2n = 20; C. texanum, 2n = 22, 24; C. virginianum, 2n = 28. Additional chromosomes, possibly to be considered as accessories, were found in C. nuttallii, C. engelmannii, and C. texanum. These chromosomes render uncertain the number characteristic of these species. A key to the 26 native and introduced species found in Canada and the United States east of 100° west latitude is presented. The interrelationships of the eastern species and of the species of the western series Undulata are discussed.

Chromosome numbers and the taxonomy of North American Agalinis (Scrophulariaceae)

1984 ◽  
Vol 62 (3) ◽  
pp. 454-456 ◽  
Author(s):  
Judith M. Canne
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Base Number ◽  
Chromosome Counts ◽  
Base Chromosome Number ◽  
First Time

Chromosome counts are provided for 25 populations representing 18 species of Agalinis Raf. Chromosome numbers are reported for the first time for A. pinetorum, A. laxa, A. acuta, A. gattingeri, and A. skinneriana. The base chromosome number for section Linifoliae, section Heterophyllae, section Purpureae subsections Purpureae and Setaceae, and section Tenuifoliae is established at x = 14. Section Erectae and section Purpureae subsection Pedunculares have a base number of x = 13.

scholarly journals Chromosome counts inGaultheriaand related genera

1990 ◽  
Vol 47 (3) ◽  
pp. 303-313 ◽  
Author(s):  
D. J. Middleton ◽  
C. C. Wilcock
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosome Counts ◽  
First Time

The chromosome numbers of 32 taxa in the ‘Gaultheria group’ of genera of the tribe Andromedeae in the Ericaceae have been counted; 15 of these have been counted for the first time. All taxa counted inGaultheriaandLeucothoëhave a chromosome number based on x = 11. The chromosome numbers counted inDiplycosiaare 2n = 36 and inZenobia2n = c.66.G. insanaandG. procumbensshow different polyploid races:G. insanatetraploids and hexaploids andG. procumbensdiploids, tetraploids and octoploids.

scholarly journals New Contribution to the Knowledge on the Chromosome Numbers of Turkish Cerambycidae (Coleoptera)

2021 ◽  
Vol 69 (2) ◽  
pp. 93-99
Author(s):  
Yavuz Koçak ◽  
Elmas Yağmur
Keyword(s):  
Chromosome Number ◽  
Sex Determination ◽  
Chromosome Numbers ◽  
Chromosome Count ◽  
Chromosomal Number ◽  
The Poor ◽  
Karyological Data ◽  
First Time

Information on the karyotypes of Turkish species of Cerambycidae is scanty. Our study contributes to the knowledge of the karyological data (chromosomal number and mechanism of sex determination) of five Turkish longicorn beetles; karyotypes of four taxa, one endemic, are described for the first time and for the remaining one, Purpuricenus budensis (Götz, 1783), the previously published chromosome count is confirmed. The chromosome number of Purpuricenus desfontainii inhumeralis Pic, 1891 and Purpuricenus budensis (Götz, 1783) (Cerambycinae, Trachyderini) was found to be 2n = 28 (13 + Xyp); Clytus rhamni Germar, 1817 and Plagionotus floralis (Pallas, 1773) (Cerambycinae, Clytini) 2n = 20 (9 + Xyp); and the endemic Dorcadion triste phrygicum Peks, 1993 (Lamiinae, Dorcadionini) 2n = 24 (11 + Xyp). In view of the paucity of data available until now, our study is important for both to improve the poor karyological knowledge of Turkish Cerambycidae and to provide an incentive for other researchers.

The Chromosome Numbers and Nuclear Cytology of Some Common British Serpulids

1960 ◽  
Vol s3-101 (56) ◽  
pp. 395-400
Author(s):  
S. DASGUPTA ◽  
A. P. AUSTIN
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Cells ◽  
Diploid Chromosome Number ◽  
Iron Alum ◽  
Artificial Fertilization ◽  
Nuclear Cytology

The chromosome numbers of Hydroides norvegica, Mercierella enigmatica, and Pomatoceros triqueter were determined from squashes of somatic cells in young embryos obtained by artificial fertilization, and stained with iron-alum/aceto-carmine. All had a diploid count of zn = 26 chromosomes. Mitotic and meiotic divisions in the 5 species of Spirorbis examined, and in Filograna implexa, all revealed a diploid chromosome number of 2n = 20. A diploid chromosome number of 14 is suggested for the ancestral serpulid.

Chromosome studies on African plants. 9. Chromosome numbers in Ehrharta (Poaceae: Ehrharteae)

Bothalia ◽  
1989 ◽  
Vol 19 (1) ◽  
pp. 125-132 ◽  
Author(s):  
J. J. Spies ◽  
E. J. L. Saayman ◽  
S. P. Voges ◽  
G. Davidse
Keyword(s):  
Chromosome Number ◽  
Ploidy Level ◽  
Chromosome Numbers ◽  
Basic Chromosome Number ◽  
B Chromosomes ◽  
Basic Chromosome ◽  
Cytogenetic Studies ◽  
African Plants ◽  
First Time

Cytogenetic studies of 53 specimens of 14 species of the genus  Ehrharta Thunb. confirmed a basic chromosome number of 12 for the genus. Chromosome numbers for 13 species are described for the first time. The highest ploidy level yet observed in the genus (2n = lOx = 120) is reported for E. villosa var.  villosa. B chromosomes were observed in several specimens of four different species.

Can morphology and chromosome number contribute to species delimitation? A case in the Hibiscus trionum complex (Tribe Hibisceae, Malvaceae)

Phytotaxa ◽  
2019 ◽  
Vol 416 (4) ◽  
pp. 278-286
Author(s):  
MOHAMED OWIS BADRY ◽  
JENNIFER A. TATE ◽  
PRASHANT JOSHI ◽  
AHMED MAHMOUD ABBAS ◽  
SOHAIR THABET HAMED ◽  
...  
Keyword(s):  
Chromosome Number ◽  
Species Delimitation ◽  
Taxonomic Revision ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Comprehensive Description ◽  
Hibiscus Trionum ◽  
The World ◽  
First Time

A taxonomic revision of Hibiscus trionum from Egypt was undertaken using morphological and cytological studies of field collections and herbarium specimens. The data indicate that all specimens so far collected in Egypt belong to H. tridactylites, rather than H. trionum. This paper includes a comprehensive description of H. tridactylites, its occurrence, a comparison with other species in the H. trionum complex, and comments on habitat, along with images for easy identification. In addition, chromosome counts for this species from Egypt have been determined for the first time, which add to existing information on chromosome counts for the species from different regions of the world.

Diploidy, polyploidy, and agamospermy among species of Eupatorium (Compositae)

1976 ◽  
Vol 54 (24) ◽  
pp. 2907-2917 ◽  
Author(s):  
Victoria I. Sullivan
Keyword(s):  
Normal Embryo ◽  
Herbarium Specimens ◽  
Pollen Production ◽  
Chromosome Counts ◽  
Distribution Maps ◽  
Normal Pollen ◽  
Abortive Pollen ◽  
Chromosomal Pairing ◽  
First Time

Diploids of eight species of Eupatorium, triploids of three species, and tetraploids of four species are reported here for the first time. Meiosisin microsporocytes of triploids and tetraploids either failed to occur resulting in failure of pollen production or less frequently resulted in either incomplete chromosomal pairing or complete asynapsis; the latter two events lead to the production of grossly malformed, abortive pollen with unevenly deposited walls. Megasporogenesis examined in two polyploid plants led to the formation of eight-nucleate, unreduced embryo sacs which formed endosperm and embryos without pollination, indicating that the sporophytes develop asexually through agamospermy. Evidence is given that this may be a facultative characteristic. Megasporogenesis, studied in diploids of four species, produced normal embryo sacs with no indication of agamospermous development. Diploid plants of 11 of 12 species were tested and found to be self-incompatible.Since diploids could readily be distinguished from polyploids by pollen production (diploids produced normal pollen, polyploids produced none or malformed pollen), distributions of a large number of diploid, triploid, and tetraploid individuals could be determined from examining anthers of herbarium specimens. Distribution maps were made using these data as well as those from chromosome counts. Diploid members of species having both diploid, triploid, and (or) tetraploid members consistently had smaller distributional ranges than polyploids of the same species.

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