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

1984 ◽  
Vol 62 (3) ◽  
pp. 454-456 ◽  
Author(s):  
Judith M. Canne

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.


1983 ◽  
Vol 25 (1) ◽  
pp. 26-29
Author(s):  
Robin E. Owen

Chromosome counts were obtained for 14 Bombus Latr. species (the social bumble bees) belonging to four subgenera and for one Psithyrus Lep. species (the social parasitic bumble bees). In Bombus the haploid numbers were consistent within each subgenus and there was variation between subgenera; the subgenera Bombus s.s. and Pyrobombus have n = 18, while Separatobombus and Cullumanobombus have n = 19. Thus considerable morphological divergence between subgenera is often, but not always, paralleled by divergence in chromosome number. Psithyrus ashtoni has n = 25, higher than all Bombus species yet examined. This provides support for the monophyletic origin of Psithyrus, but the high n is not expected if eusociality selects for increase in chromosome number.



1987 ◽  
Vol 65 (3) ◽  
pp. 681-684 ◽  
Author(s):  
Ronald W. Davies ◽  
R. N. Singhal

Chromosome counts were obtained for four glossiphoniid species belonging to three genera (Glossiphonia, Theromyzon, Placobdella) and for one erpobdellid species (Dina lineata) of freshwater leeches. Theromyzon rude, which has a Palaearctic distribution, had seven bivalents at prophase I and metaphase I, while the Holarctic T. tessulatum had eight bivalents, giving diploid chromosome numbers of 14 and 16, respectively. Placobdella papillifera from Alberta had a chromosome number of 2n = 24 and Glossiphonia complanata from Alberta and England had chromosome counts of 2n = 28. At prophase I and metaphase I nine bivalents occurred in the majority of the nuclei of Dina lineata. These findings are discussed in relation to the chromosome evolution and phylogenetic schemes proposed by previous authors.



1999 ◽  
Vol 12 (6) ◽  
pp. 781 ◽  
Author(s):  
K. Watanabe ◽  
P. S. Short ◽  
T. Denda ◽  
N. Konishi ◽  
M. Ito ◽  
...  

Chromosome number determinations from 152 collections representing 42 genera and 106 species of the Australian Gnaphalieae and Plucheeae are reported. The chromosome numbers of 75 of these species have not been previously counted or differ from those previously reported for species. Chromosome numbers have been documented for the first time for 14 genera: Argyroglottis (n = 12), Cephalosorus (2n = 24), Decazesia (n = 14), Dielitzia (2n = 26), Eriochlamys (n = 14), Erymophyllum (n = 11 and 14), Gilruthia (n = 13), Leucochrysum (n = 9), Myriocephalus s. str. (n = 14, 2n = 24), Polycalymma s. str. (n = 14), Pterocaulon (n = 10), Pterochaeta (n = 12), Quinetia (2n – 24) and Sondottia (2n = 6). Remaining counts augment and agree with previously reported determinations. Some problems with generic delimitation and interpretation of chromosome data are outlined. There is an array of karyotypes within the Australian Gnaphalieae and dysploidy is widespread. Polyploidy has also played an important role in the evolution of some taxa. Evidence suggests that the base number for Australian Gnaphalieae is x = 14. This may be the base number for the entire tribe.



2021 ◽  
Vol 45 (2) ◽  
pp. 333-339
Author(s):  
Seyed Ghaffari ◽  
Abbas Zare ◽  
Fereshteh Corom ◽  
Masoureh Sedaghati

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.



1974 ◽  
Vol 52 (12) ◽  
pp. 2637-2639 ◽  
Author(s):  
C. C. Chinnappa ◽  
L. S. Gill

Chromosome counts for eight species of Impatiens from North American populations have been determined from herbarium specimens. The chromosome number n = 10 for I. ecalcarata Blank, is a new report. It is apparent from the present survey that there are at least three basic numbers (n = 7, 10, and 13) represented in North America as opposed to the one (n = 10) suggested by the earlier workers.



1954 ◽  
Vol 32 (1) ◽  
pp. 182-186 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton

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.



2017 ◽  
pp. 9
Author(s):  
Fernando Chiang

The results of chromosomal studies reported for species of Lycium of the world are presented. Meiotic chromosome numbers were determined from pollen mother-cell squashes of North American taxa of Lycium. In a single case, a mitotic chromosome number was determined from the radicle of a germinating seed. The taxa studied were: L. andersonii Gray var. andersonii, L. andersonii var. deserticola (C. L. Hitchc.) Jepson, L. andersonii var. pubescens S. Wats., L. andersonii var. wrightii A. Gray, L. berlandieri Dun. var. berlandieri, L. berlandieri var. parviflorum (Gray) Terrac., L. berlandieri var. peninsulare ( Brandeg.) C. L. Hitchc., L. brevipes Benth. var. brevipes, L. californicum Nutt. ex Gray var. californicum, L. californicum var. Arizonicum A. Gray, L. cal.ifornicum var. interior Chiang, L. carolinianum var. Quadrifidum ( Moc. & Sessé ex Dun. ) C. L. Hitchc., L. cooperi A. Gray, L. macrodon A. Gray var. macrodon, L. nodosum var. isthmense ( Chiang) Chiang, L. pallidum Miers var. pallidum, L. parishii A. Gray var. parishii, L. parishii var. modest1tm ( I. M. Johnst.) Chiang, L. puberulum var. berberidoides ( Correll) Chiang, and L. torreyi A. Gray. Chromosome numbers of n = 12, 24, 48, 60, and 2n = 24 were found. It is concluded rhat x = 12 is the base chromosome number for Lycium. The origin of n = 18, previously reported, is discussed.



1990 ◽  
Vol 47 (3) ◽  
pp. 303-313 ◽  
Author(s):  
D. J. Middleton ◽  
C. C. Wilcock

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.



1965 ◽  
Vol 43 (6) ◽  
pp. 657-668 ◽  
Author(s):  
Gerald A. Mulligan

Chromosome numbers and taxonomic discussions are given for North American material of species in the genera Braya and Cardamine. The following chromosome numbers are reported for the first time: Braya humilis s.l., n = 14 and 2n = 28; Cardamine angulata, n = 20, and 2n = 40; C. cordifolia, 2n = 24; C. microphylla, 2n = 32; C. occidentalis, n = 32 and 2n = 64; C. oligosperma, 2n = 16; C. pensylvanica, 2n = 64; C. umbellata, n = 24 and 2n = 48. It is concluded that the base number of Braya is x = 7 not x = 8 and that North American species of Cardamine have the base numbers x = 6, 8, and 10.



Turczaninowia ◽  
2021 ◽  
Vol 24 (2) ◽  
pp. 88-92
Author(s):  
Maryam Keshavarzi ◽  
Samaneh Mosaferi ◽  
Fatemeh Abivardi

Aeluropus, a member of Poaceae subfam. Chloridoideae, includes six species, three of which occur in Iran. They are perennial halophytes of deserts and coastal marshlands of Iran. The genus is considered as a rich genetic source for gene manipulation and using it for crop improvement. Previous studies showed that members of Chloridoideae have small chromosomes and the base chromosome number n = 10. There are few chromosome records for Aeluropus species. Somatic metaphases of seven populations of three Aeluropus species were studied. The first chromosome counts (2n = 20) based on Iranian material for three species, A. macrostachyus, A. littoralis and A. lagopoides, are concordant with previous records outside Iran; mitotic number for A. macrostachyus is recorded here for the first time.



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