CHROMOSOME NUMBERS OF SOME NORTH AMERICAN DRAGONFLIES (ODONATA)

1968 ◽  
Vol 10 (1) ◽  
pp. 200-214 ◽  
Author(s):  
Robert William Cruden
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Alternative Hypothesis ◽  
Leucorrhinia Frigida

Chromosome numbers for 111 species of North American Odonata are reported. In five species, Enallagma cyathigerum (Charp.), Ophiogomphus bison Sclys, Dorocordulia iibera (Selys), Epitheca cynosura (Say), and Leucorrhinia frigida Hagen, primary spermatocytes from single individuals had different chromosome numbers. This is presumed to arise from either fusion or "splitting" of chromosomes. Fusion in D. libera, E. cynosura and L. frigida results in reduction of chromosome number, and "splitting" in E. cyathigerum and O. bison gives higher chromosome numbers.The idea that high chromosome numbers in Odonata are primitive is rejected. An alternative hypothesis is proposed: that low numbers are primitive (or secondarily derived) and high numbers advanced.

Chromosome numbers of 15 North American bumble bee species (Hymenoptera, Apidae, Bombini)

1983 ◽  
Vol 25 (1) ◽  
pp. 26-29
Author(s):  
Robin E. Owen
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Bumble Bees ◽  
Bumble Bee ◽  
Morphological Divergence ◽  
Chromosome Counts ◽  
Monophyletic Origin ◽  
The Social

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.

The chromosome numbers of five North American and European leech species

1987 ◽  
Vol 65 (3) ◽  
pp. 681-684 ◽  
Author(s):  
Ronald W. Davies ◽  
R. N. Singhal
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Chromosome Evolution ◽  
Chromosome Counts ◽  
Prophase I ◽  
Metaphase I

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.

Chromosome numbers from pollen in some North American Impatiens (Balsaminaceae)

1974 ◽  
Vol 52 (12) ◽  
pp. 2637-2639 ◽  
Author(s):  
C. C. Chinnappa ◽  
L. S. Gill
Keyword(s):  
North America ◽  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Herbarium Specimens ◽  
Chromosome Counts ◽  
Present Survey ◽  
The One ◽  
Basic Numbers

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.

Chromosome numbers of some North American Arctic and Boreal Salix

1969 ◽  
Vol 47 (6) ◽  
pp. 859-862 ◽  
Author(s):  
Yutaka Suda ◽  
G. W. Argus
Keyword(s):  
Chromosome Number ◽  
North American ◽  
Chromosome Numbers ◽  
Population Variation ◽  
The Arctic ◽  
Natural Hybrid ◽  
Boreal Species ◽  
Arctic Species ◽  
Native North American ◽  
North American Arctic

Chromosome numbers are reported for 12 native North American species of Salix and one natural hybrid. The arctic species Salix alaxensis var. alaxensis, S. fuscescens, S. ovalifolia var. ovalifolia, S. phlebophylla, and S. reticulata and the boreal species S. arbusculoides are diploids, 2n = 38. Tetraploid counts, 2n = 76, are reported for the arctic S. planifolia ssp. pulchra. Taxa with more than one chromosome number include S. planifolia ssp. planifolia and S. pedicellaris, each of which has tetraploid and triploid levels; S. arctica s.l., which is tetraploid in the eastern American arctic and hexaploid in the Alaska and Eurasian arctic; and S. athabascensis with triploid, tetraploid, and hexaploid levels. Intra-population variation in chromosome number is reported for S. glauca in which tetraploids, pentaploids, and hexaploids occur in a single Alaskan population.

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 Estudios cromosómicos en Lycium (Solanaceae) de Norteamérica

2017 ◽  
pp. 9
Author(s):  
Fernando Chiang
Keyword(s):  
Chromosome Number ◽  
Pollen Mother Cell ◽  
North American ◽  
Chromosome Numbers ◽  
Mother Cell ◽  
Mitotic Chromosome ◽  
Single Case ◽  
Meiotic Chromosome ◽  
The World ◽  
Base Chromosome Number

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.

CHROMOSOME NUMBER DETERMINATIONS IN FAMILY COMPOSITAE, TRIBE ASTEREAE. IX. NORTH AMERICAN TAXA. II

Rhodora ◽  
10.3119/18-07 ◽  
2019 ◽  
Vol 121 (985) ◽  
pp. 37 ◽  
Author(s):  
John C. Semple ◽  
Rachel E. Cook ◽  
Gary H. Morton ◽  
James B. Beck ◽  
Rita Lopez Laphitz
Keyword(s):  
Chromosome Number ◽  
North American

CYTOTAXONOMY, PHYLOGENY, AND CANADIAN DISTRIBUTION OF CIRSIUM UNDULATUM AND CIRSIUM FLODMANII

1961 ◽  
Vol 39 (1) ◽  
pp. 21-33 ◽  
Author(s):  
C. Frankton ◽  
R. J. Moore
Keyword(s):  
North American ◽  
Chromosome Numbers ◽  
World Wide ◽  
North American Species ◽  
Base Number ◽  
Total Length ◽  
The World ◽  
Cirsium Undulatum

The morphology and specific differences of Cirsium undulatum (Nutt.) Spreng. and of C. flodmanii (Rydb.) Arthur are described and their Canadian distributions are reported in detail. The chromosome numbers are C. undulatum f. undulatum and f. album Farwell, 2n = 26; C. flodmanii f. flodmanii and f. albiflorum D. Löve, 2n = 22. The origin of four North American species of Cirsium that do not follow the world-wide base number 17 is discussed; it is postulated that reduction in number has occurred by translocations. The chromosomes of species with reduced numbers are larger than those of the unreduced species but the total length of the chromosomes of both groups is approximately the same.

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.

scholarly journals Karyotype Analysis of Alnus Mill. (Betulaceae) Species Originating From Northeastern Asia

2010 ◽  
Vol 59 (1-6) ◽  
pp. 219-223 ◽  
Author(s):  
Liu Jun ◽  
Ren Bao-Qing ◽  
Luo Peigao ◽  
Ren Zhenglong
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Karyotype Analysis ◽  
Full Potential ◽  
Northeastern Asia ◽  
Ploidy Levels ◽  
Genetic Makeup ◽  
Fossil Records

Abstract Alnus Mill. (alder) is an ecologically valuable tree genus. It is essential to study its genetic makeup in order to use alder trees to their full potential. Five specimens from four Alnus species (A. mandshurica, A. pendula, A. sibirica, and A. sieboldiana), found in northeastern Asia, were subjected to karyotype analysis. The analysis showed that these tree samples could be divided into three categories based on chromosome numbers or ploidy levels: viz., 2n = (4x) = 28, 2n = (8x) = 56 and 2n = (16x) = 112. The differences in chromosome number and karyotype parameters among Alnus species and even within the same species possibly resulted from natural polyploidization. Comparing the chromosome numbers of Alnus species in China with those in Japan showed that there appear to be only two categories in China, whereas there are up to five categories in Japan. The earliest fossil records of Alnus pollen were also discovered in Japan. We conclude that the center origin of Alnus spp. is Japan rather than China.

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