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 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.

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.

Karyotypes of Leptarrhena and Tanakaea (Saxifragaceae)

1984 ◽  
Vol 62 (4) ◽  
pp. 671-673 ◽  
Author(s):  
Douglas E. Soltis
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosomal Evolution ◽  
Conservative Nature ◽  
Chromosomal Data ◽  
Base Chromosome Number ◽  
Flavonoid Chemistry

In an attempt to clarify subtribal relationships in tribe Saxifrageae, chromosome numbers and karyotypes were determined for the two species comprising subtribe Leptarrheninae: Leptarrhena pyrolifolia and Tanakaea radicans. In both species 2n = 14, a common chromosome number throughout Saxifrageae. The two species have distinctive karyotypes that appear to differ in the centromeric positions of three pairs of chromosomes. These findings, in conjunction with earlier studies, demonstrate that genera of Saxifrageae often differ karyotypically. Leptarrhena exhibits considerable karyotypic similarity to genera of subtribe Saxifraginae characterized by a base chromosome number of x = 7. Chromosomal data, therefore, do not clearly differentiate subtribes Saxifraginae and Leptarrheninae. This observation is in agreement with evidence from paly-nology and flavonoid chemistry. Karyotypic studies continue to demonstrate the conservative nature of chromosomal evolution in tribe Saxifrageae.

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.

scholarly journals Developmental sequence of chromosome number in a cytologically unstable Rubus hybrid

1961 ◽  
Vol 2 (1) ◽  
pp. 10-24 ◽  
Author(s):  
G. Haskell ◽  
N. N. Tun
Keyword(s):  
Chromosome Number ◽  
Virus Infection ◽  
Chromosome Numbers ◽  
Mother Cell ◽  
Root Tip ◽  
Developmental Sequence ◽  
General Increase ◽  
Incremental Change ◽  
Rubus Species

1. Serial cytological observations were made on one abnormal seedling from the thornless segregants of the F2 progeny from crossing two tetraploid (2n = 28) Rubus species. The number of root-tip chromosomes was found to vary between 9 and 46 per cell, with the mode always at 35. The wide variation in chromosome number decreased with time, until there was almost stability at 2n = 35. A vegetative (stipule) cell was 2n = 39. The numbers lower than 35 were not due to terminal fusion.2. Evidence from the number of satellites per cell suggests that not always were the same chromosomes being eliminated, although there is a general increase in satellite number with increased numbers of chromosomes per cell.3. There was a correlation between the chromosome numbers and corresponding cell sizes within the aneuploid series. This may be associated with the incremental change of DNA following the addition or subtraction of individual chromosomes, which are highly similar in Rubus.4. The cause of the instability was not definitely established. Its initiation is probably attributable to the egg mother cell, as Rubus pollen reacts sensitively to chromosome unbalance. No abnormalities were observed in the mitoses, and virus infection was not responsible for the instability.5. Chromosome number instability of this plant is discussed in relation to other examples from the same and different genera: it is suggested that the changes in chromosome number known in various Rubi may have arisen somatically.

Chromosome Number Variation in the Myrtaceae and Its Taxonomic Implications

1979 ◽  
Vol 27 (5) ◽  
pp. 547 ◽  
Author(s):  
BL Rye
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Evolutionary Potential ◽  
The Family ◽  
Number Variation ◽  
Taxonomic Implications ◽  
Chromosome Number Variation ◽  
Australian Flora ◽  
Base Chromosome Number ◽  
Western Australian

New chromosome number determinations are reported for some 150 Western Australian species of the Myrtaceae. These include the lowest number (n = 5) so far recorded in the family and several newly recorded descending dysploid series. Dysploid chromosome numbers are far less common than the base chromosome number of n = 11 but parallel dysploid series have occurred in many groups and some have played a role in the origin of genera. Polyploidy has been successful at the intraspecific and interspecific levels but is of limited evolutionary potential. The cytoevolutionary trends in the Myrtaceae are examined in relation to taxonomic problems within the family and in relation to cytoevolution in the woody Australian flora as a whole. Smith- White's suggestion that a more natural generic classification in the Chamelauciinae could be obtained by grouping species with the same base chromosome numbers is found to be untenable.

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.

scholarly journals A checklist of chromosome numbers and a review of karyotype variation in Odonata of the world

2020 ◽  
Vol 14 (4) ◽  
pp. 501-540
Author(s):  
Valentina G. Kuznetsova ◽  
Natalia V. Golub
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Sex Chromosome ◽  
The Other ◽  
Local Modes ◽  
Insect Order ◽  
Extant Species ◽  
The World ◽  
Phylogenetic Lineages ◽  
Sex Determination Mechanisms

The ancient insect order Odonata is divided into three suborders: Anisoptera and Zygoptera with approximately 3000 species worldwide each, and Anisozygoptera with only four extant species in the relict family Epiophlebiidae. An updated list of Odonata species studied regarding chromosome number, sex chromosome mechanism and the occurrence of m-chromosomes (= microchromosomes) is given. Karyotypes of 607 species (198 genera, 23 families), covering approximately 10% of described species, are reported: 423 species (125 genera, 8 families) of the Anisoptera, 184 species (72 genera, 14 families) of the Zygoptera, and one species of the Anisozygoptera. Among the Odonata, sex determination mechanisms in males can be of X(0), XY and X1X2Y types, and diploid chromosome numbers can vary from 6 to 41, with a clear mode at 2n = 25(60%) and two more local modes at 2n = 27(21%) and 2n = 23(13%). The karyotype 2n = 25(24A + X) is found in each of the three suborders and is the most typical (modal) in many families, including the best-covered Libellulidae, Corduliidae (Anisoptera), Lestidae, Calopterygidae, and Platycnemididae (Zygoptera). This chromosome set is considered ancestral for the Odonata in general. Chromosome rearrangements, among which fusions and fissions most likely predominated, led to independent origins of similar karyotypes within different phylogenetic lineages of the order. The karyotype 2n = 27(26A + X) prevails in Aeshnidae and Coenagrionidae, whereas the karyotype 2n = 23(22A + X) is modal in Gomphidae and Chlorocyphidae, in both pairs of families one being from the Anisoptera while the other from the Zygoptera.

scholarly journals A checklist of chromosome numbers and a review of karyotype variation in Odonata of the world

2020 ◽  
Vol 14 (4) ◽  
pp. 501-540
Author(s):  
Valentina G. Kuznetsova ◽  
Natalia V. Golub
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Sex Chromosome ◽  
The Other ◽  
Local Modes ◽  
Insect Order ◽  
Extant Species ◽  
The World ◽  
Phylogenetic Lineages ◽  
Sex Determination Mechanisms

The ancient insect order Odonata is divided into three suborders: Anisoptera and Zygoptera with approximately 3000 species worldwide each, and Anisozygoptera with only four extant species in the relict family Epiophlebiidae. An updated list of Odonata species studied regarding chromosome number, sex chromosome mechanism and the occurrence of m-chromosomes (= microchromosomes) is given. Karyotypes of 607 species (198 genera, 23 families), covering approximately 10% of described species, are reported: 423 species (125 genera, 8 families) of the Anisoptera, 184 species (72 genera, 14 families) of the Zygoptera, and one species of the Anisozygoptera. Among the Odonata, sex determination mechanisms in males can be of X(0), XY and X1X2Y types, and diploid chromosome numbers can vary from 6 to 41, with a clear mode at 2n = 25(60%) and two more local modes at 2n = 27(21%) and 2n = 23(13%). The karyotype 2n = 25(24A + X) is found in each of the three suborders and is the most typical (modal) in many families, including the best-covered Libellulidae, Corduliidae (Anisoptera), Lestidae, Calopterygidae, and Platycnemididae (Zygoptera). This chromosome set is considered ancestral for the Odonata in general. Chromosome rearrangements, among which fusions and fissions most likely predominated, led to independent origins of similar karyotypes within different phylogenetic lineages of the order. The karyotype 2n = 27(26A + X) prevails in Aeshnidae and Coenagrionidae, whereas the karyotype 2n = 23(22A + X) is modal in Gomphidae and Chlorocyphidae, in both pairs of families one being from the Anisoptera while the other from the Zygoptera.

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