scholarly journals 'n Vergelykende studie van die kariotipes van Tilapia rendalli, Tilapia sparrmanii en Oreochromis mossambicus (Cichlidae)

1992 ◽  
Vol 11 (3) ◽  
pp. 105-109 ◽  
Author(s):  
A. Swanepoel
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Chromosome Pair ◽  
Somatic Chromosome ◽  
Oreochromis Mossambicus ◽  
Tilapia Rendalli ◽  
Lymphocyte Cultures ◽  
L1 And L2 ◽  
Somatic Chromosome Numbers ◽  
Standard Techniques

Optimal chromosome preparations were obtained from stimulated lymphocyte cultures with a new method based on a combination and modification of several techniques. Tilapia rendalli, T. sparrmanii and Oreochromis mossambicus have somatic chromosome numbers of 44, 42 and 44, respectively. Chromosome pairs L1 and L2 are easily identified in all the karyotypes and distinctive of the tilapias. Tilapia sparrmanii has one additional large metacentric chromosome pair(L3), which occurs concurrently with the reduction of two in the total chromosome number. The F chromosomes were divided into two groups, viz a submetacentric (sm) and a telocentric (t) group. T. rendalli has 8 sm chromosomes, while both T. sparrmanii and O. mossambicus have 6 chromosomes in the sm group. The rest of the F chromosomes were telocentric. The identification of the sex chromosomes in the karyotypes of tilapia has thus far not been possible using standard techniques.

Cytoevolution of Taxa in Acacia and Prosopis (Mimosaceae)

1997 ◽  
Vol 45 (5) ◽  
pp. 879 ◽  
Author(s):  
Yahya M. Bukhari
Keyword(s):  
Chromosome Numbers ◽  
Chromosome Pair ◽  
Somatic Chromosome ◽  
Structural Changes ◽  
Faidherbia Albida ◽  
Centric Fission ◽  
Somatic Chromosome Numbers ◽  
Diploid Ancestor

Somatic chromosome numbers were reported for 47 accessions of Acacia (Tourn.) Miller, representing 23 species including A. albida (syn. Faidherbia albida), together with 19 accessions (11 species) of Prosopis (L.) Burkart. Microphotographs of somatic metaphases of 12 accessions and six representative idiograms are shown. Somatic numbers of different accessions of a species can be different. Somatic numbers of accessions of subgenus Acacia were predominantly 52; a few had 2n = 78 or 104. However, A. sieberana had 2n = 26 and A. nubica 2n = 56. Except for A. polycantha, which had 2n = 52, somatic numbers of subgenus Aculeiferum were invariably 26. Of the six species of subgenus Heterophyllum studied, five had 26 somatic chromosomes and one (A. holoceraceae) had 52. All the four accessions of A. albida had 2n = 26. Out of the 19 Prosopis accessions investigated, five had 56 somatic chromosomes and 14 accessions had 28. In Acacia, subgeneric and specific differentiations are probably caused by structural changes in the chromosomes, whereas differences in the degree of euploidy appear to create infraspecies. Subgenus Aculeiferum is a possible progenitor of all other taxa of Acacia and Prosopis. The study suggests that Prosopis has diverged later in geological times from a diploid ancestor (2n = 26) of Aculeiferum through centric fission of the second-largest chromosome pair.

A CYTOLOGICAL STUDY OF THE GENUS POA L.

1937 ◽  
Vol 15c (6) ◽  
pp. 281-297 ◽  
Author(s):  
J. M. Armstrong
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
High Frequency ◽  
Somatic Chromosome ◽  
Poa Pratensis ◽  
Basic Chromosome Number ◽  
Somatic Chromosome Number ◽  
Indigenous Plants ◽  
Somatic Chromosome Numbers ◽  
Fibre Attachment

The somatic chromosome numbers of 20 species of Poa were determined. The basic chromosome number for the genus was found to be seven. The species arranged themselves in a polyploid series from diploid to dodecaploid, tetraploids and hexaploids being the most numerous. Three aneuploid species possessed chromosome numbers suggestive of a nonaploid origin. Polymorphism was found to be present in P. compressa L., P. palustris L. and P. nemoralis L. All species examined conformed to the long chromosome type common to the subfamily, Pooideae. The spindle fibre attachment for the chromosomes in the various species ideograms was found to be regularly median or submedian.The chromosome variability and the mode of seed production were examined in Poa pratensis L., using selected, uniform strains, indigenous plants and plants grown from commercial seed. The somatic chromosome number was found to range from 50 to 87 ± 1, 10 of the 19 plants examined possessing aneuploid numbers. The selected strains possessed the same chromosome number for both plants examined, while in the other material the number was variable. A study of meiosis in the P.M.C. showed the selected strains to vary from regular behavior to an irregularity of 3.9 unpaired univalents per cell. All strains possessed large percentages of morphologically good pollen which germinated actively on the stigmas. Reduction was observed in the E.M.C. of the selected strains and a study of the course of embryological development showed no irregularities which might lead to aposporous reproduction. A high frequency of polyembryony was observed which was correlated to the degree of irregularity at meiosis. A theory is advanced to explain how constant aneuploid numbers may be maintained in sexually reproduced strains.

scholarly journals Chromosome Numbers in 11 Species of Taraxacum Section Erythrosperma Dt. from Poland

2017 ◽  
Vol 59 (2) ◽  
pp. 77-82 ◽  
Author(s):  
Mateusz Marian Wolanin ◽  
Krystyna Musiał
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
First Time ◽  
Somatic Chromosome Numbers ◽  
Eleven Species

AbstractKaryology of eleven species of Taraxacum sect. Erythrosperma from Poland has been studied. Somatic chromosome numbers are given for the following species: T. bellicum, T. brachyglossum, T. cristatum, T. disseminatum, T. dissimile, T. lacistophyllum, T. parnassicum, T. plumbeum, T. proximum, T. scanicum, and T. tenuilobum. Although the hypertriploid chromosome number was previously reported in Poland for T. lacistophyllum, T. parnassicum, T. scanicum, and T. tenuilobum, we proved the triploid chromosome number 2n = 24 in all the species investigated, which is consistent with the data reported from other regions of Europe. The chromosome numbers of T. bellicum, T. cristatum, T. disseminatum, T. dissimile, T. plumbeum, and T. proximum growing in Poland are published for the first time.

AN EVALUATION OF THE STATUS OF CIRSIUM PUMILUM AND CIRSIUM HILLII

1966 ◽  
Vol 44 (5) ◽  
pp. 581-595 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
The Status ◽  
Somatic Chromosome Numbers

The specific separation of Cirsium hillii and C. pumilum has long been questioned. Their morphology, cytology, and distribution are discussed and it is concluded that two subspecies be recognized: C. pumilum (Nutt.) Spreng. ssp. pumilum and ssp. hillii (Canby) Moore & Frankton. The chromosome number of each subspecies is 2n = 30. Hybrids with the somatic chromosome numbers 31, 32 between ssp. pumilum (2n = 30) and C. horridulum Michx. (2n = 34) have been found in Massachusetts. It is suggested that introgression of C. horridulum into ssp. pumilum may be increasing variability of the latter.

scholarly journals Chromosome numbers in Begonia.

1969 ◽  
Vol 17 (3) ◽  
pp. 189-202 ◽  
Author(s):  
R.A.H. Legro ◽  
J. Doorenbos
Keyword(s):  
Chromosome Number ◽  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Polyploid Series ◽  
First Time ◽  
Somatic Chromosome Numbers

The somatic chromosome numbers of 100 Begonia species were counted, of which 72 have been determined for the first time. Eighteen different numbers have been established, ranging between 22 and 156, fifteen of which could be fitted into a tentative scheme of five polyploid series. The most common numbers were 22 (14 species), 28 (35 species) and 56 (17 species). The species have been grouped into sections according to Irmscher. In some cases these sections appeared to have a characteristic chromosome number whereas in others, e.g. Pritzelia and Begoniastrum, a great diversity in chromosome number was encountered. [For earlier work see H.A., 39: 5182.]-Univ. Wageningen. (Abstract retrieved from CAB Abstracts by CABI’s permission)

CHROMOSOME NUMBERS AND TAXONOMIC NOTES ON NORTHERN GRASSES: II. TRIBE FESTUCEAE

1960 ◽  
Vol 38 (2) ◽  
pp. 117-131 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Bromus Tectorum ◽  
Dactylis Glomerata ◽  
Bromus Inermis ◽  
Festuca Rubra ◽  
Lolium Rigidum ◽  
Voucher Specimens ◽  
Dactylis Glomerata L ◽  
Somatic Chromosome Numbers

Chromosome numbers and voucher specimens are recorded for some collections of the tribe FESTUCEAE Dumort., mainly collected in Canada. The somatic chromosome numbers of the following are recorded: (1a) Arctagrostis arundinacea (Trin.) Beal var. arundinacea, 2n = 28, 2n = 29, and 2n = 30; (1b) Arctagrostis arundinacea (Trin.) Beal var. crassispica Bowden, 2n = 56; (1c) Arctagrostis latifolia (R.Br.) Griseb., 2n = 56. (2) Beckmannia syzigachne (Steud.) Fern., 2n = 14. (3) Brachyelytrum erectum (Schreb.) Beauv., two vars., 2n = 22. (4a) Bromus ciliatus L., 2n = 14; (4b) Bromus inermis Leyss., two subspecies and two vars., 2n = 56; (4e) Bromus kalmii A. Gray, 2n = 14; (4d) Bromus porteri (Coult.) Nash, 2n = 14; (4c) Bromus tectorum L., 2n = 14. (5) Catabrosa aquatica (L.) Beauv. var. laurentiana Fern., 2n = 20. (6) Dactylis glomerata L., 2n = 28. (7) Distichlisstricta (Torr.) Rydb., 2n = 40. (8a) Dupontiafisheri R.Br, subsp. fisheri, 2n = 132; (8b) Dupontia fisheri R.Br, subsp. psilosantha (Rupr.) Hultén, 2n = 44. (9) Eremopoa persica (Trin.) Roshev., 2n = 28. (10a) Festuca altaica Trin., 2n = 28; (10b) Festuca baffinensis Polunin, 2n = 28; (10c) Festuca brachyphylla Schultes, 2n = 42 and one collection, 2n = 44; (10d) Festuca elatior L., 2n = 14; (10e) Festuca obtusa Bieler, 2n = 42; (10f) Festuca prolifera (Piper) Fern. var. lasiolepis Fern., 2n = 50; (10g) Festuca rubra L., 2n = 42; (10h) Festuca saximontana Rydb., 2n = 42; (10i)Festuca scabrella Torr. ex Hook., two vars., 2n = 56 and 2n = 28. (11a) Glyceria borealis (Nash) Batchelder, 2n = 20; (11b) Glyceria canadensis (Michx.) Trin., 2n = 60; (11c) Glyceria grandis S. Wats., 2n = 20; (11d) Glyceria melicaria (Michx.) Hubb., 2n = 40; (11e) Glyceria pulchella (Nash) K. Schum., 2n = 20; (11f) Glyceria striata (Lam.) Hitchc, 2n = 20; (11g) Glyceria × gatineauensis Bowden (G. melicaria × G. striata), 2n = 30; (11h)Glyceria × ottawensis Bowden (G. canadensis × G. striata), three nothomorphs, 2n = 42, 2n = 46, and 2n = 48. (12) Lolium rigidum Gaud., 2n = 14. (13a) Phippsiaalgida (Sol.) R.Br., 2n = 28; (13b) Phippsia concinna (Th. Fries) Lindeb., 2n = 28. (14) Pleuropogon sabinei R.Br., 2n = 42. (15) Schizachnepurpurascens (Torr.) Swallen, 2n = 20. (16) Torreyochloa fernaldii (Hitchc.) Church, 2n = 14.

scholarly journals Badania kariologiczne nad dwoma gatunkami rodzaju Sparganium L. [Karyological studies in two species of the genus Sparganium]

2015 ◽  
Vol 40 (1) ◽  
pp. 143-148
Author(s):  
K. Bijok ◽  
E. Adamkiewicz
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Somatic Chromosome Numbers

The somatic chromosome numbers 2n = 30 for <em>Sparganium neglectum</em> and <em>S. minimum</em> was established. The karyotype of the first species consist of 8 iso- and 7 heterobronchial chromosomes and the reverse is true for the second species. In metabolic nuclei 30 chromocentres are visible.

SOMATIC CHROMOSOME NUMBERS IN CERTAIN TRIFOLIUM SPECIES

1972 ◽  
Vol 14 (1) ◽  
pp. 139-145 ◽  
Author(s):  
M. K. Anderson ◽  
N. L. Taylor ◽  
G. B. Collins
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Karyotype Analyses ◽  
Somatic Chromosome Numbers

In the present study chromosome numbers of 13 Trifolium species were determined, making a total of 155 species for which chromosome numbers have been reported. Four species which have been reported only once were confirmed. Eleven of the 17 species observed have 16 chromosomes (n = 8). T. bocconei Savi was found to have 12 chromosomes (n = 6) and T. desvauxii Boess. and Bl. was found to have 10 chromosomes (n = 5). Karyotype analyses of T. bocconei and T. desvauxii revealed that the chromosomes of each species could be differentiated on the basis of arm ratios and chromosome lengths.

CHROMOSOME NUMBERS AND TAXONOMIC NOTES ON NORTHERN GRASSES: IV. TRIBE FESTUCEAE: POA, AND PUCCINELLIA

1961 ◽  
Vol 39 (1) ◽  
pp. 123-138 ◽  
Author(s):  
Wray M. Bowden
Keyword(s):  
Chromosome Numbers ◽  
Somatic Chromosome ◽  
Voucher Specimens ◽  
Somatic Chromosome Numbers

Chromosome numbers and voucher specimens are recorded for some Canadian and Alaskan collections and a few mainland American collections of Poa and Puccinellia which belong to the tribe FESTUCEAE. The somatic chromosome numbers of the following are recorded: (1) Poa agassizensis, 2n = ca. 56; P. alpina, 2n = 32, 33, 39, and 42; P. ampla, 2n = 62; P. annua, 2n = 28; P. arctica, 2n = 56, 63, 70, ca. 75, 78, 82, 85, 86, and 106; P. arida, 2n = ca. 76; P. canbyi, 2n = 56, 70, and ca. 98; P. cusickii, 2n = 56, and 59; P. eminens, 2n = 42; P. fernaldiana, 2n = ca. 42; P. glauca, 2n = 42, 50, 56, 64, 65, 70, 75, and 78; P. glaucantha, 2n = 44; P. glaucifolia, 2n = 56, ca. 70, and ca. 100; P. interior, 2n = 28, 34, 42, and 56; P. juncifolia, 2n = ca. 60; P. leptocoma, 2n = 42; P. nervosa, 2n = 56, and ca. 74; P. palustris, 2n = 28, 30, and 32; P. pratensis, 2n = 28, 42, 44, 56, ca. 66, 67, 70, 74, ca. 78, ca. 82, 84, 86, 88, and ca. 124; P. saltuensis, 2n = 28; P. secunda, 2n = 42, 56, 70, ca. 78, 80. and ca. 90; P. stenantha, 2n = 42; and P. trivialis, 2n = 14.(2) Puccinellia ambigua, 2n = 56; P. americana, 2n = ca. 42 and 56; P. angustata, 2n = 42; P. borealis, 2n = 42; P. bruggemannii, 2n = 28; P. cusickii, 2n = 28; P. distans, 2n = 42; P. glabra, 2n = 42 and 56; P. hauptiana, 2n = 28; P. laurentiana, 2n = 42 and 56; P.longiglumis, 2n = 56; P. lucida, 2n = 42 and 56; P. nuttalliana, 2n = 42; P. × phryganodes, 2n = 21; P. vaginata, 2n = 56; and P. vahliana, 2n = 14.

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