Chromosome numbers, meiotic behavior, and notes on tropical American grasses (Gramineae)

1974 ◽  
Vol 52 (2) ◽  
pp. 317-328 ◽  
Author(s):  
Gerrit Davidse ◽  
Richard W. Pohl

Chromosome numbers and meiotic behavior are reported for 126 collections of grasses representing 50 genera and 111 species. First counts are given for the genera Leptothrium, n = 10, and Cryptochloa, 2n = 22 (somatic count). First chromosome counts are given for the following 25 species: Aristida recurvata, n = 11; Axonopus laxus, n = 20; Chloris mollis, n = 20; Chusquea longifolia, n = 20; Cryptochloa concinna, 2n = 22; Digitaria abyssinica, n = 18; Eragrostis airoides, n = 36; E. guianensis, n = 10; Eriochloa boxiana, n = 18; Gymnopogon foliosus, n = 10; Leptothrium rigidum, n = 10; Luziola pittieri, n = 12; L. spruceana, n = 24; Otachyrium inaequale, n = 10; Panicum cayennense, n = 27; P. chloroticiun, n = 18; P. schiffneri, n = 18; Pappophorum pappiferum, n = 30; Paspalum apiculatum, n = 10; P. arundinaceum, n = 30; P. contractum, n = 9; P. coryphaeum, n = 30; P. trachycoleon, n = 20; Setaria barbata, n = 27; and Trisetum foliosum, n = 28. Counts that differ from previously reported counts are given for the following 15 species: Axonopus chrysoblepharis, n = 10; Cenchrus brownii, n = 34; Digitaria horizontalis, n = 9, 27; Echinolaena gracilis, n = 10; Euclasta condylotricha, n = 10; Hyperthelia dissoluta, n = ca. 30; Ischaemum guianense, n = 18; Microchloa indica, n = 12; Paspalum candidum, n = 10; P. melanospermum, n = 20; P. prostratum, n = 10; Rhytachne rottboellioides, n = 16; Setaria paniculifera, n = 16; Sorghastrum incompletum, n = 20; and Thrasya petrosa, n = 30. Changes in nomenclature are indicated for Digitaria species whose chromosome numbers were reported in our earlier publications.

1972 ◽  
Vol 50 (7) ◽  
pp. 1441-1452 ◽  
Author(s):  
Gerrit Davidse ◽  
Richard W. Pohl

Chromosome numbers and meiotic behavior are reported for 99 collections of grasses representing 47 genera and 88 species. First chromosome counts are reported for the following 20 species: Aristida laxa, n = 22; Chloris ekmanii, n = 20; Chusquea scandens, n = 20; Danthonia domingensis, n = 18; Eragrostis hypnoides, n = 10; E. prolifera, n = 20; Festuca mirabilis, n = 14; Leptochloa scabra, n = 30; Manisuris ramosa, n = 18; Paspalum carinatnm, n = 40; P. distortum, n = 10; Pharus glaber, n = 12; Raddia sympodica, 2n = 22; Raddiella nana, n = 10; Schizachyrium gracile, n = 20; Setaria crus-ardeae, n = 18; Thrasya paspaloides, n = 20; Trachypogon ligularis, n = 10; Trichachne laxa, n = 18; Tristachya avenacea, n = 24. The count for Raddiella nana represents a first generic report. Counts that differ from previous counts for the same taxon are reported for these 11 species: Andropogon gerardii, n = 40; Aristida orizabensis, n = 22; Eragrostis trichocolea, n = 30; Ichnanthus nemoralis, n = 10; Microchloa kunthii, n = 22; Olyra latifolia, n = 22; Panicum cyanescens, n = 27; Paspalum caespitosum, n = 10; P. millegrana, n = 20, 30; Schizachyrium hirtiflorum, n = 20; Trachypogon montufari, n = 30.


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.


1992 ◽  
Vol 5 (4) ◽  
pp. 501 ◽  
Author(s):  
HM Stace ◽  
JA Armstrong

Chromosome counts for 30 taxa, representing five genera, are reported for Rutaceae subfamily Rutoideae, mostly in the Australasian tribe Boronieae. We found n = 10 for Boronia algida which is previously unreported in the genus, and a sterile triploid taxon in Zieria. Generic chromosome numbers of n = 18 in Zieria, n = 16 in Phebalium and n = 14 in Eriostemon sens. lat. occur, while Boronia shows cytoevolution on n = 18, 11, 10, 9. Pollen sterility and possible apomixis is indicated in some species. Some taxonomic implications of cytological data in the tribe Boronieae are discussed.


1974 ◽  
Vol 52 (5) ◽  
pp. 923-925 ◽  
Author(s):  
Allan R. Beck ◽  
Jack L. Weigle ◽  
Eric W. Kruger

Impatiens crosses were made among the following: P.I. 349629 (Java), P.I. 349586 (New Guinea), I. Itolstii, and "Tangerine." All crosses were successful except those made with I. Itolstii. Chromosome counts were as follows: P.I. 349629 = 16, P.I. 349586 = 32, I. Itolstii = 16, and "Tangerine" = 8. Chromosome counts of the hybrids were midway between the respective parents. Cytological studies indicated a similarity in chromosome morphology and size among all parents except I. holslii. A new genome count of 4 is reported for the genus Impatiens indicating a ploidy series in which x = 4.


2012 ◽  
Vol 69 (2) ◽  
pp. 323-345 ◽  
Author(s):  
F. Christie ◽  
S. Barber ◽  
M. Möller

Chromosome numbers were determined in 23 accessions representing 21 species hitherto belonging toChirita(Gesneriaceae), a genus that has recently been remodelled and split into five different genera:Damrongia,Henckelia,Liebigia,MicrochiritaandPrimulina. The previously monotypicPrimulina tabacumwas also investigated. Counts for 19 species were new, two were confirmatory and two gave different numbers from previously published counts. The results here, together with previously published cytological data for the erstwhile genusChirita, were analysed in the light of the taxonomic revision of the genus and published phylogenetic data.Chiritawas originally highly heterogeneous in chromosome numbers, including seven different somatic numbers, 2n= 8, 18, 20, 28, 32, 34 and 36. Among the five remodelled genera,Henckeliawas found to be as equally heterogeneous as the erstwhileChirita,Microchiritaincluded only two chromosome numbers, 2n= 18 and 34, the three species ofDamrongiawere uniform with 2n= 18, while species belonging to the extendedPrimulinashowed only one basic number,x= 18, with 15 samples being diploid, and one being tetraploid. In the light of recent phylogenetic studies, polyploid as well as dysploid changes appear to have shaped the genomes of the newly defined generaHenckelia,Microchiritaand, to a lesser degree,Primulina.


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.


1964 ◽  
Vol 42 (10) ◽  
pp. 1387-1391 ◽  
Author(s):  
R. J. Moore ◽  
J. A. Calder

Chromosome counts of 36 taxa and two hybrids of Carex are presented: 18 are new, 11 verify previous counts, 5 differ by 2 from previous counts, and 2 differ more widely from reported counts. Taxonomic notes relating to a few species arc included.


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.


HortScience ◽  
1990 ◽  
Vol 25 (12) ◽  
pp. 1646-1647 ◽  
Author(s):  
A. Estilai ◽  
A. Hashemi ◽  
K. Truman

Edible chia seeds, purchased from the local markets in Guatemala, Mexico, and southern California, were used for species identification, chromosome counts, karyotype construction, and meiotic analyses. Plants raised from those seeds had ovate leaves, dense racemose inflorescences, pale-blue flowers, and were identified from herbarium specimens as Salvia hispanica L. Mitotic analyses of root tips from 50 plants showed 2n = 12—the lowest chromosome number in the genus. Chromosomes were small, ranging from 2 to 3.5 pm. One pair of chromosomes was metacentric (with the long arm: short arm ratio, r = 1.5), four pairs were submetacentric (r = 2.6 to 3.6), and one pair was telocentric (r = 12). Meiosis was regular and six bivalents were observed at metaphase I. Ring and rod bivalents averaged 1.53 ± 1.05 and 4.47 ± 1.05, respectively;


Author(s):  
Seher Güven ◽  
Serdar Makbul ◽  
Kamil Coşkunçelebì

We report chromosome counts for ten taxa of Vincetoxicum sensu stricto (s. str.) (Apocynaceae) from Turkey (of which two are endemic), including the first chromosome counts for V. canescens subsp. pedunculata, V. funebre, V. fuscatum subsp. boissieri, V. parviflorum and V. tmoleum. Two taxa of V. fuscatum proved to be tetraploid (2n=44) and the remaining eight taxa diploid (2n=22). Molecular phylogenetic analyses based on nrDNA (ITS) and cpDNA (trnT-trnL) (including 31 newly generated sequences) confirm the position of the Turkish Vincetoxicum in the Vincetoxicum s. str. clade. Vincetoxicum fuscatum, V. parviflorum, V. speciosum, as well as the Turkish endemic V. fuscatum subsp. boissieri, were clearly resolved as species-level clades, whereas the delimitation of the rest of the Turkish taxa was less clear based on molecular data.


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