scholarly journals Chromosome Numbers of Four Nigerian Species of Cola Schott. & Endlicher (Sterculiaceae).

2005 ◽  
Vol 54 (1-6) ◽  
pp. 42-44 ◽  
Author(s):  
P. O. Adebola ◽  
J. A. Morakinyo

Abstract This paper reports the results of chromosome countings in four wild Cola species (Cola lateritia, C. ballayi, C. verticillata and C. gigantea). Cytological investigation of these species gave a constant mitotic chromosome counts of 2n = 4x = 40 for the first time. The karyotypes were found to consist mostly of metacentric and submetacentric chromosomes. In addition to confirming the chromosome numbers and ploidy levels in these species, the results also reveals high symmetry and homogeneity of the karyotypes with those of the cultivated species (C. nitida and C. acuminata) already reported. The similarity in chromosome morphology between the cultivated and wild species indicate their common origin and suggests the possibility of using these wild species as bridges for gene transfer in Cola breeding programmes involving interspecific hybridization.

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.


Turczaninowia ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 83-88
Author(s):  
Zohreh Babaee ◽  
Maryam Norouzi ◽  
Samaneh Mosaferi ◽  
Maryam Keshavarzi

Cirsium Mill. contains more than 250 species in the world mainly distributed in the Northern hemisphere. Different chromosome numbers with different ploidy levels were reported in this genus. In this study, karyotype details and chromosome numbers were established for two Cirsium taxa in Iran. C. ciliatum subsp. szovitsii and C. echinus had the mitotic chromosome numbers of 2n = 2x = 34. Karyotype analyses showed that chromosomes were generally metacentric and sub-metacentric. In C. echinus, Lowshan population had the longest chromosome (19.10 µm) and Heyran Canyon population (4.73 µm) the shortest one while in C. ciliatum, the longest chromosome was observed in Urmia to Salmas population (14.67 µm) and the shortest one (4.71 µm) in Doshanlu population. Total haploid chromosome length ranged from 275.29 to 376.42 µm in populations studied. Both taxa were grouped in 2B class. B-chromosomes were recorded for two taxa studied too. Chromosome type, mitotic chromosome numbers and occurrence of B-chromosomes were in agreement with previous results (Albers, Pröbsting, 1998; Lövkvist, Hultgård, 1999; Yüksel et al., 2013; Yildiz et al., 2016).


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.


2002 ◽  
Vol 15 (6) ◽  
pp. 839 ◽  
Author(s):  
Mary D. Tindale ◽  
S. K. Roy

A cytotaxonomic survey of the ferns and fern allies of Australia (including Lord Howe Island) is presented. Five-hundred-and-twenty-six chromosome counts of 268 Australian species, subspecies, varieties, variants and hybrids are recorded, only a small number having been previously investigated by other botanists on Australian material. Diploids represent c. 62% of the counts on species and c. 38% on polyploids, the latter ranging principally from triploids to a single decaploid and dodecaploid (but no heptaploids). More than one ploidy level has been reported in 19 taxa (almost 8% of taxa). Counts of 10x for Asplenium aethiopicum and 12x for A.�flabellifolium are the highest definite ploidy levels for the Australian pteridophyte flora. Chromosome counts for 29 families and 89 genera are cited. Only diploids were reported for Osmundaceae and Cyatheaceae, but only polyploids for the Psilotaceae, Vittariaceae and Ophioglossaceae. An analysis is given of the levels of ploidy in 248 taxa, excluding the Lycopodiaceae and Hymenophyllaceae. The percentages of diploids and polyploids in Australian species are compared with those of nearby countries. Many species reported on here have never been cytologically investigated before, while others have not been studied previously on Australian material. The following genera have been examined cytologically for the first time: Coveniella Tindale, n = 41; Paraceterach (F.Muell.) Copel., n = 29; 'Oenotrichia Copel.', 2n = 82 (2x); Revwattsia (Watts) D.L.Jones, 2n = c. 328 (8x); and Pteridoblechnum Hennipman (2n = 54). The phylogeny of the genera is discussed in the light of these findings. Certain families such as the Adiantaceae, Cyatheaceae, Hymenophyllaceae, Lindsaeaceae and Marsileaceae were given special attention by collecting as much living material as possible. A number of species-complexes has been found and further chromosome counts added to intercontinental species complexes. The Döpp-Manton and Braithwaite forms of reproductive apomixis have been reported amongst some genera. Endemism, hybridity and apogamy amongst Australian pteridophytes are discussed, as well as homosporous and heterosporous species. The new combination Phymatosorus membranifolius (R.Br.) Tindale is made.


Author(s):  
O. Yu. Yurkevich ◽  
T. E. Samatadze ◽  
I. Yu. Selyutina ◽  
S. A. Zoshchuk ◽  
A. V. Amosova ◽  
...  

For the first time, a comparative karyotype analysis of closely related species Hedysarum gmelinii andH. setigerum (Hedysarum section Multicaulia) grown in Southern Siberia, has been performed by molecular cytogeneticmarkers. Chromosome numbers in karyotypes of these species were specified – 2n = 4х = 32. In some accessions, additionalB chromosomes were revealed. FISH analyses indicated high similarities in chromosome morphology and also patternsof chromosomal distributions of 45S and 5S rDNA clusters in karyotypes of H. gmelinii and H. setigerum, which confirmsthe close relationship between their genomes.


Caryologia ◽  
2021 ◽  
Vol 74 (1) ◽  
pp. 53-61
Author(s):  
Maryam Hasaninejad ◽  
Ziba Jamzad ◽  
Saeid Afsharzadeh ◽  
HojJatollah Saeidi

In this survey, the chromosome counts of eight Nepeta L. species were investigated and the karyotypic diversity among these species was studied. The examined species belong to N. cephalotes Boiss. species group, namely N. eremokosmos Rech.f., N. gloeocephala Rech. f., cephalotes Boiss., N. pungens (Bunge) Benth., N. ispahanica Boiss., N. mahanensis Jamzad & Simonds, N. hormozganica Jamzad and N. denudata Benth. collected from different habitats in Iran. The ploidy levels, karyotype formula, chromosome length range, total karyotype length, several karyotype asymmetries values and Stebbins classification were determined in this study. Results showed the same chromosome number, 2n = 2x= 18 for all studied species. The basic chromosome number for the above mentioned species are x = 9. Also, the smallest chromosome length is 1.02 μm in N. mahanensis. The largest chromosome length is 2.3 μm in N. ispahanica. The chromosomes of species were metacentric or submetacentric. According to the Stebbins classification, these species were located into three classes 1A, 2A and 3A. The chromosome numbers for six of studied species are reported here for the first time.


2008 ◽  
Vol 21 (6) ◽  
pp. 443 ◽  
Author(s):  
Lachlan M. Copeland ◽  
Jeremy J. Bruhl ◽  
Lyn A. Craven ◽  
Curt L. Brubaker

Diploid chromosome counts are reported for the first time for 23 species of Homoranthus (Myrtaceae) and published counts are confirmed for a further three species. H. wilhelmii (F.Muell.) Cheel was determined as having 2n = 14, which contrasts with an earlier report of n = 6 for the species. Dysploidy appears to be common within the genus, with diploid chromosome numbers of 2n = 14, 16, 18 and 20 being recorded. There was no evidence of recent polyploidy within Homoranthus nor of any infraspecific dysploidy. Chromosome numbers appear to be a useful taxonomic tool to confirm the distinctness of some morphologically similar taxa but may be of limited use in estimating phylogenetic relationships.


HortScience ◽  
2017 ◽  
Vol 52 (7) ◽  
pp. 1029-1032 ◽  
Author(s):  
Jason D. Lattier ◽  
Hsuan Chen ◽  
Ryan N. Contreras

Chromosome numbers are an important botanical character for multiple fields of plant sciences, from plant breeding and genetics to systematics and taxonomy. Accurate chromosome counts in root tips of woody plants are often limited by their small, friable roots with numerous, small chromosomes. Current hydrolysis and enzyme digestion techniques require handling of roots before the root squash. However, optimum chromosome spread occurs when the cell walls have degraded past the point of easy handling. Here, we present a new enzyme digestion protocol that is fast, efficient, and flexible. This protocol reduces handling of the roots allowing for long-duration enzyme digestion. Digestions are performed on a microscope slide, eliminating the need for handling digested cells with forceps or pipettes. To illustrate the flexibility of this method across woody plant taxa, we performed chromosome counts on five angiosperms and one gymnosperm. Ploidy levels included diploids, triploids, and tetraploids with chromosome numbers ranging from 2n = 16 to 2n = 80. The range of holoploid 2C genome sizes spanned 1.54–24.71 pg. This protocol will provide a useful technique for plant cytologists working with taxa that exhibit a wide range of genome size and ploidy levels.


1968 ◽  
Vol 46 (12) ◽  
pp. 1513-1522 ◽  
Author(s):  
R. J. Moore

Chromosome counts for 17 species of Caragana are given. The chromosome numbers of the following species are reported for the first time: C. ussuriensis, 2n = 48, and C. brevifolia, C. maximowicziana, C. pleiophylla, C. conferta, C. tangutica, C. pekinensis, all 2n = 16. Remarks on the taxonomy of some species are presented. Cytology and morphology, as related to phylogeny of the genus, are discussed and a scheme of the evolution of Caragana is advanced.


2018 ◽  
Vol 12 (3) ◽  
pp. 403-420 ◽  
Author(s):  
Petra Macháčková ◽  
Ľuboš Majeský ◽  
Michal Hroneš ◽  
Eva Hřibová ◽  
Bohumil Trávníček ◽  
...  

The species-rich and widespread genusTaraxacumF. H. Wiggers, 1780 (Asteraceae subfamily Cichorioideae) is one of the most taxonomically complex plant genera in the world, mainly due to its combination of different sexual and asexual reproduction strategies. Polyploidy is usually confined to apomictic microspecies, varying from 3x to 6x (rarely 10x). In this study, we focused on Taraxacum sect.Taraxacum(= T.sect.Ruderalia;T.officinalegroup), i.e., the largest group within the genus. We counted chromosome numbers and measured the DNA content for species sampled in Central Europe, mainly in Czechia. The chromosome number of the 28 species (T.aberransHagendijk, Soest & Zevenbergen, 1974,T.atrovirideŠtěpánek & Trávníček, 2008,T.atroxKirschner & Štěpánek, 1997,T.baeckiiformeSahlin, 1971,T.chrysophaenumRailonsala, 1957,T.coartatumG.E. Haglund, 1942,T.corynodesG.E. Haglund, 1943,T.crassumH. Øllgaard & Trávníček, 2003,T.deltoidifronsH. Øllgaard, 2003,T.diastematicumMarklund, 1940,T.gesticulansH. Øllgaard, 1978,T.glossodonSonck & H. Øllgaard, 1999,T.guttigestansH. Øllgaard in Kirschner & Štěpánek, 1992,T.huelphersianumG.E. Haglund, 1935,T.ingensPalmgren, 1910,T.jugiferumH. Øllgaard, 2003,T.laticordatumMarklund, 1938,T.lojoenseH. Lindberg, 1944 (=T.debrayiHagendijk, Soest & Zevenbergen, 1972,T.lippertianumSahlin, 1979),T.lucidifronsTrávníček, ineditus,T.obtusifronsMarklund, 1938,T.ochrochlorumG.E. Haglund, 1942,T.ohlseniiG.E. Haglund, 1936,T.perdubiumTrávníček, ineditus,T.praestabileRailonsala, 1962,T.sepulcrilobumTrávníček, ineditus,T.sertatumKirschner, H. Øllgaard & Štěpánek, 1997,T.subhuelphersianumM.P. Christiansen, 1971,T.valensMarklund, 1938) is 2n = 3x = 24. The DNA content ranged from 2C = 2.60 pg (T.atrox) to 2C = 2.86 pg (T.perdubium), with an average value of 2C = 2.72 pg. Chromosome numbers are reported for the first time for 26 species (all butT.diastematicumandT.obtusifrons), and genome size estimates for 26 species are now published for the first time.


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