Karyological Studies in the Genus Androcymbium (Colchicaceae)

1999 ◽  
Vol 47 (1) ◽  
pp. 131 ◽  
Author(s):  
Marta Margelí ◽  
Joan Pedrola-Monfort ◽  
Joan Vallès Xirau

A karyological study was carried out in the genusAndrocymbium Willd. The karyotypes of 26 populationsbelonging to six species of the section Erythrostictus(Schldtl.) Benth. in Benth. & Hook.f. (included intheA. gramineum (Cav.) T.Macbr. group) and of onepopulation of a species of the section Androcymbium are established and themean results for each taxon are given. Chromosome counts from severalpopulations of all the species, the chromosome number ofA. eucomoides Willd., and most of the karyotypes arepresented here for the first time. A new basic number, x= 10, is also reported for the genus. On the basis of the dataobtained, a descendent dysploidy process in the evolution of the genus issuggested and the members of the A. gramineum group areconsidered to be schizoendemics.

2008 ◽  
Vol 33 ◽  
pp. 69-90 ◽  
Author(s):  
Eusebio LÓPEZ TIRADO ◽  
Juan Antonio Devesa

RESUMEN. Contribución al conocimiento cariológico del género Centaurea L. (Asteraceae) en laPenínsula Ibérica. Se da a conocer el número cromosómico de 22 táxones de Centaurea L. sect.Centaurea. En particular, se han estudiado 18 táxones del grupo de C. paniculata L., de los que C.paniculata subsp. exilis Arènes, C. paniculata subsp. geresensis Arènes, C. coutinhoi Franco, C.kheilii (Pau) Pau, C. limbata var. insularis Pau, C. castellanoides subsp. talaverae E. López & Devesa,C. cordubensis Font Quer, C. bethurica E. López & Devesa y C. schousboei Lange lo han sido porvez primera. Del grupo de C. alba L. se han estudiado 4 táxones, siendo nuevos los recuentos de C.costae Willk. var. costae y C. costae var. maluqueri Font Quer. En ambos grupos el número básicoencontrado ha sido x = 9. El número diploide 2n = 18 es el más frecuente mientras que el niveltetraploide 2n = 36(4x) sólo se ha detectado en C. aristata Hoffmanns. & Link, C. cordubensis FontQuer y C. schousboei Lange.Palabras clave. Asteraceae, Centaurea, número cromosómico, Península Ibérica.ABSTRACT. A contribution to the karyological knowledge of the genus Centaurea L. (Asteraceae)in the Iberian Peninsula. A karyological study of 22 taxa of genus Centaurea L. sect. Centaurea isreported. Within C. paniculata L. group we have studied 18 taxa and the reports for some of them aregiven for the first time: C. paniculata subsp. exilis Arènes, C. paniculata subsp. geresensis Arènes,C. coutinhoi Franco, C. kheilii (Pau) Pau, C. limbata var. insularis Pau, C. castellanoides subsp.talaverae E. López & Devesa, C. cordubensis Font Quer, C. bethurica E. López & Devesa and C.schousboei Lange. Within C. alba L. group we have studied the chromosome number of 4 taxa, butonly C. costae Willk. var. costae y C. costae var. maluqueri Font Quer are studied for the first time.In both groups we have found the basic number x = 9. Diploid number 2n = 18 is the most frequentwhereas tetraploid level 2n = 36(4x) has been found only in C. aristata Hoffmanns. & Link, C.cordubensis Font Quer and C. schousboei Lange.Key words. Asteraceae, Centaurea, chromosome number, Iberian Peninsula.


1934 ◽  
Vol 11 (2) ◽  
pp. 213-241 ◽  
Author(s):  
A. W. S. Hunter

The history and the present state of the classification of the Gramineae are briefly reviewed and a number of the different characteristics on which phylogenetic systems have been based are considered. The subjects of chromosome morphology and the application of idiograms and karyotypes to taxonomic studies are discussed. Avdulov's recently reported findings on the phylogeny of the grasses are summarized and compared with the results of other workers and those obtained in the present investigation. Three species of bamboos were studied for the first time and evidence secured to indicate that the basic number of the tribe is probably not 12 as has been elsewhere reported. In the Festuceae the chromosome number of Phragmites communis Trin. was definitely ascertained, confirming Avdulov's supposition that the basic number for the genus is 12. The other three species investigated agreed with the arrangement as proposed by Avdulov. The tribe Chlorideae, with the exception of the genus Beckmannia, has been reported to be almost entirely Panicoid with respect to chromosome morphology. This was confirmed in the four species examined. Avdulov's rearrangement of the tribe Hordeae was somewhat altered and a confusion m the nomenclature of the genus Lepturus was corrected. An anomalous situation was cleared up in the tribe Agrostideae by the establishment of the chromosome number of Sporobolus tennuissinus Kuntz as 40. The specimen of Anthoxanthum odoratum L. (tribe Phalarideae) examined provided a very interesting example of secondary splitting in somatic chromosomes. One species was examined in the tribe Melinideae and six in the tribe Paniceae. In the latter tribe no difference could be detected between the several subdivisions of the genus Panicum. The same condition held for the large genus Andropogon in the tribe Andropogoneae. In the tribe Maydeae the chromosome number of Tripsacum dactyloides L. was found to be 9, and the suggestion was made that it may be a link, along with the genus Coix, between the Andropogoneae and the Maydeae. The other four species examined all had a basic number of 10.


Phytotaxa ◽  
2019 ◽  
Vol 416 (4) ◽  
pp. 278-286
Author(s):  
MOHAMED OWIS BADRY ◽  
JENNIFER A. TATE ◽  
PRASHANT JOSHI ◽  
AHMED MAHMOUD ABBAS ◽  
SOHAIR THABET HAMED ◽  
...  

A taxonomic revision of Hibiscus trionum from Egypt was undertaken using morphological and cytological studies of field collections and herbarium specimens. The data indicate that all specimens so far collected in Egypt belong to H. tridactylites, rather than H. trionum. This paper includes a comprehensive description of H. tridactylites, its occurrence, a comparison with other species in the H. trionum complex, and comments on habitat, along with images for easy identification. In addition, chromosome counts for this species from Egypt have been determined for the first time, which add to existing information on chromosome counts for the species from different regions of the world.


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.


2019 ◽  
Vol 6 (2) ◽  
pp. 147-150
Author(s):  
Chiranjit Paul ◽  
Bimal Debnath

Chromosomal study conducted in nine species of Dioscorea from different forest belts of Tripura revealed that their somatic chromosome number ranged from 2n=40 to 2n=60. The record of 2n=40 chromosome in the sexual phenotypes of Dioscorea hamiltonii, Dioscorea glabra and Dioscorea pubera are the first time report from Tripura, North East India. Moreover the somatic chromosome counts of 2n=60 in Dioscorea pentaphylla would be attributed as a new cytotype. However at the respective ploidy level no difference in somatic chromosome count was observed between their sexes.


2020 ◽  
Vol 45 (4) ◽  
pp. 873-878
Author(s):  
Juan D. Urdampilleta ◽  
Eliana R. Forni-Martins ◽  
María S. Ferrucci

Abstract—Chromosome counts from 23 populations of 16 species of Paullinia (Paullinieae, Sapindaceae) from South America are given. These include first counts for ten species in six of the thirteen sections of this genus. Counts of 2n = 24 for P. cristata, P. revoluta, P. thalictrifolia, P. trigonia, P. uloptera, P. rhomboidea; 2n = 48 for P. seminuda and P. sp.; and two cytotypes of 2n = 48 and 2n = 96 for P. carpopoda and P. rubiginosa; and ca. 2n = 216 for P. cupana var. sorbilis. The chromosome number 2n = 24 appears to be conserved for this genus, however, in this contribution polyploid series are cited for the first time for some native species. These results were interpreted in a phylogenetic context.


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.


2000 ◽  
Vol 14 (1) ◽  
pp. 11-24
Author(s):  
Ladislau A. Skorupa

Chromosome counts for eight species of Pilocarpus Vahl (Rutaceae) a native of Brazil are reported for the first time. Chromosome numbers were determined from mitotic root tip cells of seedlings derived from field collections and grown in the greenhouse. Feulgen staining was used. Initial pre-treatment of root tips was done by using a saturated aqueous solution of alpha-bromonapthalene for two hours at room temperature (20-25ºC). Chromosome numbers of 2n=44 and 2n=88 were determined for the examined taxa. The present results suggest the occurrence of tetraploidy in P. spicatus St.-Hil. and P. carajaensis Skorupa, and a possible basic number x=22 to the genus Pilocarpus.


1969 ◽  
Vol 47 (8) ◽  
pp. 1257-1275 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton

The morphology and chromosome number of nine species of Cirsium of eastern North America are considered. Chromosome counts are presented for the first time for C. iowense, 2n = 18; C. lecontei, 2n = 32; C. nuttallii, 2n = 24, 28; C. repandum, 2n = 30; C. smallii, 2n = 34; C. engelmannii, 2n = 20; C. texanum, 2n = 22, 24; C. virginianum, 2n = 28. Additional chromosomes, possibly to be considered as accessories, were found in C. nuttallii, C. engelmannii, and C. texanum. These chromosomes render uncertain the number characteristic of these species. A key to the 26 native and introduced species found in Canada and the United States east of 100° west latitude is presented. The interrelationships of the eastern species and of the species of the western series Undulata are discussed.


1954 ◽  
Vol 32 (1) ◽  
pp. 182-186 ◽  
Author(s):  
R. J. Moore ◽  
C. Frankton

The chromosome numbers of three introduced species of Centaurea are here reported: C. diffusa Lam., 2n = 18; C. maculosa, Lam., 2n = 36; C. repens L., 2n = 26. The chromosome counts of C. diffusa and of C. maculosa, which are here reported for the first time, help to clarify a taxonomic problem. A pappus is usually lacking on the achenes of C. diffusa but is present on those of C. maculosa. As a result, plants of C. diffusa with a short pappus have been considered to be possible hybrids between these species. Three such plants here studied had the diploid chromosome number 18, rather than the triploid number to be expected in such a hybrid. Examination of pollen of suspected hybrid specimens shows that the percentage of normal pollen is high. This fact also supports the belief that plants of C. diffusa with a short pappus on the achene are not hybrids with C. maculosa.


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