Karyological studies in Tripleurospermum (Asteraceae, Anthemideae) from north-east Anatolia

Chromosome number and morphology in 14 taxa belonging to 19 populations of Tripleurospermum Sch. Bip. were studied using karyological and numerical taxonomical techniques. Data on chromosome measurements were analysed using cluster analysis. Chromosome numbers of these taxa are 2 n  = 2 x  = 18, 4 x  = 36 and 5 x  = 42–48. Seven records are new, two are not consistent with previous counts, and the remainder confirm the very limited previous data (one to three records). A new ploidy level (pentaploidy) is reported for the first time for the genus. Some correlations between ploidy levels and morphological characters are noted and several systematic and evolutionary aspects of the genus are discussed in the light of karyological data.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 146 , 427–438.     

Chromosome variation in the genus Pinellia (Araceae) in China and Japan

The chromosome numbers of 23 populations belonging to seven species of Pinellia Tenore were counted. The basic chromosome number of all the species studied was x  = 13, and the previously reported basic numbers x  = 9 and x  = 14 in P. ternata and P. cordata were not confirmed. Chromosome numbers of 2 n  = 26 in P. polyphylla and 2 n  = 78 in P. integrifolia are reported for the first time. Heptaploid (7 x ) and nonuploid (9 x ) are new ploidy levels reported for P. ternata , and hexaploid for P. cordata. Taxonomic, phylogenetic and phytogeographical inferences are made for the genus. Particular attention was given to P. ternata , the most widely distributed species in the genus, and considerable variation of chromosome number was found in its different populations. Based on chromosome studies of 11 populations of P. ternata , together with 12 populations reported in previous studies, the lower reaches of the Yangze River are identified as its centre of origin. From there it dispersed, with generation of hexaploid, heptaploid, octoploid and nonuploid forms.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 449–455.     

Karyological notes on eight species of Achillea L. (Asteraceae, Santolinoideae) from Turkey

The chromosome number and morphology of eight species belonging to the section Santolinoideae of the genus Achillea L. (Asteraceae) were investigated using karyological techniques. The species studied were Achillea cucullata (Hausskn.) Bornm., A. vermicularis Trin., A. monocephala Boiss. & Bal., A. boissieri (Hausskn.) Bornm., A. santolina L., A. gypsicola Hub.-Mor., A. goniocephala Boiss. & Bal., and A. spinulifolia Fenzl ex Boiss. In these species, the chromosome numbers were 2 n  = 18 in A. vermicularis , A. monocephala , and A. boissieri , 2 n  = 18A + 1B in A. spinulifolia , 2 n  = 36 in A. cucullata and A. santolina , and 2 n  = 54 in A. gypsicola and A. goniocephala . All of the chromosomes had median point (M), median region (m), or submedian (sm) centromeres. An increase in asymmetry was not observed in the karyotypes of the species.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 573–580.     

First chromosome number determinations in south-eastern South American species of Lupinus L. (Leguminosae)

Chromosome numbers are presented for the first time for 30 accessions of nine south-eastern South American Lupinus species. Chromosome numbers of 2 n = 32 and 34 were found for L. bracteolaris (three out of five accessions with 2 n = 32) and L. linearis (two out of three accessions with 2 n = 32), and of 2 n = 36 for L. gibertianus , L. lanatus, L. magnistipulatus , L. multiflorus , L. rubriflorus , L. reitzii and L. uleanus . All the South American species examined have relatively low chromosome numbers when compared with most of the Old World and North American species. Our results, where 2 n = 36 is the rule, are in sharp contrast to the data for North American Lupinus species and reveal the following: (1) low chromosome numbers are the rule, at least in the southern part of eastern South America; (2) cytologically, the eastern South American species form a group distinct from the North American taxa; (3) high levels of polyploidy have not played as important a role in evolution and speciation in eastern South America as in North America; (4) the predominance of low chromosome numbers in eastern South American species and the existence of similar numbers in two of the six rough-seeded Old World species support the hypothesis that in the evolution of the genus the eastern South American species branched off first, followed by the rough-seeded group.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Socety , 2002, 139 , 395–400.     

New chromosome counts in the Centaurea Jacea group (Asteraceae, Cardueae) and some related taxa

Twenty-seven chromosome counts are reported in 23 species of the genus Centaurea , mostly eastern endemic species of the Jacea group, which has become the core of the re-defined genus Centaurea . Twenty reports are new, one is a correction of a previous count, one is a confirmation of limited previous data and one represents a new basic number in the Centaureinae. The prevalence of the basic chromosome number x  = 9 among the Eastern sections of the Jacea group is confirmed, together with the close correlation between karyological data and classification of the genus. Two alternative hypotheses on the aberrant chromosome number (for the Centaureinae) found in C. behen are proposed. One of them, if verified, would confirm that a cycle of polyploidy and descending dysploidy is a key mechanism in the speciation of the group.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 345–352.     

Karyomorphology of Incarvillea (Bignoniaceae) and its implications in distribution and taxonomy

The karyomorphology of 11 species of the genus Incarvillea Juss. is reported. The chromosome numbers of all species studied are 2 n  = 22. The interphase nuclei and prophase chromosomes were found to be of the simple chromocentre type and the interstitial type, respectively. The asymmetry of the karyotype of I. arguta (two populations) in subgenus Amphicome is type 2A. The karyotypes of Incarvillea s inensis var. sinensis , I.  s inensis var. przewalskii, and I. olgae in subgenus Incarvillea are of asymmetry type 3A. The remaining nine species and one variety in subgenus Pteroscleris are also of asymmetry 3A. Data on three species and one variety studied are first reports. This study indicates that karyotype variation at the diploid level appears to be the predominant feature of chromosome evolution in the genus Incarvillea . According to this study of karyomorphology, morphological characteristics and geographical distribution, it seems that the three subgenera should be regarded as three independent genera. The geography of the genus is discussed.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 113–121.     

Chromosome numbers in Brazilian species of Crotalaria (Leguminosae, Papilionoideae) and their taxonomic significance

Chromosome numbers were counted for 23 species of Crotalaria native to Brazil. Among these data there were new counts for 15 taxa, and some confirmed previous reports or represented numbers that were different from those cited previously. The chromosome numbers most frequently found were 2 n  = 16 and 2 n  = 32. Only C. incana L. had 2 n  = 14 and C. tweediana Benth. had 2 n  = 54. The counts 2 n  = 32 and 54 were found in species of section Calycinae and 2 n  = 16 and 14 in species of section Chrysocalycinae . The data revealed the importance of chromosomal parameters in the characterization of sections Calycinae and Chrysocalycinae in Brazil. We discuss the systematic significance and evolutionary aspects for the genus, comparing the results with the two sections that are native in Brazil.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 271–277.     

Chromosome number, karyotype, and taxonomic considerations on the enigmatic Sellocharis paradoxa Taubert (Leguminosae, Papilionoideae, Genisteae)

Until recently, Sellocharis paradoxa Taubert, the only species of this Genisteae genus, was known solely by the isotypes. Recent new collections in Rio Grande do Sul, southern Brazil, have enabled data on chromosome number and karyotype morphology to be obtained for the first time. S. paradoxa has 2 n  = 20 chromosomes, and a bimodal asymmetrical karyotype, composed of one pair of long ( c . 6.3 µm) metacentric, five pairs of shorter acrocentric, and four pairs of shorter telocentric chromosomes ranging from c . 3.7 to 2.7 µm. The chromosome number and karyotype morphology of S. paradoxa do not fit into the Genisteae pattern. Existing information is so far insufficient to answer evolutionary questions about its origin and phylogenetic relationships, but the uniqueness of this taxon, first indicated by its peculiar leaf arrangement, and now supported by its uncommon karyological constitution, strongly suggests that the suprageneric taxonomic position of S. paradoxa should be re-evaluated.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 223–226.     

Karyotype evolution in the genus Boronia (Rutaceae)

New chromosome counts are reported for Boronia clavata 2 n  = 14, B. heterophylla 'Near White' 2 n  = 15, B.  'Carousel' 2 n  = 16, B. deanei 2 n  = 22, B. chartacea 2 n  = 32, B. keysii 2 n  = 32, B. pilosa 2 n  = 44, B. anethifolia 2 n  = 36 and B. citriodora 2 n  = 108. Studies in 20 genotypes of 18 species and one interspecific hybrid revealed that they are highly complex in terms of chromosome number, ploidy level, chromosomal length, karyotype constitution and asymmetry. Karyotype analysis indicated that Boronia taxa with high chromosome numbers are primitive and those with lower numbers are derived. The basic chromosome number for this genus is suggested to be x = 18. Analysis of chromosome number, variations of total chromosome length (TCL) and average chromosome length (ACL), Nombre Fondamental (NF) and karyotype asymmetry suggest that dysploid reduction is the major mechanism in Boronia karyotype evolution. Chromosomal rearrangements might also have been involved. Origin, chromosome number changes and spread of Boronia are discussed in relation to the species divergence and the geological and climatic changes of the Australian continent.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 142 , 309–320.     

Cytotaxonomy of Begonia rubropunctata and B. purpureofolia (Begoniaceae)

The chromosome numbers of four Chinese Begonia species were counted for the first time as follows: 2 n  = 22 in B. rubropunctata , 2 n  = 18 in B. purpureofolia , 2 n  = 44 in B. pedatifida , and 2 n  = 22 in B. villifolia . The first two species had relatively large chromosomes with early condensed chromatin in the distal and interstitial or proximal regions, whereas the last two had small chromosomes with early condensed chromatin in the proximal regions. Although they have been reduced in the literature to synonyms of B. pedatifida and B. villifolia , respectively, B. rubropunctata and B. purpureofolia should be treated as distinct species because of the differences in chromosome numbers and other chromosome features.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 513–517.     

Chromosome study of the fern genus Cyrtomium (Dryopteridaceae)

Cyrtomium (Dryopteridaceae) is an Asiatic genus comprising about 40 species characterized by having anastomosing veins that form areolae with included veinlets. Twelve chromosome counts representing 11 taxa were made in the present study. The chromosome numbers of six species endemic to China are reported for the first time: C. uniseriale , 2 n  = 164; C. guizhouense , 2 n  = 82; C. shingianum , n  = 82, 2 n  =  c .164; C. chingianum , 2 n  = 164; C. urophyllum , 2 n  = 82 and C. aequibasis , 2 n  = 123. The results were used to show that (1) C. uniseriale should be reduced to varietal status under C. balansae ; (2) subseries Balansana is not closely related to any other Cyrtomium species and should be separated from Cyrtomium ; and (3) C. guizhouense and C. lonchitoides are basal groups when subseries Balansana is not considered. These results were also supported by morphology. A high level of differentiation is a distinct characteristic in Cyrtomium . The genus has two reproductive types: sexual and apogamous. Sexual species are distributed mostly in China. Southwestern China is a modern diversity centre of Cyrtomium , with 80.6% of known species occurring there. Many species are endemic, most of which are sexual tetraploids or apogamous triploids. Both the apogamous reproductive type and polyploid species are adaptions to limestone habitats.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 221–228.     

Chromosomal variability in the genus Primula (Primulaceae)

Chromosome numbers and measurements were recorded in 47 individuals of ten taxa of Primula , representing eight species and two subspecies from ten populations. The basic numbers of chromosomes were x  = 8, 9 or 11, and they were mostly metacentric, medium-long to medium-small, ranging in length from c . 3.6 µm to 1.6 µm. Diploid chromosome numbers of 2 n  = 2 x  = 24 and 22 were scored for the first time in P. loeseneri Kitag. and P. prenantha Balf. & Sm., respectively. A new ploidy level of 2 n  = 4 x  = 44 was found in P. burmanica Balf. & King. The recorded diploid numbers of the remaining species confirmed earlier reports. Interspecific variability in chromosome numbers was correlated with heterogeneity in their mean length. Comparison of the data with those in the literature revealed that the observed variability of chromosomal characters was compatible with the other taxonomic criteria and supports the current taxonomic delimitation. Chromosomal variation at the diploid level is the predominant feature in Primula evolution, and allopatric speciation has played a major role in its specific diversity. Subgen. Aleuritia could represent the main clade from which the other subgenera have evolved. The origin of the chromosome numbers, geographical distribution and evolution of the species were assessed, and the parallel polyphyletic mode of evolution in the genus was confirmed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 211–219.     

New chromosome counts in the genus Cousinia (Asteraceae) from Iran

Chromosome counts are reported of 38 populations representing 24 species of the genus Cousinia from Iran, one of the main centres of speciation of the genus. Sixteen of the counts are new to science. Our results confirm that Cousinia exhibits a complex dysploid series ranging from x  = 13 to x  = 9. One of the basic chromosome numbers, x  = 9, is new for the genus and must be confirmed. Some considerations on the correlation between chromosome numbers and section classification are made.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 411–419.     

Chromosomal criteria and their phylogenetic implications in the genus Onobrychis Mill. sect. Lophobrychis (Leguminosae), with special reference to Egyptian species

Chromosome numbers and measurements were recorded in 22 individuals from six populations of six species of Onobrychis , including the Egyptian species and most representatives of section Lophobrychis . The basic number of chromosomes was either x = 7 or x = 8 and the chromosomes were medium to medium-small, ranging in length, from c . 1.6 μm to 2.6 μm. Two new ploidy levels were found, 2 n = 4 x = 28 in O. bobrovii Grossh. and 2 n = 4 x = 32 in O. pulchella Schrenk. The origin of the chromosome numbers, geographical distribution and evolution of the species were assessed. Comparison of the data with those in the literature revealed that the observed interspecific variability among section Lophobrychis can be useful in taxonomic delimitation and demonstrates a complexity of evolution between the diploid and polyploid species. Section Lophobrychis has a comparatively highly derived organization and can be considered as a heterogeneous unit in the genus Onobrychis .  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 409–414.     

Chromosome counts in Asian Artemisia L. (Asteraceae) species: from diploids to the first report of the highest polyploid in the genus

This work comprises 24 reports of chromosome numbers in 24 Artemisia L. species from Asia. Ten are included in the subgenus Dracunculus Besser and the rest belong to other subgenera. Seven counts are new reports, 14 are consistent with scarce previous ones, and three contribute new ploidy levels. That carried out in A. medioxima reports the highest ploidy level ever counted for the genus (16 x ). There is only one species with x  = 8 as the basic chromosome number. In the remaining x  = 9-based species, ploidy levels range from 2 x to 16 x , illustrating the great role played by polyploidy in the evolution of the genus.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 301–310.     

A review of ploidy in the genus Prosopis (Leguminosae)

The genus Prosopis contains 44 species of trees and shrubs, the majority of which originate in the Americas. Most species are reported to be diploid, with a somatic chromosome number of 2 n  = 28. There are rare reports of polyploidy, although it is thought that these may represent polysomaty in root tissues. However, flow cytometry has recently indicated that P. juliflora is entirely tetraploid with a somatic chromosome number of 2 n  = 56. In order to clarify the situation, an extensive review of ploidy in Prosopis was undertaken, the first of its kind. The ploidy levels of 124 samples of Prosopis from 21 countries, including both the natural and introduced ranges, were analysed using flow cytometry. In addition, a comprehensive literature review was carried out, examining 305 published ploidy values and covering 32 of the 44 species of Prosopis . Flow cytometry analysis suggests that P. juliflora is the only tetraploid species, with a somatic chromosome number of 2 n  = 4 x  = 56, whilst the remainder of the species analysed are diploid with 2 n  = 2 x  = 28, including the first report for P. articulata (2 n  = 28). A critical review of published ploidy values shows that all species of Prosopis are reported to be entirely diploid, except P. glandulosa , P. juliflora , and P. koelziana , for which both diploid and tetraploid values have been recorded. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 156 , 425–438.     

Karyomorphology of the endangered Trigonobalanus doichangensis (A. Camus) Forman (Fagaceae) and its taxonomic and biogeographical implications

Cytological studies were carried out for the first time on five populations of Trigonobalanus doichangensis in China and Thailand. In all populations, the pattern of interphase nuclei was of the simple chromocentre type, the mitotic prophases were of the proximal interstitial type and chromosome numbers were 2 n  = 2 x  = 14. Two B chromosomes were commonly observed at prophase and prophase–metaphase, but rarely at metaphase. Karyotype variation among the populations at the diploid level was limited, but there were some distinguishing cytological characters. Based on the comparison of all the available data on cytology, taxonomy, phytogeography and molecular systematics related to the genus Trigonobalanus , we recommend that the three species of Trigonobalanus comprise the subfamily Trigonobalanoideae and that the genus should not be segregated into three monotypic genera.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 321–330.     

Systematic significance of cytology in Cyananthus (Campanulaceae) endemic to the Sino-Himalayan region

Chromosome numbers and the morphology of members of 24 populations representing 15 species of the Sino-Himalayan endemic genus Cyananthus(Campanulaceae) were studied using karyological and numerical taxonomic techniques. The chromosome numbers of these taxa are 2n = 10, 12, 14, 24, 28, and the basic chromosome numbers for the genus are x = 5, 6, 7. All species except C. inflatus Hook. f. & Thoms. and C. microphyllus Edgew. were examined for the first time and a new ploidy level (tetraploidy) is reported in the genus. Chromosome measurement data were analyzed using cluster analysis. The relationships between three sections within Cyananthus and evolutionary trends within the genus are discussed in the light of karyological data. The cytological data suggest that Cyananthus is a relatively primitive genus in Campanulaceae and there is significant division within the genus, and polyploidization may have played an important role in the chromosome evolution and speciation of Cyananthus in the Himalayan–Hengduan Mountains.     

A new spineless species of Vella (Brassicaceae) from the high mountains of south-eastern Spain

Vella castrilensis sp. nov. is described from the high mountains of Granada and Jaén provinces (south-eastern Iberian Peninsula), where it grows on calcareous soils. It is a hexaploid (2 n  = 68) spineless dwarf shrub, woody at the base, with oblong-lanceolate, entire to shallowly dentate leaves and fruit with an acute tongue-shaped stylar segment and strongly reticulate-nerved valves. The characteristic unique combination of vegetative, karyological and reproductive features of V. castrilensis is not present in any described taxon of the genus, and warrants recognition at the species rank. Affinities and differences with other related taxa are discussed. Phylogenetic, biogeographical, bioclimatic, ecological data and conservation proposals are also reported.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 121–128.