Karyological observations on plant taxa endemic to the Balearic Islands

Mitotic chromosome numbers are reported from 35 vascular plant taxa endemic to the Balearic Islands that are poorly known cytogenetically. The chromosome numbers of Chaenorhinum rodriguezii (2 n  = 14), Coristospermum huteri (2 n  = 22), Carduus ibicensis (2 n  = 26), Filago petro-ianii (2 n  = 26), Ononis crispa ssp. zschackei (2 n  = 30), and Ophrys bertolonii ssp. balearica (2 n  = 36) were determined for the first time. New chromosome numbers are reported in Pimpinella bicknellii (2 n  = 22), Calamintha rouyana (2 n  = 46), Vicia bifoliolata (2 n  = 14), and Teucrium asiaticum (2 n  = 30). A new diploid cytotype (2 n  = 16) was found in Ranunculus paludosus ssp. barceloi , which is restricted to populations from the western Balearics (Eivissa and Formentera), whereas tetraploid plants are known from the eastern Balearics (Mallorca). It is suggested that the tetraploid cytotype arose from the diploid cytotype through autopolyploidy. The idiograms of Coristospermum huteri , Pastinaca lucida , Pimpinella bicknellii , Carduus ibicensis , Helianthemum scopulicolum , Helichrysum crassifolium , Vicia bifoliolata , p aeonia cambessedesii , Helleborus lividus , Ranunculus paludosus ssp. barceloi , and Linaria aeruginea ssp. pruinosa are determined for the first time.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 463–476.     

Karyological studies on the Sino-Himalayan endemic Soroseris and two related genera of tribe Lactuceae (Asteraceae)

Karyological studies were carried out on ten populations comprising six species of Soroseris in the tribe Lactuceae (Asteraceae), all endemic to the alpine Sino-Himalayan region and poorly known cytogenetically. The single species of Stebbinsia (one population) and two species of Syncalathium (three populations) were also examined for the first time. The basic chromosome number for the three genera is x  = 8. Stebbinsia and most species of Soroseris are diploids with 2 n  = 2 x  = 16 = 14m + 2sm and have a karyotype asymmetry type 1A. Three species of Soroseris are tetraploid (2 n  = 4 x  = 32 = 28m + 4sm). A karyotype of 2 n  = 2 x  = 16 = 14m(2SAT) + 2sm with type 1A asymmetry was found in Syncalathium kawaguchii , and of 2 n  = 2 x  = 16 = 6m + 10sm with type 2A asymmetry for two populations of Syncalathium souliei . The relationships between Soroseris and the other two genera are discussed. Our cytological results suggest that polyploidy plays a minor role in the chromosome evolution of plants from the Himalayan mountains and adjacent regions.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 154 , 79–87.     

Occurrence of tetraploid and octoploid cytotypes in Senecio jacobaea ssp. jacobaea (Asteraceae) in Pannonia and the Carpathians

Four different cytotypes have been reported for Senecio jacobaea L. ssp. jacobaea throughout Europe, with the most common occurrence of tetraploids (2 n  = 40). Here we present a survey of previously published chromosome number data on this subspecies and its geographical distribution, and focus on populations from Pannonia and the Carpathians. Two ploidy levels have been determined in the study area, using chromosome counting and flow cytometry: tetraploid (2 n  = 40) and octoploid (2 n  = 80). Fifty-one populations originating from Slovakia, Austria, the Czech Republic, Hungary, Ukraine and Romania have been analysed. Multivariate morphometric analyses have been performed on 39 populations to study morphological differentiation between these two cytotypes. Despite slight morphological tendencies expressed on the level of populations, tetraploid and octoploids cannot be reliably distinguished morphologically and they are not taxonomically classified formally here.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 153 , 231–242.     

Cytogenetics of species of Chamaecrista (Leguminosae – Caesalpinioideae) native to southern Brazil

Chromosome numbers, karyotypes, meiotic behaviour and pollen analysis are presented for species of Chamaecrista Moench (Leguminosae, Caesalpinioideae, Cassieae ) native to southern Brazil: C. nictitans ssp. patellaria , C. nictitans ssp. disadena , C. repens , C. rotundifolia , C. flexuosa , C. vestita and C. desvauxii . Meiotic behaviour is reported for the first time for all the taxa and was very regular; only bivalents were formed at diakinesis and metaphase I, chromosome disjunction and segregation were regular at anaphases I and II, meiotic indexes were over 99% and pollen fertility was over 92%. Pollen grains were subprolate in C. flexuosa and C. vestita and prolate–spheroidal in the other taxa. Karyotypes were symmetrical in all six species and the data are original, except for C. nictitans ssp. p atellaria. Chromosome number is presented for the first time for C. repens (2 n  = 16) and has been confirmed for the other taxa: 2 n  = 14 for C. desvauxii , 2 n  = 32 for the tetraploid C. nictitans ssp. patellaria and C. nictitans ssp. disadena , and 2 n  = 16 for the other species. These two basic numbers found in the genus, x  = 7 and x  = 8, point to chromosome evolution by dysploidy, which has also been accompanied by polyploidy.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 429–439.     

Chromosome numbers in plant taxa endemic to the Balearic Islands

Mitotic chromosome numbers are reported from 20 vascular plant taxa that are endemic to the Balearic Islands and poorly known cytogenetically. The chromosome numbers of Arenaria grandiflora L. ssp. glabrescens (Willk.) G. López & Nieto Feliner (2 n  = 44), Dianthus rupicola Viv. ssp. bocchoriana L. Llorens & Gradaille (2 n  = 30), Solenopsis minuta (L.) C. Presl. ssp. balearica (E. Wimm.) Meikle (2 n  = 28), Romulea asumptionis Font Quer & Garcías Font (2 n  = 56), Scutellaria balearica Barceló (2 n  = 22) and Galium balearicum Briq. (2 n  = 22) have been determined for the first time. A new chromosome number was found in two populations of Helictotrichon crassifolium (Font Quer) Holub (2 n  =  c. 98) suggesting that this species is a high polyploid (14 x ), in contrast to an earlier report of a lower chromosome count (2 n  = 12 x  = 84). Cytogenetic observations suggest that Naufraga balearica Constance & Cannon has a diploid chromosome complement of 2 n  = 20, with 0–2 accessory chromosomes. The banded karyotype (chromomycin A₃) of Crepis triasii (Cambess.) Fries was determined for individuals belonging to eight populations from three islands. Two chromomycin A₃-positive regions were recorded in the diploid complement. These are present on the telomeric regions of the shortest subtelocentric chromosomes. This species is karyologically stable in chromosome number, karyotype and fluorochrome-banding pattern among populations from separate islands.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 219–228.     

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.     

Cytological studies on the Sino-Himalayan endemic Anisodus and four related genera from the tribe Hyoscyameae (Solanaceae) and their systematic and evolutionary implications

Cytological studies were carried out on eight species of five genera ( Anisodus , Atropanthe , Hyoscyamus , Mandragora and Przewalskia ) in the tribe Hyoscyameae (Solanaceae). First chromosome counts were reported in six species: Anisodus luridus , A. acutangulus , A. tanguticus , A. carniolicoides , Atropanthe sinensis and Mandragora caulescens , all with 2 n  = 8 x  = 48. Two records, for Hyoscyamus niger (2 n  = 2 x  = 34) and Przewalskia tangutica (2 n  = 4 x  = 44), were also confirmed. All species studied showed the proximal type of mitotic prophase chromosome condensation pattern. Three types of interphase nuclei were recognized: the round prochromosome type for Anisodus , Atropanthe and Mandragora , the rod prochromosome type for Przewalskia and the complex chromocentre type for Hyoscyamus . The cytological data supported the close relationship of all four species of Anisodus . Evidence from the interphase nuclei and chromosome base numbers supported the traditional classification of Hyoscyameae into two groups, i.e. Physochlaina praealta + Hyoscyamus (complex interphase type and x  = 7, 14, 17) and Przewalskia + Atropanthe + Anisodus + Scopolia + Atropa + Mandragora (prochromosome type and x  = 6, 11). Polyploidy is found in most species of the tribe in the Himalayan–Hengduan Mountains, as well as in the Mediterranean region, west–central Asia and eastern Asia. It seems that it probably occurred very early in Hyoscyameae evolution, before the uplift of the Himalayan–Hengduan Mountains. The Himalayan orogeny might have played a minor role in the polyploid evolution of plants in this tribe.  © 2005 The Linnean Society of London. Botanical Journal of the Linnean Society , 2005, 147 , 457–468.     

Natural hybridization in Cardamine (Brassicaceae) in the Pyrenees: evidence from morphological and molecular data

While researching Cardamine (Brassicaceae) in the Pyrenees, putative hybrid plants were found at two natural sites. Pollen grain viability, AFLP, and multivariate morphometric analyses were performed in order to assess the plants' presumed hybrid origin, establishing that natural hybridization between the diploids C. crassifolia and C. amara ssp. pyrenaea had occurred. A new diploid nothospecies, C. × enriquei (2 n = 2x = 16), is described. Examination of 18 morphological characters showed the intermediacy of the hybrid between the parental taxa in most characters. AFLP analyses of C. amara ssp. amara , ssp. austriaca , ssp. olotensis and C. raphanifolia , demonstrated the close position of the hybrid to C. crassifolia , and revealed that the highest number of markers were shared with the parents. Polymorphism found in the AFLP pattern of the hybrid suggested recurrent origin, segregation and/or backcrosses, although assessment of pollen viability indicated high male sterility. The hybridization event reported here represents the second documented case between the C. pratensis group and C. amara . An account of the nomenclature of C. crassifolia is also presented, including lectotypification of relevant names.  © 2002 The Linnean Society of London, Botanical Journal of the Linnean Society , 2002, 139 , 275–294.     

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.     

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.     

Reduction of chromosome number in Eleocharis subarticulata (Cyperaceae) by multiple translocations

Eleocharis subarticulata is recorded as the third species of Cyperaceae with a reduced chromosome number ( n  = 3), following reports on Rhynchospora tenuis ( n  = 2) and Fimbristylis umbellaris ( n  = 3). For Eleocharis, the numbers recorded to date vary from 2 n  = 10 to 2 n  = c. 196, with x  = 5 as the possible basic number. The karyotype of E. subarticulata was studied using conventional staining (mitosis and meiosis), C-CMA₃/DAPI banding, and FISH with 45S rDNA and telomere probes. The chromosomes showed no primary constrictions, as expected in the holocentric chromosomes of Cyperaceae. The meiotic behaviour was abnormal, with a single multivalent ring of six chromosomes at metaphase I, resulting from multiple translocations. At anaphase I six chromatids migrated to each pole, evidencing the inverted meiosis, and these groups were also visible at metaphase II. The C-CMA₃/DAPI banding technique showed only four terminal GC-rich blocks. FISH with 45S rDNA probes revealed four terminal signals, probably associated with GC-rich blocks. The telomeric probe located terminal signals in all the chromosomes, besides a hybridization site in the middle of the large pair. The occurrence of ectopic telomeric sites has not been described previously for plants with holokinetic karyotypes and with reduced chromosome numbers. These data reinforce the hypothesis of the reduction in chromosome number by multiple translocations.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 457–464.     

Karyotype analysis in South American species of Myrtaceae

In Myrtaceae (Myrteae), the diploid chromosome number 2 n  = 2 x  = 22 is the most common, although variations of ploidy level occur, with some triploid (2 n  = 3 x  = 33) and tetraploid (2 n  = 4 x  = 44) records. Karyotype details in this group are scarce because the chromosomes are small (< 2 μm). In this work, we carried out a karyotypic analysis of 15 species of Myrtaceae grouped in different subtribes and genera. Measurements of chromosome length (long arm, L ; short arm, S ) were taken and several karyotypic parameters were calculated for each species. The karyotypes in fleshy-fruited taxa (Myrteae) were more varied than in the other previously analysed dry-fruited group ( Eucalyptus , Eucalypteae), in which the chromosomes were exclusively metacentric.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society, 2007, 155 , 571–580.     

Karyological and taxonomic notes on Ophrys (Orchidoideae, Orchidaceae) from the Iberian Peninsula

Karyological information on Iberian Ophrys species is very limited. This paper provides the haploid and diploid chromosome numbers of 11 taxa of sect. Pseudophrys and sect. Ophrys , both of which are well represented in the Iberian Peninsula, and two taxa from Tunisia. The first data on chromosome numbers for O. vasconica (2 n  = 72, 74), O. ficalhoana (2 n  = 36), O. picta (2 n  = 36), O. sphegifera ( n  = 18, 2 n  = 36, 38) and O. passionis (2 n  = 36) are also presented, confirming the stability of the chromosome number in Ophrys . In addition, populations of the group O. omegaifera ( O. dyris and O. vasconica ), together with tetraploidy, pentaploidy and the existence of aneuploid phenomena, are reported for the first time in Iberia. The basic diploid number is always 2 n  = 36. The karyotypes of several species were analysed. Evolutionary trends in Ophrys chromosomes are discussed. Taxonomic and phytogeographical details are provided on several species or groups of species from Iberia.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society, 2003 , 142 , 395−406.     

Cytotaxonomy of Lychnophoriopsis Sch.Bip. and Paralychnophora MacLeish species (Asteraceae: Vernonieae: Lychnophorinae)

The genera Lychnophoriopsis and Paralychnophora are endemic to Brazilian 'campo rupestre' in the States of Minas Gerais and Bahia. To analyse the status of the cytotaxonomy of these genera, we carried out chromosome counts on several species. Two chromosome numbers were obtained for four species of Paralychnophora : 2 n  = 36 and 2 n  = 38. For three species of Lychnophoriopsis , only 2 n  = 36 was observed. The chromosome size (1.0–2.58 µm) and morphology (mainly metacentric, with some submetacentric) were analysed in four species of Paralychnophora and showed relative constancy .   © 2007 The Linnean Society of London. Botanical Journal of the Linnean Society , 2007, 154 , 109–114.     

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.     

Karyotype differentiation between Koelreuteria bipinnata and K. elegans ssp. formosana (Sapindaceae) based on chromosome banding patterns

Koelreuteria Laxm., a genus in the tribe Koelreuterieae (Sapindaceae), includes three tree species that are widely recognized as having horticultural merit. The two more closely related species, K. bipinnata Franch. and K. elegans (Seem.) A. C. Sm., are easily distinguished from K. paniculata Laxm. by their bipinnate leaves. In this study, both species were investigated cytogenetically and their karyotypes and heterochromatic patterns were compared. Koelreuteria bipinnata and K. elegans ssp. formosana (Hayata) F. G. Mey. both have 2 n  = 32 but their karyotypes present slight morphological differences when observed using conventional staining. Chromosome banding patterns are reported for the first time for this genus. Both species exhibit terminal heterochromatic blocks, as revealed by C-Giemsa and C-CMA₃, but the band size varies between the species. Koelreuteria bipinnata has larger heterochromatic blocks and more GC-rich segments, while in K. elegans ssp. formosana these bands are smaller. The relationship between the karyotype features in these closely related species is discussed.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 451–455.     

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.