Karyotaxonomy of Greek serpentine angiosperms

The chromosome numbers are given for 20 angiosperm taxa, most of which grow predominately or exclusively on serpentine in Greece, and the karyotype morphology is illustrated in all cases but one. Chromosome data are provided for the first time for ten taxa ( Alyssum pogonocarpum, Centaurea charrellii, C. vlachorum, Cephalaria fanourii, Matricaria tempskyana, Onosma stridii, Scorzonera doriae, Silene fabarioides, S. salamandra, Trinia glauca ssp. pindica ) and for the endemic monospecific genus Leptoplax . A new number is reported for Thymus teucrioides ssp. candilicus . An unexpected dysploid number is recorded for a population of Leontodon hispidus ssp. hispidus. Chromosome number and karyotype details from Greek populations are presented for the rest of the taxa. Chromosomal evidence supports close relationships among members of Onosma subsect. Asterotricha . The unusual chromosome number of Centaurea vlachorum supports its placement either in C. sect. Jacea or C . sect. Cyanus . The evolution of taxa in sections Vierhapperia, Pulvinares , and Nervosae of Scorzonera appears to be connected with particular chromosomal rearrangements and dysploidy. Leptoplax does not share the same chromosome number with Peltaria but with Bornmuellera instead, something that facilitates infrageneric hybridization. Further issues of taxonomy, distribution, evolution and conservation of serpentine species are briefly discussed where appropriate. © 2002 The Linnean Society of London , Botanical Journal of the Linnean Society , 2002, 139 , 109–124.     

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 new species of Centaurea (sect. Phalolepis, Compositae: Cardueae) from eastern Peloponnisos, Greece

A new species of Centaurea L. , Centaurea leonidia Kalpoutz. & Constantin. , from two localities west and south-west of the town of Leonidio in eastern Peloponnisos, Greece, is described and illustrated. It belongs to C . sect. Phalolepis , and taxonomically its closest relatives are C. heldreichii Halácsy , a very localized species from south-west Sterea Ellas (Greece) and, surprisingly, C. niederi Heldr., which belongs to sect. Acrolophus. The new species is currently known from two populations of less than 100 individuals each, growing on almost inaccessible cliffs close to the convent of Agios Nikolaos Sintzas (St. Nicolas of Sintza) and the slopes of Poundes summit. Several other Greek endemic species are found in the same areas. Centaurea leonidia is scientifically important as it belongs to a small group of taxa, which, although they are members of sect. Phalolepis , have close allies in sect. Acrolophus. The chromosome number of C. leonidia , 2 n  = 18, counted in root tips, is also reported and illustrated.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 146 , 375–383.     

New or rarely reported chromosome numbers in taxa of subtribe Artemisiinae (Anthemideae, Asteraceae) from Mongolia

This study encompasses 25 chromosome counts of 18 species in the subtribe Artemisiinae (tribe Anthemideae) of the family Asteraceae, from Mongolia. Most (15 species) belong to Artemisia , the largest genus of the subtribe, whereas the others come from two genera very closely related to it: Ajania (two species) and Neopallasia (one species). Eleven counts are new reports, three are not consistent with previous reports and the remainder confirm scanty earlier information. The majority of the species have x  = 9 as their basic chromosome number, but there are some taxa with x  = 8. Ploidy levels range from 2 x to 6 x . The presence of B-chromosomes was detected in Ajania fruticulosa .  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 203–210.     

Chromosome numbers in the tribes Anthemideae and Inuleae (Asteraceae)

Twenty-two chromosome counts of 19 taxa (21 populations) in the tribe Anthemideae and one member (one population) of the tribe Inuleae of the family Asteraceae are reported. The Anthemideae studied belong to the subtribes Artemisiinae (14 Artemisia taxa, and one species each of the genera Dendranthema , Filifolium and Neopallasia ) and Tanacetinae (one species each of the genera Lepidolopha and Tanacetopsis ). From the Inuleae, we studied one Inula species. Five counts are new reports (including two at generic level), six are not consistent with previous counts and the remainder are confirmations of very limited (one to four records) previous data. Most of populations of Anthemideae studied have the basic chromosome number x  = 9, with ploidy levels ranging from 2 x to 10 x . Dysploidy is also present, with two x  = 8 diploid taxa. The species of Inuleae studied is a diploid with x  = 10, also indicating dysploidy, other members of the same genus Inula having basic numbers of x  = 9 or 8.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 148 , 77–85.     

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.     

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.     

Contribution to the karyological knowledge of Echinops (Asteraceae, Cardueae) and related genera

Twenty-six chromosome counts were made of several genera of the tribe Cardueae from various European and Asian provenances: Acantholepis (one species studied), Amphoricarpus (1), Chardinia (1), Echinops (14 species, 15 populations), Siebera (1), Staehelina (3) and Xeranthemum (4). Eleven of the reports are made for the first time, ten confirm previous counts, while the remainder report disparities with earlier records. The existence of different basic chromosome numbers and ploidy levels suggests dysploidy and polyploidy as the main mechanisms of chromosomal evolution in the taxa considered.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 145 , 337−344.     

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 the tribe Anthemideae (Asteraceae) from north-east Anatolia

Twenty-two chromosome counts of 19 taxa in the tribe Anthemideae of the family Asteraceae are reported from north-east Anatolia, Turkey. The taxa belong to the subtribes Achilleinae (four Achillea taxa), Anthemidinae (five Anthemis taxa), Artemisiinae (two Artemisia species), Leucantheminae (one Lecanthemum species), Matricariinae (two Tripleurospermum species) and Tanacetinae (five Tanacetum taxa). Six counts are new reports, seven are not consistent with previous counts, and the remainder are confirmations of very limited previous data. Most of the populations of Anthemideae studied have the basic number x  = 9, with ploidy levels ranging from 2 x to 7 to 8 x , but dysploidy is also present, with one diploid species, Artemisia austriaca , having x  = 8.  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 153 , 203–211.     

Pollen studies in subtribe Centaureinae (Asteraceae): the Jacea group analysed with electron microscopy

Although it has been recognized for many years that the genus Centaurea L. is an artificial assemblage of taxa, its partition into more natural affiliations has been impossible due to its incredible complexity. One of the most reliable characteristics for establishing the phylogeny within this group is the type of pollen. Most of the classification difficulties centre in the Jacea group, which has a characteristic Jacea pollen type. Recent molecular studies indicate that this assemblage is probably polyphyletic. Specifically, previous DNA sequence analyses indicate that Centaurea pulchella and the genera Oligochaeta and Zoegea represent different lineages. This finding prompted an investigation of their pollen types, using scanning electron microscopy, and for some species, transmission microscopy. For a rigorous comparison, the study also included a wide representation of other species across the entire Jacea group. Results showed that both Oligochaeta and Zoegea , but not C. pulchella , can be clearly distinguished from the Jacea group on the basis of pollen morphology. The genus Oligochaeta has a peculiar pollen type that may represent a simplified form of the Serratula pollen type, and the genus Zoegea has Serratula pollen type.     

Uniformity of karyotypes in Ligularia (Asteraceae: Senecioneae), a highly diversified genus of the eastern Qinghai–Tibet Plateau highlands and adjacent areas

Ligularia , a highly diversified genus in the eastern Qinghai–Tibet Plateau and adjacent areas, was chosen as a suitable subject in which to study speciation patterns in this 'hot spot' area at the chromosomal level. Chromosome numbers and karyotypes were studied in 23 populations of 14 species, most of which are endemic to this area. The basic number x  = 29 was confirmed for all species. Ligularia virgaurea was found to have diploid and triploid cytotypes, 2 n  = 58 and 87. Other species are only diploid, with 2 n  = 58. The karyotypes of all populations within any species, and all species spanning most sections and covering most of the morphological range in Ligularia , are very similar to each other, belonging to type 2A according to Stebbin's classification. This karyotype was also found in its close allies, e.g. Cremanthodium , Ligulariopsis , Parasenecio , and Sinacalia . Aneuploid reduction of chromosome number from 2 n  = 60 to 58 and karyotypic variation was found in Ligularia and its allies. Such a chromosomal pattern with few polyploids infers that variation of karyotype structure at the diploid level seems to be the predominant feature of chromosomal evolution in this group and sympatric speciation via hybridization and polyploidization has played a minor role in its species diversity.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 329–342.     

Chromosomal studies in species of Salvia (Lamiaceae) from Argentina

Meiotic and mitotic chromosomes of 13 species of Salvia from Argentina were studied. Most of our data are new counts but some, mainly from cultivated species, confirm previous reports or represent numbers which are different from those cited previously. Only Salvia gilliesii Benth. and the introduced species S. coccinea Juss., S. farinacea Benth., S. involucrata Cav. and S. microphylla Kunth are diploids. S. cardiophylla Benth., S. procurrens Benth. , S. splendens Roem. & Schult. and S. uliginosa Benth. are tetraploids; S. stachydifolia Benth. is hexaploid; and S. guaranitica A. St.-Hil., S. pallida Benth. and S. rypara Briq. are octoploids. The basic number most frequently found is x  = 11, but two species, S. procurrens and S. uliginosa , have x  = 13. S. farinacea has x  = 10 but this species is a widespread cultivated plant, not native in this area. Seven of the studied species showed one to three B chromosomes. We discuss some systematic and evolutionary aspects of the genus in the light of the cytogenetic data, the relationships between geographical distribution and chromosome numbers in relation to levels of ploidy and basic chromosome numbers, and make comparisons with some of the different taxonomic sections.  © 2003 The Linnean Society of London, Botanical Journal of the Linnean Society , 2003, 141 , 483–490.     

The cytology of Actinidia, Saurauia and Clematoclethra (Actinidiaceae)

Meiosis and mitosis of six Chinese Actinidiaceae were studied: Saurauia tristyla DC., S. miniata C. F. Liang & Y. S. Wang, Actinidia chinensis Plach., A. deliciosa (Cheval.) C. F. Liang & A. R. Ferguson, A. indochinensis Merr. and Clematoclethra lasioclada Maxim. The chromosome numbers of Saurauia tristyla and S. miniata were 2 n  = 6 x  = 78, establishing a base chromosome number of x  = 13 in the genus, differing from the previous report of x  = 15. The chromosome number of Clematoclethra was first reported to be 2 n  = 4 x  = 48 ( x  = 12), while that of Actinidia was x  = 29, consistent with previous reports. The base chromosome number of Clematoclethra ( x  = 12) was derived from an aneuploid decrease from Saurauia ( x  = 13). Actinidia (x  = 29) was derived from the palaeotetraploid ( x  = 14), which was formed through the increase of the basic chromosome number x  = 13 to x  = 14 by aneuploidy and through the breakage of a centromere to add one more new chromosome. The chromosome data in Actinidia were consistent with the geographical and morphological evidence for the evolution of the three genera. The tropical American and Asian disjunct distribution pattern and the diversity of base chromosome numbers of Saurauia further support the probability that the genus was an early divergent from a common ancestor of Actinidia and Clematoclethra .  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 369–374.     

Satellite-DNA evolutionary patterns under a complex evolutionary scenario: the case of Acrolophus subgroup (Centaurea L., Compositae) from the western Mediterranean

Within the genus Centaurea (subtribe Centaureinae, tribe Cardueae, Compositae) hybridizations and reticulate-evolution phenomena have widely been recognized. This is especially true in the taxa included in the subgroup Acrolophus from the western Mediterranean area, in which recurrent hybridizations of parapatric ("microallopatric") lineages within the geographical range of a primary radiation have been suggested. The subgroup Acrolophus includes taxa from three sections (i.e. Acrolophus, Phalolepis and Willkommia), and, together with other subgroups, forms the named Jacea group (one of the three main groups into which Centaurea is divided). In this paper, we have studied the influence that the complex evolutionary scenario described for the Acrolophus subgroup from the western Mediterranean exerts on the evolutionary pattern of a satellite-DNA family, the HinfI family, which exists within the genomes of these taxa. To this end, we have analyzed the evolution of this satellite-DNA family in taxa from different taxonomic comparative levels: i) seven subspecies of the C. boissieri complex (one of which with two varieties) of the sect. Willkommia; ii) species of the sections Willkommia (10 species, 19 taxa), Acrolophus (two species), and Phalolepis (two species), all in the Acrolophus subgroup; iii) one external species to the Jacea group, C. granatensis from the group Acrocentron; iv) and species from other related genera from the Centaureinae subtribe (Phonus and Carthamus, both belonging to the Carthamus group). The influence of the suggested model for the origin and diversification of the Acrolophus subgroup is evidenced by the existence of three different HinfI satellite-DNA subfamilies coexisting in some genomes, and by the analysis that we have made by comparing site-by-site the transition stages in the process of concerted evolution between the sequences of the each subfamily. From this analysis, we can deduce that the HinfI repeated subfamilies evolved in a gradual manner, and that the different stages of concerted evolution fit quite well with the combined nuclear-chloroplast-DNA-deduced divergences and phylogeny of the subtribe Centaureinae. The HinfI satellite-DNA from the Carthamus species group (genera Carthamus and Phonus) and from the Acrocentron group (Centaurea granatensis) shows a high intraspecific conservation of the repeats, suggesting that the mechanisms producing concerted evolution have been efficient in these taxa. In addition, the comparison of individual nucleotide positions between related species shows a paucity in the spreading of variants in each subfamily with satellite-DNA divergence, an indication of a constant rate of homogenization of the repeated cluster. On the contrary, this trend is absent in the comparisons of the HinfI sequences from taxa of the subgroup Acrolophus. In this subgroup, we have found in this repetitive family similar representative average sequences for each taxon analyzed, polymorphic sites in each taxon being scant, most of them autapomorphic, representing early stages of genetic differentiation between taxa in the process of concerted evolution. The absence of concerted evolution was visualized by similar levels of intraspecific variation and interspecific divergence and by the lack of fixed species-diagnostic nucleotide sites. These facts might reflect the reticulate mode of evolution of Acrolophus.     

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.