Molecular cytogenetics of <Emphasis Type="Italic">Bellevalia</Emphasis> (Hyacinthaceae) species occurring in Greece

Eight taxa of the genus Bellevalia (Hyacinthaceae) occurring in Greece, all with basic chromosome number x = 4, were cytologically studied using classical and molecular-cytogenetic techniques [fluorochrome banding with chromomycin A₃, fluorescence in situ hybridization (FISH) using probes of 18S–5.8S–26S and 5S ribosomal RNA genes]. Two of the examined taxa are endemic, i.e., B. brevipedicellata and B. sitiaca, both restricted to the Island of Kriti. B. hyacinthoides and B. edirnensis are Balkan endemics, and the four remaining taxa, i.e., B. dubia subsp. boissieri, B. trifoliata, B. romana, and B. ciliata, are more widely distributed Mediterranean elements. Genome size, estimated by flow cytometry, ranged from 18.59 to 53.38 pg. The results of fluorochrome banding and FISH are reported for the first time for the genus Bellevalia. Despite the morphological similarity of the chromosome complement, which is in accordance with the general “basic” Bellevalia karyotype formula, the karyotypes of the studied species are clearly distinguished by the number and position of GC-rich bands and ribosomal DNA (rDNA) loci, revealing clear interspecific differentiation among the taxa. Additionally, examination of the polyploid species B. sitiaca and B. edirnensis and populations of B. hyacinthoides and B. ciliata with different ploidy levels permits discussion about the origin of polyploids and the taxonomic relationships among the taxa.     

Karyotype analysis and new chromosome number reports in <Emphasis Type="Italic">Silene</Emphasis> species (sect. <Emphasis Type="Italic">Auriculatae</Emphasis>, Caryophyllaceae)

Karyotype study was performed in 13 populations of 11 Silene species (sect. Auriculatae L., Caryophyllaceae) growing in Iran. All the species studied showed 2n = 2x = 24 chromosome number supporting the earlier report on S. meyeri, while the chromosome number of S. palinotricha, S. sojakii, S. gertraudiae, S. elymaitica, S. pseudonurensis, S. dschuparensis, S. eriocalycina, S. araratica, S. prilipkoana and S. commelinifolia are new to science. The chromosomes were mainly metacentric or sub-metacentric and their size varied from 1.10 μm in S. pseudonurensis to 7.11 μm in S. dschuparensis. The species studied differed significantly in the total size of the chromosomes, the size of the short arms and the long arms, indicating the role of quantitative genomic changes in the Silene species diversification. They also differ in their karyotype formulae indicating the occurrence of structural changes in their chromosomes. The Silene species were placed in 1A, 2A, 1B and 2B classes of Stebbins karyotype symmetry showing symmetrical karyotypes. Clustering of the species based on karyotype features grouped the species of S. palinotricha, S. prilipkoana, S. commelinifolia, S. eriocalycina, S. meyeri, S. araratica and S. Sojakii together while the species of S. gertraudiae and S. elymaitica showed more similarity and were placed close to each other.     

Chromosomal features and evolution of Bromeliaceae

New cytological information and chromosome counts are presented for 19 taxa of 15 genera of the Bromeliaceae, among them, data for 15 taxa and five genera are reported for the first time. The basic number x = 25 is confirmed and polyploidy seems to be the main evolutionary mechanism in Bromeliaceae. Most of the analyzed species presented 2n = 50. Polyploids have been detected in Deinacanthon urbanianum with 2n = ca.160 and Bromelia laciniosa with 2n = ca.150. In Deuterocohnia lorentziana we observed individuals with two different ploidy levels (2n = 50 and 2n = 100) growing together in the same pot. Ayensua uaipanensis showed the uncommon number 2n = 46. After triple staining with CMA₃/Actinomycin/DAPI one or two CMA⁺/DAPI⁻ bands could be observed in the studied species (Aechmea bromeliifolia, Greigia sphacelata and Ochagavia litoralis). The role of these features in the evolution of the family is discussed, revealing new aspects of the evolution of the Bromeliaceae.     

CHROMOSOME NUMBERS IN UMBELLIFERAE. III

Chromosome numbers are reported for 156 collections representing 100 taxa of Umbelliferae. Approximately two thirds of the collections are from Mexico, Central and South America and indicate a high percentage of polyploid species in certain genera found in this area. Chromosome numbers for plants belonging to 78 taxa are published here for the first time, previously published chromosome numbers are verified for 18 taxa and chromosome numbers differing from those previously published are reported in seven instances. No chromosome counts have been previously published for nine of the genera included here. Further aneuploidy and polyploidy were found in Eryngium, and Lomatium columbianum has been found to be a high polyploid with 2n = 14x. Every chromosome count is referable to a cited herbarium specimen.     

Karyomorphology and nuclear DNA content of sixteen Ophrys L. taxa from Turkey

Karyotypes in 16 representative taxa of the Ophrys genus are compared, based on Feulgen-stained somatic metaphase chromosomes. The karyotypes of O. omegaifera subsp. israelitica, O. ulupinara, O. lycia, O. argolica subsp. lucis, O. argolica subsp. lesbis, O. climacis and O. reinholdii subsp. reinholdii are described for the first time. Karyological analyses indicate relationships among the species with respect to their asymmetry indices. All Ophrys taxa studied were diploid with 2n = 2x = 36 chromosomes. One B chromosome has been detected among the chromosomes of O. argolica subsp. lucis. All karyotypes are symmetrical, consisting of metacentric and submetacentric chromosomes. The longest chromosomes of all the investigated specimens contain a secondary constriction. It is determined that there is a correlation between the total number of chromosomes having secondary constrictions and the evolutionary development order of the taxa. Based on nuclear DNA content, analysis was carried out by flow cytometer using propodium iodide as fluorochrome, 2C nuclear DNA content of 16 Ophrys species varying between 20.80 pg (O. argolica subsp. lucis) and 23.11 pg (O. omegaifera subsp. israelitica). Karyotype asymmetry relationships are discussed according to the bidimensional scatter plots of A₁–A₂, CV_CL–CV_CI, CV_CL–M_CA and CV_CI–M_CA.     

Extreme degree of chromosome number variability in species of the spider genus Scytodes (Araneae, Haplogynae, Scytodidae)

Genus Scytodes includes most species of the spider family Scytodidae. Until now, 187 species of the genus have been described. In spite of this great diversity, only three Scytodes species were karyotyped so far. The present paper provides for the first time karyotype analysis of two synanthropic species, Scytodes fusca and Scytodes itapevi. Furthermore, new data on karyotype of Scytodes globula are also provided using conventional and differential cytogenetical procedures. The diploid number in the genus Scytodes varied considerably, namely from 2n = 13 to 2n = 31. The diploid number found in S. globula (2n♂ = 13) is the lowest in haplogyne spiders with monocentric chromosomes. Except S. globula, this number has been found only in one haplogyne spider with monocentric chromosomes, namely Ochyrocera sp. (Ochyroceratidae). On the contrary, the diploid number of S. fusca (2n♂ = 31) is one of the highest diploid numbers recorded in haplogyne spiders. The degree of intrageneric variation found in the genus Scytodes is the highest recorded in araneomorph spiders with monocentric chromosomes so far. Some karyotype characteristics (diploid number, chromosome morphology, total chromosome length, and distribution of constitutive heterochromatin) allowed us to postulate a close relationship between S. globula and S. itapevi. According to the karyotype data, S. fusca is not closely related to these two species. This conclusion corroborates a recent taxonomic work that grouped S. globula, S. itapevi, and other four Scytodes species in the ‘globula group’.     

扇脉杓兰和无距虾脊兰的核型分析

为了解扇脉杓兰(Cypripedium japonicum Thunb.)和无距虾脊兰(Calanthe tsoongiana T. Tang et F. T. Wang)的核型,采用根尖压片法对扇脉杓兰和无距虾脊兰的染色体数目和核型进行了研究。结果表明,扇脉杓兰体细胞的染色体数为22,核型公式为2n=2x=22=16m+2sm+2st+2t,染色体相对长度组成为2n=22=2L+6M2+12M1+2S,核不对称系数为60.01%,核型分类为2B型;而无距虾脊兰体细胞的染色体数为40,核型公式为2n=2x=40=28m+10sm+2st,染色体相对长度组成为2n=40=8L+10M2+16M1+6S,核不对称系数为59.84%,核型分类为2B型;两者核型都较为对称。其中,无距虾脊兰的核型为首次报道。这为扇脉杓兰和无距虾脊兰的进化地位和种质保护提供了细胞学证据。     

Karyology of theScorzonera (Compositae) species from the Iberian Peninsula

A karyological study of 15 taxa ofScorzonera L. from the Iberian Peninsula has been made. The chromosome numbers found inS. hispanica var.pinnatifida, S. baetica, S. reverchonii, S. angustifolia, S. laciniata var.calcitrapifolia and var.subulata (2n = 14) are new. Diploid cytotypes with 2n = 14 and 2n = 12 prevail, andS. hispanica var.crispatula is the only taxon which exhibits autopolyploidy (2n = 14, 28). x = 7 is considered to be the base chromosome number within the genus, with x = 6 being derived from it by translocation. This and detailed karyotype analyses allow to group the Iberian Peninsula species ofScorzonera into three groups.     

Karyomorphology of Turkish species in Centaurea sections Centaurea and Phalolepis (Asteraceae) and implications for taxonomy

In this paper, 31 mostly endemic and locally distributed Turkish Centaurea taxa belonging to Centaurea and Phalolepis sections were examined in terms of their karyomorphology. The basic chromosome number for all of the studied species was concurringly determined as 9(x = 9) for both sections, excluding C. hierapolitana. We also determined tetraploid and hexaploid species in spite of many species having diploid chromosome numbers. Twelve chromosome counts are reported for the first time and most of the karyotyping analyses are described for the first time via the KAMERAM program. The karyotypes had a predominance of metacentric (m) chromosomes. However, in the karyotyping of six taxa, submetacentric (sm) chromosomes were dominant. Five quantitative asymmetric indices were used to evaluate karyological features of the species. A meaningful dendrogram was carried out to assess the karyotype-symmetry conditions and describe the karyotyping relationships between different taxa.     

Karyology of Aconitum subgenus Lycoctonum (Ranunculaceae) from China,with a report of the new base chromosome number x = 6 in the genus Aconitum

In order to gain better knowledge of the number and morphology of chromosomes in Aconitum subgen. Lycoctonum in China, 60 populations belonging to 20 species were cytologically studied. Chromosome numbers of six species (A. apetalum, A. finetianum, A. fletcheranum, A. longecassidatum, A. umbrosum and A. wangyedianense) are here reported for the first time. One species, A. fletcheranum, has 2n = 12, and thus is a diploid based on x = 6, a new base chromosome number for the genus Aconitum. Most of the remaining taxa are diploid (2n = 16) based on x = 8, but five taxa (A. angustius, A. brevicalcaratum var. brevicalcaratum, A. brevicalcaratum var. parviflorum, A.chrysotrichum and A. crassiflorum) are tetraploid with 2n = 32, and one species (A. apetalum) is hexaploid with 2n = 48, the highest ploidy level currently known in the subgenus. Disregarding differences in the presence or absence and number of satellites, the karyotypes of all the 2n = 16 species are quite uniform (2n = 2m + 6sm + 8st), but A. novoluridum, the only species of A. section Alatospermum, has an intrachromosomally less asymmetric karyotype (2n = 2m + 14sm), which lends further support for the primitive condition of its section as inferred from gross‐morphology. Chromosomal variation in the subgenus and the relationships of some of the species are discussed.     

Crossing relationships and chromosome numbers of Solanum section Solanum in Uganda

The ability of taxa to cross/hybridize is useful information for plant systematists and breeders. Crossability reflects reproductive isolation and the biological species concept stresses the need for reproductive isolation between species to maintain morphological distincness. For plant breeders knowledge on crossing ability facilitate selection of taxa for character improvement breeding. In this study, the crossing relationships and chromosome numbers within and among Ugandan species of Solanum sect. Solanum is studied by making 800 crosses involving 246 combinations. Less than half of these combinations were successful, producing F1 offspring. All studied accessions are self‐compatible and most accessions crossed readily with accessions of their own species. Interspecific crossings failed either to yield seeds, yielded F1 seeds that did not germinate, or resulted in F1s that did not have stainable pollen – implying a crossing barrier; or stainable pollen, but with chromosome numbers that indicated reproduction by apomixis. The results support the taxonomic treatment of Solanum based on classical, numerical and partly molecular evidences. The material studied represents eight Ugandan taxa: S. americanum, a diploid (2n = 2x = 24); five tetraploids (2n = 4x = 48) S. florulentum, S. memphiticum, S. tarderemotum, S. villosum ssp. villosum and S. villosum ssp. miniatum; and two hexaploids (2n = 6x = 72) S. scabrum subsp. scabrum and S. scabrum subsp. laevis. In addition to confirming the ploidy levels of the Ugandan accessions, the ploidy levels of S. florulentum, S. memphiticum and S. tarderemotum are reported for the first time. Non‐Ugandan material of Solanum sarrachoides was found to be diploid. Knowledge of the crossing behaviour and ploidy levels in Solanum will facilitate breeding for character improvement in these important species that are used commonly as food and/or medicine in eastern Africa.     

A sex-chromosome mutation in Silene latifolia

Silene latifolia is dioecious, yet rare hermaphrodites have been found, and such natural mutants can provide valuable insight into genetic mechanisms. Here, we describe a hermaphrodite-inducing mutation that is almost certainly localized to the gynoecium-suppression region of the Y chromosome in S. latifolia. The mutant Y chromosome was passed through the megaspore, and the presence of two X chromosomes was not necessary for seed development in the parent. This result supports a lack of degeneration of the Y chromosome in S. latifolia, consistent with the relatively recent formation of the sex chromosomes in this species. When crossed to wild-type plants, hermaphrodites performed poorly as females, producing low seed numbers. When hermaphrodites were pollen donors, the sex ratio of offspring they produced through crosses was biased towards females. This suggests that hermaphroditic S. latifolia would fail to thrive and potentially explains the rarity of hermaphrodites in natural populations of S. latifolia. These results indicate that the Y chromosome in Silene latifolia remains very similar to the X, perhaps mostly differing in the primary sex determination regions.     

Karyotype analysis in some species of Consolida (Ranunculaceae) from Iran

Consolida (dc .) S. F. Gray belongs to Ranunculaceae. The genus includes about 52 species worldwide. Here we report the diploid chromosome number and chromosome size and morphology for six Consolida species. For C. anthoroidea, C. leptocarpa, C. paradoxa and C. rugulosa the diploid chromosome number is reported for the first time. All investigated species have a diploid chromosome number of 2n = 2x = 16, except for C. persica having 2n = 2x = 14. The karyotypes of all six taxa are asymmetric, consisting of all four major chromosome types: metacentric, submetacentric, subtelocentric and telocentric chromosome type. However, considering the karyotype formula, all six species could be distinguished. In all taxa, metacentric chromosome pair 1 possesses a satellite. The only exception is C. rugulosa having an additional satellite positioned on metacentric chromosome pair 2. Karyotype data allow the separation of Aconitella from Consolida. Karyotype data plus morphological evidence support the reduction of C. paradoxa to formae level of C. rugulosa. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

FISH-mapping of 18S ribosomal RNA genes and telomeric sequences in the Japanese bitterlings Rhodeus ocellatus kurumeus and Tanakia limbata (Pisces,Cyprinidae) reveals significant cytogenetic differences in morphologically similar karyotypes

The Japanese rose bitterling, Rhodeus ocellatus kurumeus, and the oily bitterling, Tanakia limbata, were cytogenetically studied by silver (Ag)- and chromomycin A₃ (CMA₃)-staining, by C-banding and by mapping of the 18S ribosomal genes and of the (TTAGGG) _n telomeric sequence. These two representative species of related genera of the subfamily Acheilognathinae show very similar chromosome complements. Nevertheless, significant differences in the chromosomal distribution of nucleolus organizer regions (NORs) and interstitial telomeric sequences were observed. Whereas R. ocellatus kurumeus shows a single NOR-bearing chromosome pair, T. limbata is characterized by a higher number of variable NORs. Multiple telomeric sequence sites were found at the pericentromeric regions of several chromosomes in the rose bitterling. No telomeric sequence sites were detected near centromeres, but they were found to be scattered along the NORs in the oily bitterling. Two karyoevolutive trends might have been identified in the subfamily.     

CYTOTAXONOMY OF CESPITOSE ZINNIAS

Torres , Andrew M. (U. Wisconsin, Milwaukee.) Cytotaxonomy of cespitose zinnias. Amer. Jour. Bot. 49(10): 1033–1037. Illus. 1962.—The results of hybridization studies among 5 of the 6 cespitose species of Zinnia are reported. Analyses of meiosis in the F₁ hybrids suggest there are 2 genomes, A and B, in the polyploid taxa. The A genome apparently exists in the diploid state in 2 species, but the B genome is known only from polyploid taxa. The chromosome number of Z. oligantha (2n = 20) is reported for the first time.     

Cytogenetic studies in the genus Zea

Summary New cytological evidence supporting x = 5 as the basic chromosome number of the genus Zea has been obtained as a consequence of our analysis of the meiotic configurations of Zea mays ssp. mays, Z. diploperennis, Z. perennis and of four F₁ artificial interspecific hybrids. Z. mays ssp. mays (2n = 20) presents regular meiosis with 10 bivalents (II) and is considered here as a typical allotetraploid (A₂A₂B₂B₂). In Z. diploperennis (2n = 20) 10II are formed in the majority of the cells, but the formation of 1III + 8II + 1I or 1III + 711 + 3I in 4% of the cells would indicate its segmental allotetraploid nature (A₁A₁B₁B₁). Z. perennis (2n = 40) had 5IV + 10II in 55% of the cells and would be considered as an auto-allooctoploid (A₁A₁A'₁A'₁C₁C₁C₂C₂). Z. diploperennis x Z. mays ssp. mays (2n = 20) presents 10II in ca. 70% of the cells and no multivalents are formed. In the two 2n = 30 hybrids (Z. mays ssp. mays x Z. perennis and Z. diploperennis x Z. perennis) the most frequent meiotic configuration was 5III + 5II + 5I and in 2n = 40 hybrid (Z. diploperennis x Z. perennis) was 5IV + 10II. Moreover, secondary association was observed in the three abovementioned tetraploid taxa (2n = 20) where one to five groups of two bivalents each at diakinesis-metaphase I was formed showing the affinities between homoeologous genomes. The results, as a whole, can be interpreed by assuming a basic x = 5 in this polyploid complex. The main previous contributions that support this working hypothesis are reviewed and its phylogenetic implications studied are discussed.     

Étude cytotaxinomique de quelquesDipsacaceae d'Iran

Chromosome numbers for 28 Iranian populations ofDipsacaceae, corresponding to 14 taxa, are presented. New are those forScabiosa aff.olivieri var.pinnatisecta, S. persica, Pterocephalus canus, P. kurdicus, Dipsacus strigosus, Cephalaria dichaetophora, C. hirsuta, C. microcephala, C. subindivisa andC. aff.sublanata. Except forC. syriaca (x = 5) andC. dichaetophora (x = 7 : new basic chromosome number forCephalaria), all species examined are characterized by the basic chromosome number (x = 9). Instances of aneusomaty, B-chromosomes, aneuploidy, dysploidy, and polyploidy have also been found.

     

On the taxonomic position ofSilene thebana (Caryophyllaceae)

Silene thebana Orph. exBoiss. is transferred as a subspecies toS. fabaria (L.)Sm., resulting in the new combinationS. fabaria (L.)Sm. subsp.thebana (Orph. exBoiss.)Melzh. The chromosome count of 2n = 24 is recorded for the first time for this taxon.Dedicated to Prof. DrK. H. Rechinger on the occasion of his 80th birthday, 16th October 1986.     

CYTOGEOGRAPHICAL STUDIES IN THE GENUS ARNICA (COMPOSITAE: SENECIONEAE). I

A total of 134 chromosome counts representing 21 taxa of the genus Arnica are presented. Counts are published here for the first time for A. lonchophylla (n = 38) and A. nevadensis (n = 38). Ten previously unreported counts representing 9 taxa are also presented. The basic chromosome number of the genus is x = 19. With respect to chromosome number, the genus exhibits maximum diversity in the Rocky Mountains of Colorado and Wyoming. Arnica angustifolia, A. cordifolia and A. mollis are recognized as mature polyploid complexes, containing several wide ranging polyploid races and only a few highly restricted or scattered diploid races. Within the genus in general, diploids tend to be restricted to unglaciated areas while polyploids are much wider ranging, particularly in unglaciated areas.