Karyotype analysis of some Minuartia L. (Caryophyllaceae) taxa

Karyotypic characters, mitotic metaphase chromosomes, monoploid idiograms and karyograms of Minuartia anatolica (Boiss.) Woronow var. phrygia (Bornm.) McNeill, Minuartia anatolica (Boiss.) Woronow var. scleranthoides (Boiss. & Noe) McNeill, Minuartia corymbulosa (Boiss. & Balansa) McNeill var. gypsophilloides McNeill and Minuartia aksoyi M.Koç & Hamzao?lu were investigated for the first time. Analysis of somatic metaphases showed that the chromosome numbers and the formulas of these taxa were 2n = 24 = 14m + 6sm + 4st for Minuartia anatolica var. phrygia, 2n = 14 = 6m + 8sm for Minuartia anatolica var. scleranthoides, 2n = 14 = 6m + 4sm + 4st for Minuartia corymbulosa var. gypsophilloides and 2n = 30 = 14m + 10sm + 6st for Minuartia aksoyi. No satellites were observed in the karyotypes of these taxa. Karyotype asymmetry was estimated by many different methods, namely the Stebbins classification, the karyotype asymmetry index (As K %), the total form percent (TF %), the Rec and Syi indices, the intrachromosomal asymmetry index (A1) and interchromosomal asymmetry index (A2), the dispersion index (DI), the degree of asymmetry of karyotype (A index) and the asymmetry index (AI).     

Cytogenetics, geographical distribution, pollen stainability and fecundity of five diploid taxa of Santolina rosmarinifolia L. aggregate (Asteraceae: Anthemideae)

The chromosome analysis of Santolina rosmarinifolia subsp. rosmarinifolia, S. oblongifolia, S. semidentata subsp. semidentata, S. semidentata subsp. melidensis, S. canescens and the hybrid complex (S. rosmarinifolia subsp. rosmarinifolia, S. oblongifolia and their putative hybrids) shows that all the taxa are diploids (2n = 2x = 18; 18 + 1 or more B chromosomes, with 2n = 19, 20 only in the hybrid complex). The results show a conserved general structure of the karyotype (14m + 2sm + 2st), but in S. semidentata subsp. melidensis it is variable, with 14m + 2sm + 2st in ten individuals, 14m + (1m ? 1sm) + (1 m ? 1st) in nine individuals and 12m + (1m ? 1sm) + (1m ? 1st) + 2st + 1B in five individuals. Tetraploid individuals occurred in the diploid populations of S. rosmarinifolia subsp. rosmarinifolia and S. canescens, and their autopolyploid origin is discussed. Multivalent configurations at diakinesis, simple and double chromosome bridges and delayed disjunction of homologous and non-homologous chromosomes at anaphase I have negative effects on pollen stainability. The mean fructification percentage is moderate. The results suggest that the complex is a mosaic of introgressive hybrids.     

A new species of Lysimachia (Myrsinaceae) from Dabieshan Mountain,China

A new species of Myrsinaceae, Lysimachia jinzhaiensis S.B. Zhou & K. Liu, is described and illustrated from Dabieshan mountain, Anhui, China. It is similar to L. christiniae in the prostrate stem, opposite leaves, yellow flowers born singly in leaf axils, but differs by being glabrous throughout or glandular on young parts, and having quadrangular stem, corolla with densely transparent glandular, orange-red corolla base with lobes being significantly overlapping and contorting to left in bud. Moreover, L. jinzhaiensis have a different karyotype, formulated as 2n = 2m + 2sm + 10st (2SAT) + 10t.     

Cytogenetics, Geographical Distribution, Pollen Stainability and Fecundity of Santolina impressa (Asteraceae: Anthemideae)

Santolina impressa (2n = 2x = 18) is an endemic species of Portugal, with restricted geographical distribution. The present study aimed to explore its chromosomal variation in respect to chromosome morphology, meiotic behaviour, and effects on pollen stainability and fecundity. Its karyotype formula was found to be either 12m + 2m^sat + 2sm^sat + 2st (75% of the individuals) or 12m + 2m^sat + 3sm + 1sm^sat (25% of the individuals). Univalents were observed in 29.21% of the meiocytes. Chromosome fragments due to breakage in the chromosome arm were observed in 10 meiocytes only (11.23% of the meiocytes). Chains and rings of trivalents were observed in 14.60% of the meiocytes (one trivalent per meiocyte was observed). Chains and rings of quadrivalents were observed in 21.34% and 11.23% of the meiocytes, respectively, with a range of 0–1 per cell. Nine plants (40.90% of the total) with 2n = 2x = 18 + 2B showed a quadrivalent configuration in diakinesis. Twenty abnormal anaphases with delayed disjunction of the four non-homologous and the two homologous chromosomes were observed. Simple chromosome bridges without fragments and interchromosomal adhesions were observed in 35.95% of the anaphases analyzed. B chromosomes showed bivalent association in diakinesis and their segregation at anaphase I was normal. Pollen was found to be fertile (mean ± s.d. = 89.57 ± 47.14%); the effect of univalent frequency and frequency of abnormal anaphase I on pollen stainability was strong and statistically significant.     

Considerations on karyotype evolution in the genera Imparfinis Eigenmann and Norris 1900 and Pimelodella Eigenmann and Eigenmann 1888 (Siluriformes: Heptapteridae)

Heptapteridae is one of the fish families of the order Siluriformes with a wide distribution throughout the basins of the Neotropical region. The genera Imparfinis and Pimelodella comprise few species and/or populations with some chromosome information. Specimens of Imparfinis schubarti, Imparfinis mirini, and Pimelodella meeki from different sites located in the Paranapanema River Basin/PR/Brazil were cytogenetically analyzed. The two species of the genus Imparfinis exhibited 2n = 58 and FN = 116: I. schubarti, with a karyotypic formula of 30m + 28sm and I. mirini with a karyotype formula of 36m + 22sm. P. meeki presented a karyotype of 2n = 46 characterized by 26m + 14sm + 6st and FN = 92, confirming a variability in the 2n of the Heptapteridae family. Both Imparfinis species exhibited interstitial NORs in pair 1, coincident with a secondary constriction; P. meeki presented NORs located in the terminal position on the short arm of pair 17. All AgNORs were coincident with 18S rDNA probe and CMA₃ positive. P. meeki showed a small amount of heterochromatin rich in AT and GC bases. The heterochromatin in I. schubarti was CMA₃ positive. In I. mirini the heterochromatin was DAPI-positive. Furthermore, the long arm of one of the chromosomes of pair 19 revealed the presence of heterochromatic heteromorphism only in male individuals. After meiotic analyses, this heteromorphism could be easily identified in the pachytene and metaphase I stages, and was heteropyknotic and DAPI positive. This feature may be an indication of initial differentiation of sex chromosomes in I. mirini, increasing the great karyotypic variability within this family of fish.     

A cyto-evolutional study of Campanumoea Blume (Campanulaceae) and a possible pathway for secondary karyotype formation

Campanumoea is a small genus in the family Campanulaceae, with species divided into sections Campanumoea and Cyclocodon. Sixteen accessions from Campanumoea and related genera native to China were used to study their karyotype. The results showed that chromosome characteristics were different between the two sections. For Campanumoea, the karyotypic formula was 2n = 2X = 2m + 12sm + 2st = 16,3A and for Cyclocodon it was 2n = 2X = 6m + 12sm = 18,3B. These data, combined with chromosomal length characteristics, support the restoration of section Cyclocodon as a genus. However, the incorporation of section Campanumoea into Codonopsis requires more evidence. Comparison of chromosomal length and haploid set length revealed that chromosomal segment rearrangements occurred within sections of Campanumoea and between genera, with the difference within sections being greater than that between genera. Therefore, chromosomal segment rearrangements are present in Campanulaceae, implying that chromosomal segment rearrangement plays an important role in the evolution of diversity in Campanulaceae. By comparing the chromosomal characteristic in section Campanumoea and the genus Adenophora, we concluded that the secondary chromosome type such as n = 17, 18 would be derived by autopolyploidization of n = 9, and by chromosome fusion.     

7种绢蒿属植物染色体数目和核型研究

首次报道了中国绢蒿属[Seriphidium (Bess.) Poljak.]7种植物的染色体数目和核型,其核型公式分别为:西北绢蒿[S.nitrosum (Web.ex Stechm.) Poljak.]2n=2x=18=6m(2SAT)+8sm +2st+2T;沙漠绢蒿[S.santolinum (Schrenk) Poljak.]2n=2x=18=14m+4sm;博洛塔绢蒿[S.borotalense (Poljak.) Ling et Y.R.Ling]2n=2x=18=2M+14m+2sm;新疆绢蒿[S.kaschgaricum (Krasch.) Poljak.]2n=2x=18=8m(2SAT)+10sm(2SAT);纤细绢蒿[S.gracilescens (Krasch.et Iljin) Poljak.]2n=2x=18=4m+14sm(2SAT);三裂叶绢蒿[S.junceum (Kar.et Kir.) Poljak.]2n=2x=18=10m+4sm+4st;民勤绢蒿[S.minchünensa Y.R.Ling]2n=2x=18=12m+6sm.结果表明,7种绢蒿植物中,博洛塔绢蒿最原始,西北绢蒿最进化.     

Cytogenetics of Alismatales s.s.: chromosomal evolution and C-banding

Ten species of Alismatales, five of Alismataceae, four of Limnocharitaceae and one of Hydrocharitaceae were studied with regard to chromosome number, chromosome morphology, and pattern of Giemsa C-bands. The genus Echinodorus had a diploid chromosome number of 22 for all species that were analyzed and a karyotypic formula of 2m + 20a. For the family Limnocharitaceae, Hydrocleys nymphoides had a diploid chromosome number of 16, Hydrocleys martii (4m + 2sm + 10a) had a diploid chromosome number of 16, Limnocharis flava had a diploid chromosome number of 20 and L. laforestii (4m + 16a) had a diploid chromosome number of 20. The only species of Hydrocharitaceae that was studied exhibited a karyotype that consisted of a diploid chromosome number of 28 and a karyotypic formula of 4m + 6sm + 4a. The distribution pattern of the C-banded karyotype in Echinodorus showed four blocks of constitutive heterochromatin in two smaller acrocentric pairs that corresponded to the heterochromatic NORs. In E. lanceolatus, 14 bands in the termini of the arms beyond the heterochromatic NORs of seven acrocentric pairs were also observed. Idiograms are presented and the karyotypic evolution patterns for the studied groups are discussed.     

XX/XO, a rare sex chromosome system in Potamotrygon freshwater stingray from the Amazon Basin, Brazil

Potamotrygonidae is a representative family of South American freshwater elasmobranchs. Cytogenetic studies were performed in a Potamotrygon species from the middle Negro River, Amazonas, Brazil, here named as Potamotrygon sp. C. Mitotic and meiotic chromosomes were analyzed using conventional staining techniques, C-banding, and detection of the nucleolus organizing regions (NOR) with Silver nitrate (Ag-NOR). The diploid number was distinct between sexes, with males having 2n = 67 chromosomes, karyotype formula 19m + 8sm + 10st + 30a, and fundamental number (FN) = 104, and females having 2n = 68 chromosomes, karyotype formula 20m + 8sm + 10st + 30a, and FN = 106. A large chromosome, corresponding to pair number two in the female karyotype, was missing in the male complement. Male meiotic cells had 33 bivalents plus a large univalent chromosome in metaphase I, and n = 33 and n = 34 chromosomes in metaphase II. These characteristics are consistent with a sex chromosome system of the XX/XO type. Several Ag-NOR sites were identified in both male and female karyotypes. Positive C-banding was located only in the centromeric regions of the chromosomes. This sex chromosome system, which rarely occurs in fish, is now being described for the first time among the freshwater rays of the Amazon basin.     

New cytological data in Ophrys sect. Pseudophrys Godfery and comparative karyomorphological studies in Ophrys L. (Orchidaceae)

Eight species of Ophrys sect. Pseudophrys (Orchidaceae) were cytogenetically studied. The analysed species possess the most symmetrical karyotypes of the genus (M_CA ranged from 10.21 to 15.87 and CV_CL from 19.61 to 23.93) with 2n = 2x = 36, being composed of mainly metacentric chromosomes. The karyotype formulae were: 36m for Ophrys archimedea, 32m + 4sm for O. flammeola, 32m + 4sm for O. funerea, 36m for O. laurensis, 36m for O. lojaconoi, 34m + 2sm for O. lucifera, 34m + 2sm for O. obaesa and 36m for O. pallida. Karyotype morphometric characters were evaluated by calculating M_CA and CV_CL for the assessment of karyotype asymmetry, and CV_CI for the evaluation of heterogeneity in the position of the centromeres. The relationships between species were thus finally elucidated. The species characterised by wide distribution show greater karyomorphological distance than those with restricted distribution. The possible evolutionary role of chromosomal rearrangements as well as gene mutations in the speciation of Ophrys is discussed.     

Ploidy variation in Trigonobalanus verticillata (Fagaceae)

Cytological studies were carried out on two populations of Trigonobalanus verticillata in Yinggeling, Hainan Province, China (YGL), and Fraser’s Hill, Malaysia (FH). In the two 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 2n = 2x = 14 (YGL) and 2n = 6x = 42 (FH), representing diploid and hexaploid respectively. The basic chromosome number of the species was x = 7; this is a unique number in the Fagaceae and in the Fagales as well. The characteristic karyotype of the diploid population in China was 2n = 14 = 8m + 4sm + 2st. Based on the new finding of the chromosome number in this study, we clarify the previous dispute about the basic chromosome number and propose that the two Asian Trigonobalanus species have closer affinity.     

Cytogenetic study on some Fritillaria species of Iran

Five species (14 ecotypes) belonging to three subgenera of ornamental-medicinal Iranian Fritillaria plant were chromosomally and karyotypically assessed, using squash technique and 1 % (w/v) aceto-orcein stain. All species were diploid (2n = 2x = 24) having mean chromosome length of 16.8 μm (14.2–18.6 μm). The satellites varied in number (1–4 pairs) and in size (1.27–3.01 μm): mostly locating on long arms. Four chromosome types (“m”, “sm”, “st”, “T”) formed 11 different karyotypic formulas: the latter is being reported for the first time in some ecotypes in either S1 or S4. Nine chromosomal parameters were calculated. ANOVA verified intra- and inter-specific chromosomal variation in examined Iranian Fritillaria species. Twelve different methods were used to assess the degree of karyotype asymmetry. Among those, one qualitative (Stebbins classification) and seven quantitative (TF %, CV_TL, DI, AsK %, A2, Rec, CG %) parameters verified that S2 and S5 species were recognized as having the most asymmetrical and symmetrical karyotypes, respectively.     

蟛蜞菊属和孪花菊属(菊科-向日葵族)的细胞学研究

研究了菊科向日葵族鳢肠亚族蟛蜞菊属(Sphagneticola O. Hoffm.)和孪花菊属(Wollastonia DC. ex Decne.)各2种植物的染色体数目和染色体形态。蟛蜞菊[S. calendulacea (L.) Pruski]的染色体数目为2n=50, 核型公式为2n=18m+30sm+2st,南美蟛蜞菊[S. trilobata (L.) Pruski]的染色体数目为2n=56, 核型公式为2n=24m+28sm+4st, 孪花菊[W. biflora (L.) DC.]的染色体数目为2n=30,核型公式为2n=24m+4sm+2st,山孪花菊[W. montana (Blume) DC.]的染色体数目为2n=74, 核型公式为2n=37m+31sm+6st。根据上述结果并结合以前的有关资料,推测蟛蜞菊属的染色体基数可能为x=14和x=25,而不应是x=15。该属的3个新世界热带种[S. brachycarpa (Baker) Pruski、S. gracilis (Richard) Pruski和南美蟛蜞菊]可能都基于x=14, 其中S. gracilis为二倍体(2n=2x=28), S. brachycarpa和南美蟛蜞菊为四倍体(2n=4x=56); 唯一的亚洲种(蟛蜞菊)可能是基于x=25的二倍体(2n=2x=50)。染色体资料不支持将山孪花菊(x=37)这一植物置于孪花菊属(x=15)中。     

Karyotype analysis of the southernmost South American species of Stemodia (Scrophulariaceae)

Abstract

The aim of the present study was to examine the somatic chromosomes of seven species of Stemodia (Scrophulariaceae). The karyotypes of Stemodia ericifolia (2n = 22 = 20m + 2 sm), S. hassleriana (2n = 22 = 20m + 2sm), S. hyptoides (2n = 22 = 20m + 2sm), S. hyptoides (2n = 44 = 40m + 4sm), S. lobelioides (2n = 44 = 40m + 4sm) and S. stricta (2n = 22 = 20m + 2sm) were analyzed for the first time. All the species studied showed a predominance of metacentric chromosomes and a lower proportion of submetacentric pairs. The chromosomes in all the species were found to be small with a mean chromosome length of 1.42 μm, varying from 0.77 μm in S. hyptoides (2n = 66) to 2.10 μm in S. lanceolata. The differences in the asymmetry of the karyotypes were small, for which it is possible to assume that the great diversification of the genus has been accompanied by very small changes in the structure of the chromosomes.     

Karyological data of 47 accessions of 28 Artemisia (Asteraceae, Anthemideae) species from Iran, with first new reports for Iranian populations and first absolute counts in three species

Somatic chromosome numbers of 47 accessions representing 28 Artemisia species are provided from Iran. Two basic chromosome numbers, x = 8, 9, each with diploid, tetraploid and hexaploid levels, were found. Different chromosome numbers, 2n = 16, 16 + 1B, 16 + 5B, 32, 48, and 2n = 18, 18 + 1B, 19, 36, 36 + 1B, 36 + 2B, 37, 49 + 2B, 49 + 3B, 51 + 6B, 54, 54 + 1B, 54 + 3B, 54 + 5B, in studied accessions were identified. Chromosome numbers are reported for the first time in three species, counts in four species are new for Iran, and other counts have been thoroughly compared to previous data. Forty percent of the studied accessions are polyploid and B-chromosome(s) are reported in 17 % of accessions. Aneuploidy and aneusomy are other relevant cytological phenomena. Some karyological parameters, total karyotype length, karyotype formula, mean value of centromeric indices, mean arm ratio, A ₁ and A ₂ indices, were estimated to characterize the karyotypes numerically. A ₁ and A ₂ indices showed that karyotypes tend to be asymmetric in polyploid and dysploid taxa. PCA analysis of all karyological parameters has shown some systematic and evolutionary implications. The consideration of all these chromosome numbers and cytogenetic mechanisms has led us to infer the different patterns of chromosomal evolution in the genus.     

Karyological features and banding patterns in Arachis species belonging to the Heteranthae section

The section Heteranthae of Arachis is endemic to Brazil, occurring mainly in the semi-arid northeastern region. The section is considered derived within the genus and includes only annual herbs. Most previous cytological evaluations were restricted to chromosome numbers and morphology. The present approach comprised karyomorphological evaluation in 10 accessions from five species of this section, including standard staining and fluorochrome banding [chromomycin A3 (CMA)/4′,6-diamidino-2-phenylindole (DAPI)]. All accessions presented diploid chromosome numbers (2n = 20) with a prevalence of metacentric to submetacentric chromosome morphology. Arachis dardani, Arachis pusilla, and Arachis interrupta presented karyotypic formula 18m + 4sm and satellite type 2, while Arachis sylvestris and Arachis giacomettii presented 16m + 4sm and satellite type 10. Despite the conserved morphological features, higher diversity was detected in terms of size and number of GC-rich (CMA⁺) heterochromatic blocks among the species; however, all of them were located in the pericentromeric regions. The species A. pusilla presented the highest number of GC-rich blocks, present in all chromosomes of the complement. Based on the data obtained and considering literature data, we suggest that A. dardani and A. interrupta occupy a basal position in the group due to their moderate asymmetry and satellite type. At least in A. pusilla, the constitutive heterochromatin seems to have suffered recent modifications of its constitution, in contrast to other species that present pericentromeric CMA⁺ blocks in all chromosomes. A. giacomettii and A. sylvestris are closely related to each other and also similar to the previously studied Arachis seridoensis, revealing two clear-cut subgroups within the section from the karyological point of view.     

华南地区3种兔儿风属植物(菊科-帚菊木族)的细胞学研究

首次报道了华南地区兔儿风属(Ainsliaea DC.)(菊科-帚菊木族Asteraceae-Pertyeae)3种植物共4个居群的染色体数目和核型。其中长穗兔儿风(A.henryi Diels)的染色体数目为2n=24,核型公式为2n=16m+8sm;三脉兔儿风(A.trinervis Y.C.Tseng)的染色体数目为2n=26,核型公式为2n=16m+10sm;莲沱兔儿风(A.ramosa Hemsl.)2个居群的染色体数目均为2n=26,核型公式为2n=26=22m+4sm。所有居群的染色体由大到小逐渐变化,核型没有明显的二型性。这些结果表明兔儿风属植物确有x=12和x=13两个基数,其中x=13可能是该属的原始基数。     

Cytotaxonomy of autumnal flowering species of Hyacinthaceae from Algeria

Cytotaxonomic investigations of the autumn-flowering squills, Prospero autumnale (L.) Speta ≡ Scilla autumnalis L., Prospero obtusifolium (Poir.) Speta ≡ Scilla obtusifolia Poir., Barnardia numidica (Poir.) Speta ≡ Scilla numidica Poir., and Hyacinthoides lingulata (Poir.) Rothm. ≡ Scilla lingulata Poir. were performed in 20 populations from northern Algeria located between Tipasa and La Vieille Calle. Various chromosome numbers were found, including a new cytotype, 2n = 8, for the flora of Algeria, concerning plants identified as Prospero obtusifolium (Poir.) Speta [including P. fallax (Steinh.) Speta = S. autumnalis L. ssp. fallax (Steinh.) Batt.]. The numbers 2n = 14, 28, and 42 correspond, respectively, to diploid, tetraploid, and hexaploid levels of P. autumnale s.l. [including P. pulchellum (Munby) Speta ≡ Scilla pulchella Munby = S. autumnalis var. pulchella (Munby) Batt.], with x = 7. The cytotypes of Barnardia numidica (Poir.) Speta with 2n = 18 and Hyacinthoides lingulata (Poir.) Rothm. with 2n = 16 chromosomes were confirmed.     

仙茅属三个国产种的核型研究

本文报道了中国产三种仙茅植物的核型。1.绒叶仙茅Curculigo crassifolia (Baker) Hook. f., 2n=2x=18=10m(4SAT) 8 sm;2.大叶仙茅C.capitulata(Lour.)O. Kuntze,2n=2x=18=10(2SAT) 8sm;3.中华仙茅C.sinensis S.C.Chen,2n=2x=18=8m(3SAT) 10sm(2SAT)。其中中华仙茅的核型为首次报道。虽然三种仙茅的核型都是“2B”型,但中华仙茅的核型不对称性比绒叶仙茅和大叶仙茅强。     

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.