Total Haploid Chromosome Length Research Articles

Karyotype, Male Meiosis, and Pollen Features of Barleria (Acanthaceae): A Wild Ornamental From India.

Barleria is a palaeotropical genus of herbs, shrubs, and rarely climbers or trees. We investigated the karyotypes and male meiosis of 12 and 13 species, respectively, for the first time. Mitotic metaphases revealed two chromosome counts, 2n = 40 and 2n = 44. Chromosomes had median (m), submedian (sm), and subterminal (st) region centromeres. The total haploid chromosome length (TCL) ranged from 78.95 µm (Barleria sahyadrica) to 37.80 µm (B. nitida). Dispersion index differentiated the species into two groups, one with lower (3.40-4.79) and the other with higher (6.63-12.87) values. Principal component analysis based on six karyological parameters, namely base number (x), 2n, TCL, coefficient of variation of chromosome length, coefficient of variation of centromeric index, and mean centromeric asymmetry, exhibited three clusters. Cluster I included species of the subgenus Barleria. Cluster III had species of the subgenus Prionitis section Somalia. Cluster II comprised species of the subgenus Barleria and the subgenus Prionitis section Prionitis (B. sahyadrica). Pollen grains were oblate spheroidal or distinctly three-lobed, tri-brevicolporate with honey-combed tectum. Our analyses revealed karyological relationships among the investigated species and also provide raw data to breeders interested in horticultural applications of Barleria for accomplishing interspecific hybridization.

The Detailed Karyotype Analysis, Karyotype Asymmetry and Polyploidy in Hemp (Cannabis sativa L.)

Hemp (Cannabis sativa L.) is an economical plant with a diploid chromosome number of 2n = 20 and used in many areas, especially in industry. The aim of this study is to perform detailed karyotype analysis and detailed chromosomal measurements using five different genotypes of the plant known as diploid chromosome number 2n = 20, to determine the karyotype asymmetry for the first time, and to investigate the polyploidy variations. The diploid chromosome number and karyotype formula were 2n = 2x = 20 = 18m + 2sm. The karyotype had small metacentric and submetacentric chromosomes. The smallest chromosome length, largest chromosome length, total haploid chromosome length, and average haploid chromosome length were 2.41, 3.55, 29.87, and 2.99 μm, respectively. Intrachromosomal and interchromosomal karyotype asymmetries were calculated using many different parameters, mainly MCA (mean centromeric asymmetry) and CVCL (variation coefficient of chromosome length). According to the asymmetry values, the species had quite symmetrical karyotype. Although the diploid chromosome number was known as 2n = 20, detailed karyotype analysis and karyotype asymmetry data were presented for the first time by this study. In addition, in the study carried out on five different genotypes, polyploidy variation was detected in one genotype.

Cytogenetics of Four Common Shrub Species of the Mexican Xerophile Scrub in the Mezquital Valley, Hidalgo, Mexico

Chromosomal characteristics of Dasylirion acrotrichum (Asparagaceae), Flourensia resinosa, (Asteraceae), Tecoma stans (Bignoniaceae), and Citharexylum brachyanthum (Verbenaceae), common elements of the Mexican xerophile scrub are recorded for the first time. The spreading and air-drying technique in root meristems allowed for obtaining chromosome preparations. Chromosomal parameters such as the diploid number (2n), karyotype formula (KF), total haploid chromosome length (THL), average chromosome size (AC), and asymmetry index (TF%) of the analyzed species were obtained, except in C. brachyanthum where neither KF nor TF%. The karyotype formulae of D. acrotrichum (13m+6sm), F. resinosa (11m+7sm), and T. stans (14m+3m+1stsat) represent the first cytogenetic records in Mexican populations. Differences in KF, AC, and position of the satellites concerning other previously analyzed cogenerics show that speciation involves changes in the size and shape of the chromosomes. The diploid numbers confirm basic numbers (x) already recorded, but a 2n=104 observed in C. brachyanthum and the same number in C. myrianthum from Brazil could modify x=9 in favor of x=13, consistent with karyological variation in Verbenaceae where hybridization and polyploidy, among other numerical variation mechanisms, play an important role in chromosomal differentiation. The taxa studied showed satellites in the short arms of chromosomes with displaced centromere. These data are taxonomically useful and could be associated in part with the geographic distribution of the species.

Curculigo konkanensis (Hypoxidaceae), a new species from the lateritic plateaus of Konkan region of Western Ghats based on morphological and molecular evidence

A new species Curculigo konkanensis, is described from the lateritic plateaus of the Konkan region of Maharashtra, India. The new species is allied with C. brevifolia and C. orchioides but differs in the characters of rootstock, height of plant, leaves, bracts, capsules and seeds. Cytological parameters, Karyotype formula, total haploid chromosome length (THCL), Value of CVCL and MCA also supported the distinctness of C. konkanensis, C. brevifolia and C. orchioides. Based on plastid DNA data, the new species is placed in Curculigo orchoides subclade and shows phylogenetic affinity with Curculigo brevifolia.

Chromosome counts and karyotype analysis of nine taxa in Sorbus subgenera Aria and Micromeles (Rosaceae) from China

Chromosome numbers of nine taxa in Sorbus subgenera Aria (Pers.) Host and Micromeles Decne. were determined. All are diploid with 2n = 2x = 34. Eight out of them: S. alnifolia (Siebold and Zucc.) K. Koch var. angulata S.B. Liang Rehd., S. alnifolia (Siebold and Zucc.) K. Koch var. lobulata (C.K. Schneid.) Rehd., S. dunnii Rehd., S. folgneri (C.K. Schneid.) Rehd., S. hemsleyi (C.K. Schneid.) Rehd., S. lushanensis X. Chen & J. Qiu, S. ochracea (Hand.-Mazz.) J.E. Vidal and S. yuana Spongberg, which are endemic to China, were reported for the first time. One remaining Asian native S. alnifolia var. alnifolia (Siebold and Zucc.) K. Koch, 2n = 34 was confirmed here. The chromosomes size and the total haploid chromosome length varied from 0.91 µm to 3.51 µm and 23.43 μm to 50.04 μm respectively. A predominance of metacentric chromosomes were perceived. Satellites were observed only in taxa of subgenera Micromeles. Nine taxa were classified as 1A, 2A and 2B according to the Stebbins classification. S. yuana in subgenus Aria presents the most symmetrical karyotype according to all the 11 quantitative indices analyzed, while S. dunnii and S. ochracea in Micromeles present the most asymmetrical karyotypes according to different indices.

Astragalus stenosemioides (Fabaceae)’in karyotip analizi

In this research the metaphase chromosome number and karyotype of Astragalus stenosemioides species growing naturally in Turkey are studied. The study revealed that the chromosome number of A. stenosemioides is 2n = 16. The basic chromosome number of species is determined as x = 8. The karyotype formula of A. stenosemioides is 8m. The total length of the somatic chromosomes of A. stenosemioides ranges between 1.96 - 3.38 μm. The total haploid chromosome length of A. stenosemioides is determined as 21.36 μm. In addition, the karyotype asymmetry of the species was evaluated by different methods; Stebbins classification, TF%, AsK%, Syi and Rec, A1, A2, DI, A, and AI.

Assessing karyotype diversity in the genus Lathyrus L. (Fabaceae)

AbstractAlthough substantial information on the karyological measures of Lathyrus is available, no study has collected and analysed such data to assess the relationship among its taxa. Hence, the present study examined the degree and trends of chromosome diversity in this genus in congruence with Kupicha's sectional classification. Karyo‐morphological data for 74 species representing 11 sections of Lathyrus were collected through the literature survey. The karyological measures included were the total haploid chromosome length (THL), somatic chromosome number (2n), basic chromosome number (x), and five other parameters of karyotype asymmetry (CVCL, CVCI, MCA, A1, and A2). Basic chromosome number (x = 7) and somatic chromosome number (2n = 14) remained stable throughout the genus. Mean karyotypes revealed marked variations in karyotype structure among the 11 sections of Lathyrus. Further, key differences were identified during comparisons of various measures of karyotype asymmetry. Phylogenetic and principal coordinate analyses exhibited substantial variation among different sections of Lathyrus and out‐group genera. Overall, current findings indicated that the karyotype asymmetry measures can serve as an efficient tool to assess the relationship among different sections of Lathyrus.

Karyotype analysis of two oribatid mite species (Acari: Oribatida)

The chromosomal parameters and karyotypic relationships may provide very valuable information about speciation and karyotype evolution. In the order Oribatida, the chromosomal data are limited to a few reports. In the present study, the chromosomal data of two species are provided for the first time. The diploid chromosome numbers are 2n = 14 in Oribotritia hermanni Grandjean, 1967 (Oribatida: Oribotritiidae) and 2n = 22 in Hermanniella gibber Kulijev, 1979 (Oribatida: Hermanniellidae) and chromosomes are small holocentric chromosomes. The smallest and largest chromosome sizes are 0.38 μm and 1.08 μm in O. hermanni, respectively. The total haploid chromosome length is 4.88 μm, in O. hermanni, and a higher value of 6.98 μm is recorded in H. gibber. The sex chromosomes could not be identified, because the oribatid mites show weak sexual dimorphism. In this respect, the results of the study provide important contributions to the cytotaxonomy of oribatid mites.

Karyotype analysis and chromosome number for two Cirsium taxa (Asteraceae) in Iran

Cirsium Mill. contains more than 250 species in the world mainly distributed in the Northern hemisphere. Different chromosome numbers with different ploidy levels were reported in this genus. In this study, karyotype details and chromosome numbers were established for two Cirsium taxa in Iran. C. ciliatum subsp. szovitsii and C. echinus had the mitotic chromosome numbers of 2n = 2x = 34. Karyotype analyses showed that chromosomes were generally metacentric and sub-metacentric. In C. echinus, Lowshan population had the longest chromosome (19.10 µm) and Heyran Canyon population (4.73 µm) the shortest one while in C. ciliatum, the longest chromosome was observed in Urmia to Salmas population (14.67 µm) and the shortest one (4.71 µm) in Doshanlu population. Total haploid chromosome length ranged from 275.29 to 376.42 µm in populations studied. Both taxa were grouped in 2B class. B-chromosomes were recorded for two taxa studied too. Chromosome type, mitotic chromosome numbers and occurrence of B-chromosomes were in agreement with previous results (Albers, Pröbsting, 1998; Lövkvist, Hultgård, 1999; Yüksel et al., 2013; Yildiz et al., 2016).

Chromosome evolution in the cosmopolitan genus Lycium (Solanaceae)

AbstractLycium is the only member of tribe Lycieae (Solanoideae, Solanaceae), and it has a cosmopolitan distribution with its greatest diversity in southern South America, southern Africa, and southwestern North America. To date, there has been no attempt to synthesize and evaluate the significance of the available cytogenetical data from a phylogenetic perspective, which is the objective of this study. Firstly, new data on 27 taxa from all its range of distribution (FISH in all of them, banding in 23, Feulgen technique in 14) were provided to fill gaps in the information. The chromosome numbers of L. australe, L. humile, and L. repens were recorded for the first time. Species showed x = 12 with different ploidy levels (mostly diploid or tetraploid), small chromosomes, and symmetrical karyotypes. Lycium fremontii and L. repens were outstanding for having the highest numbers reported for the genus: 10x and 11x, respectively. North American species showed comparatively longer chromosomes. Secondly, cytogenetical traits were mapped on a phylogenetic tree, using character mapping and ancestral states reconstruction, to understand the dynamics of the evolutionary changes. The main cytotaxonomical features were included: chromosome number, presence of polyploidy, total length of the haploid chromosome set, mean chromosome length, karyotype formula, A1 and A2 asymmetry indices, percentage of heterochromatin, number of CMA+/DAPI− NORs bands, and number and position of 5S and 18S‐5.8S‐26S sites. The mean chromosome length, total haploid chromosome length, number of 18S‐5.8S‐26S loci, number of CMA+/DAPI− NORs bands underwent comparatively few transitions compared with the ploidy level and number of 5S loci. The mapping of the characters on the phylogenetic tree showed that the most probable ancestral chromosome number was 2n = 24 with several independent polyploidization events and one pair of each rDNA locus. The most likely ancestral condition for the genus would be: diploid, with small chromosomes, scarce heterochromatin, asynteny of rDNA loci, and one pair of both 18S‐5.8S‐26S and 5S loci.

A NEW SPECIES OF CENTAUREA (ASTERACEAE) FROM TURKEY<br />

A new species of Centaurea (Asteraceae) from Turkey is described and illustrated. Centaurea nallihanense Uysal & Hamzaoğlu occurs on stony slopes of corrupted oak openings in the Province of Ankara in Central Anatolia. It seems to be similar to C. sect. Ptosimopappus but related to the Cheirolepis-Pseudoseridia complex. Diagnostic characters of similar taxa are provided and a comprehensive discussion is held on the basis of molecular and karyological data. The geographical distribution of the new species is mapped. The chromosome number of C. nallihanense, 2n = 2x = 18, counted in root tips, is also reported and illustrated. Its karyotype formula is 6m+3sm. The karyotype of C. nallihanense consists of mainly metacentric chromosomes with the length ranging from 1.113 to 1.771 µm, and the total haploid chromosome length of 12.909 µm. Also, the ITS gene region of the new species is amplified and sequenced to compare with the relatives and to identify the taxonomical position of the new species within Centaurea.

A proposal for a multivariate quantitative approach to infer karyological relationships among taxa

Until now, basic karyological parameters have been used in different ways by researchers to infer karyological relationships among organisms. In the present study, we propose a standardized approach to this aim, integrating six different, not redundant, parameters in a multivariate PCoA analysis. These parameters are chromosome number, basic chromosome number, total haploid chromosome length, MCA (Mean Centromeric Asymmetry), CVCL (Coefficient of Variation of Chromosome Length) and CVCI (Coefficient of Variation of Centromeric Index). The method is exemplified with the application to several plant taxa, and its significance and limits are discussed in the light of current phylogenetic knowledge of these groups.

Morphological, karyological and palynological investigation of endemic Centaurea kurdica Reichardt from Turkey

The purpose of this study was to determine the morphological, morphometrical, karyological and palynological features of the endemic Centaurea kurdica Reichardt species from East Anatolian region. Some morphological features of the species like morphology of capitula, involucra, involucral leaves (phyllaries) and achene have been investigated. The chromosome number of Centaurea kurdica was found as 2n = 18 and haploid karyotype formula 6m+2sm+1M. Metaphase chromosome length ranged from 5.81 to 3.91 μm and the total haploid chromosome length was 41.09 μm. The results of the light microscope investigation of pollen revealed that it is radially symmetrical, isopolar tricolporate and has spheroid-type pollen, and exine ornamentation was also determined as scabrate.

Los rompimientos cromosómicos y translocaciones modelan el cariotipo trimodal de una población hexaploide de Milla biflora (Asparagaceae) de la Reserva Ecológica del Pedregal de San Ángel, Distrito Federal, México

Thirty individuals from one population of Milla biflora from Reserva Ecológica del Pedregal de San Ángel, Distrito Federal, Mexico were sampled to analyze the architecture and behavior of mitotic chromosomes in meristematic root cells. The use of the splash technique allowed the corroboration of the chromosome number 2n=6x=42 (x=7), and to propose the karyotype formula (6m+24sm+12st), to obtain the total haploid chromosome length (106.92μm) mean chromosome size (5.09μm) and chromosomal length range (2.54−9.07μm). The asymmetry index (TF%=32.45) correspond to asymmetric karyotype exhibiting 3 differentiated chromosomal types by their shape and size (trimodal). The NOR regions were associated to st chromosomes bearing a secondary constriction and satellite. Chromosome fragments and heterochromosomes show an active mechanism of chromosomal rearrangements that mold the karyotype of M. biflora and play an important role in the evolution of the species. Its autohexaploide origin is discussed in function of the presence of chromosome subgroups, absence of nucleolar dominance and the role of gene redundancy.

Morphological, karyological features and pollen morphology of endemic Ebenus haussknechtii Bornm. ex Hub.-Mor. from Turkey: A traditional medicinal herb

In this study, morphological, morphometrical, karyological and detailed pollen morphology of Ebenus haussknechtii endemic to Turkey was studied for the first time. In the morphologic study, some morphological and morphometrical features of the plant were observed and compared with the published findings in the Flora of Turkey. Karyogram and idiograms of the plant were also prepared. The chromosome number of E. haussknechtii was determined as 2n=14 and haploid karyotype formula 5m+1sm+1M. Metaphase chromosome length ranged from 2.16 to 1.93μm and the total haploid chromosome length was 17.90μm. The results of the light microscope investigation of the pollen revealed that the pollen grains were radially symmetrical, isopolar, tricolpate and prolate. Measurement of the reticulum heterobrachate indicated their ornamentation to be reticulate.

English

  The Silene species are annual, biennial or perennial herbs mainly distributed in the northern hemisphere, Europe, Asia and northern Africa. The section, Inflatae Boiss., is the smallest section of the genus containing three species and four subspecies in Iran, out of which one subspecies is endemic with very restricted distribution in the western and northern regions. Studies on seed morphology with scanning electron microscope (SEM) have revealed taxonomically useful micro-characters. The present study was performed to study morphological and micromorphological features in seven Silene species and subspecies in the sect Auriculatae and Inflatae growing in Iran, to study their intraspecific variations and to find out if such data can be used in taxonomy of the genus. The grouping obtained by unweighted pair group method with arithmetic mean (UPGMA) dendrogram separated the species of the section Inflataefrom the species of the section Auriculatae. Siahbishe population of Silene vulgarisdiffered in morphological characters and was placed some distance from the other studied populations. It also had the highest values of total haploid chromosome length (50.51 µM), size of the longest chromosome, (5.42 µM), size of the shortest chromosome (2.88 µM) and the mean chromosome length (4.21 µM). Therefore morphological differences of this population may be related to its higher total chromosome length (genome size), compared to those of other populations studied. We also suggested that the Siahbishe population to be considered as a new variety ofS. vulgaris, based on both morphological and cytological grounds. The seed type in both section are symmetrical reniform, asymmetric reniform and rounded-reniform. In the sect. Auriculate, the length of seed ranged from 1.22 to 2.23 mm, while the size of seed width ranged from 0.86 to 1.38 mm. In the sect. Inflatae, the length of seed ranged from 1.30 to 1.86 mm and the seed width ranged from 0.80 to 1.42 mm. These two sections differed in some other seed characteristics which are discussed.   Key words: Morphometry, taxonomy, seed characteristics, Silene.

Chromosome and pollen morphology of the rare endemic <i>Centaurae lycopifolia</i> Boiss. & Kotschy

Chromosome and pollen morphology of Centaurea lycopifolia Boiss. & Kotschy were studied. The chromosome number is 2n = 34 with haploid karyotype formula 9m + 9sm. Metaphase chromosome length ranging from 6.16 to 2.23 μm and the total haploid chromosome length was 65, 85 μm. The light and scanning electron microscope investigations revealed spheroidal-subprolate, the amb triangular and tricolporatae pollens in the taxon. Exine ornamentation was tectatae and microechinate-scabrate. Key words: Centaurea lycopifolia; Chromosome; Pollen morphology; Endemic; Turkey DOI: 10.3329/bjb.v39i2.7484 Bangladesh J. Bot. 39(2): 223-228, 2010 (December)

Giemsa staining and fluorescent chromosome banding in someVitisL. species

Giemsa staining technique and fl uorescent chromosome banding with CMA 3 and DAPI were applied to the mitotic chromosomes of Vitis champinii, V. cinerea, V. girdiana, V. labrusca, V. rotundifolia, V. rupestris and V. vinifera for the purpose of chromosome measurement and constitutive heterochromatin characterization at the cytochemical level, respectively. Both fl uorescent CMA and conventional Giemsa staining constituted a valuable tool for chromosome characterization. Karyomorphometric data obtained after Giemsa staining allowed for an average ideogram and karyotype formulae based on chromosome length for the species. V. champinii and V. girdiana distinguished from the other fi ve species by means of the total haploid chromosome length, by the longest chromosome length and by the average chromosome length. The seven grape species have moderate chromosome asymmetry values and were classifi ed on 2A Stebbins' category. Positive CMA bands were seen in all species. V. girdiana distinguished from the other species solely by the presence of two CMA + bands, while V. champinii, V. cinerea, V. labrusca, V. rotundifolia and V. rupestris had four bands. V. vinifera showed chromosome heteromorphism for CMA bands. No clearly visible DAPI + band was seen in the species. According to the present observations, it seems that the evolutionary process of speciation involving North American and European Euvitis species studied, resulted in some discrete changes in chromosome measurements and also in heterochromatin base composition of at least one species. These data enlarge the chromosomal information of the genus Vitis and make possible further comparative studies into the Vitaceae family.

Karyotype analysis of the yellowtail kingfishSeriola lalandi lalandi(Perciformes: Carangidae) from South Australia

The karyotype and chromosomal characteristics of the yellowtail kingfish Seriola lalandi lalandi were investigated by examining metaphase spreads from kidney cells of 4-month-old fish artificially bred using wild-captured broodstock from the coast of South Australia. A total of 80 mitotic metaphases from 10 individual fish were analysed, with 52 spreads having a mode of 2n=48 chromosomes, representing 65% of the metaphases observed. The diploid consisted of two metacentric, two submetacentric, six subtelocentric and 38 telocentric chromosomes, with the fundamental number of chromosome arms being 52. The total haploid chromosome length was approximately 44.412 μm. This study shows that the karyotype of S. lalandi lalandi differs from those reported previously for other Seriola species in having one pair of metacentric chromosomes.

A Cytogenetic Study of Seven Tea Clones [Camellia sinensis (L.) 0. Kuntze|

Karyotype analyses in seven cultivated clones (cv. T78, T383, TV30, HV39, TecnAli17/1/54, TV29, und UPASI-26) of tea (Camellia sinensis) are investigated for their cytogenetic characterization. Karyotypes of the chromosomes (2n = 30) were grouped arbitrarily on the basis of their length and position of the centromere into four types (A-D). Centromeric index (F %). total centromeric index (TF %), disparity index (DI) and total haploid chromosome length (TCL) were calculated. Chromosomes were found to be short to medium in size varied in length from 1.24 μm to 4.20 μm. Karyotypes were gradate and asymmetric in nature with median to nearly submedium chromosome. On the basis karyotype analysis, varietal distinction can be marked to some extent.