Number 2n Research Articles

Chromosome-level genome assembly of Phrynocephalus forsythii using third-generation DNA sequencing and Hi-C analysis.

Phrynocephalus forsythii is a viviparous sand lizard that endemic to the Tarim Basin with a broad altitudinal range of 872 to 3100 m. Such variation in altitude and ecological variables can offer an opportunity to uncover genetic mechanisms of ectothermic adaptation to extreme environments at high- and low-altitude. Furthermore, the evolutionary relationship of karyotype with two different chromosome numbers (2n=46 or 2n=48) in the Chinese Phrynocephalus is unclear. In this study, a chromosome-level reference genome of P. forsythii was assembled. The genome assembly size was 1.82 Gb with a contig N50 length of 46.22Mb, 20,194 protein-coding genes were predicted and 95.50% of these genes were annotated in functional public databases. After cluster contigs into chromosome level using Hi-C paired-end reads, we found that two chromosomes of P. forsythii were originated from one ancestral chromosome of species with 46 chromosomes. Comparative genomic analysis revealed that numerous characteristics associated with high- or low-altitude adaptation, including energy metabolism pathways, hypoxic adaptation and immune, exhibit rapid changes or show signals of positive selection in the P. forsythii genome. This genome provides an excellent genome resource for the study of the karyotypes evolution and ecological genomics of Phrynocephalus.

Irregularities in Meiotic Prophase I as Prerequisites for Reproductive Isolation in Experimental Hybrids Carrying Robertsonian Translocations

The basic causes of postzygotic isolation can be elucidated if gametogenesis is studied, which is a drastically different process in males and females. As a step toward clarifying this problem, we obtained an experimental inbred lineage of the eastern mole vole Ellobius tancrei, whose founder animals were animals with identical diploid numbers 2n = 50 but with different Robertsonian translocations (Rb), namely 2Rb4.12 and 2Rb9.13 in the female and 2Rb.2.18 and 2Rb5.9 in the male. Here, we analyzed strictly inbred hybrids (F1, fertile and F10, sterile) using immunocytochemical methods in order to study spermatocytes during the meiotic prophase I. Previously, the presence of trivalents was assumed to have no significant effect on spermatogenesis and fertility in hybrids, but we demonstrated that spermatogenesis might be disturbed due to the cumulative effects of the retarded synapses of Rb bivalents as well as trivalents and their associations with XX sex bivalents. Alterations in the number of gametes due to the described processes led to a decrease in reproductive capacity up to sterility and can be examined as a mechanism for reproductive isolation, thus starting speciation.

Centaurea dolopica (Asteraceae, Cardueae), a new species of section Acrocentron from Greece

Centaurea dolopica from Omvriaki area in Central Greece is described and illustrated as a species new to science based on morphological and molecular evidence. Detailed description of the new species, distribution, ecology, conservation status, as well as comparison with closely related species are provided. Individuals of Centaurea dolopica were also examined karyologically resulting to the chromosome number 2n = 2x = 22 accompanied by comprehensive karyotype analysis. Phylogenetic study including the new species and major representatives of Centaurea section Acrocentron was conducted using two nuclear markers (ITS, ETS). The results revealed the placement of Centaurea dolopica in the Greek-Aegean clade of the section in close evolutionary relationship with the members of the C. achaia group, corroborating the morphological and karyological data.

Contributions of species Rineloricaria pentamaculata (Loricariidae:Loricariinae) in a karyoevolutionary context

Species of Rineloricaria demonstrate an interesting evolutionary history from a cytogenetic point of view, due to the occurrence of extensive variation in diploid number (2n=36 -70 chromosomes), with Robertsonian rearrangements mostly responsible for this karyotypic diversity. In this study we present the karyotypic data for a population of Rineloricaria pentamaculata, collected in the Itiz stream, a tributary of the Paraná River Basin (Paraná, Brazil), which exhibited 2n=56 chromosomes distributed in 8m/sm+48st/a (number fundamental equal to 64) and simple NOR system revealed by fluorescent in situ hybridization (FISH) with 18S rDNA probe, silver nitrate and positive C band, located on the first submetacentric chromosome pair (pair 5). In addition, the NOR pair showed a size heteromorphism for this region, rich in GC composition (positive CMA3). Clusters of 5S rDNA were located in 14 chromosomes and the FISH with a telomeric probe was used to map possible evidence of chromosomal fusions, however, it showed only telomeric sites. These results corroborate the data for the species R. pentamaculata and the genus Rineloricaria, showing that they are similar to most of the populations analyzed. About the cytogenetic data of R. pentamaculata, we reaffirm that most populations were conserved, but in those with derived characteristics, Robertsonian chromosomal rearrangements probably contributed to the karyotypic evolution of the group.

Chromosome number of some Satureja species from Turkey

The genus Satureja belonging to the Lamiaceae family includes about 200 species, generally aromatic, distributed in the Mediterranean basin. In genus Satureja, the chromosomal data were reported from only 26 species. In this study, it is aimed to eliminate the deficiencies in the chromosomal data of Satureja species, which are distributed in Turkey, which is center of origin and diversity of the genus Satureja. It was reported only one chromosome number (2n = 30), the first report for chromosome numbers of three taxa, the same chromosome count (excluding B-chromosomes) with previous report in only one species, and the new chromosome number in only one species. In conclusion, this study presented new data into the chromosomal records of genus Satureja that might be useful for interpreting or understanding relationships among the species. In addition, dysploidy and polyploidy variations might probably have played an important role in speciation. In this regard, the results contributed to some missing data in Satureja cytotaxonomy.

Characterization of the chromosomes of sotol (Dasylirion cedrosanum Trel.) using cytogenetic banding techniques

Sotol (Dasylirion cedrosanum Trel.) is a perennial species with numerous grayish-to-green leaves that grow symmetrically from the base of the stem outward. Its inflorescences can measure up to 3 m in height and contain membranous bracts that enclose seeds. It is a species that has been scarcely studied at the cytogenetic level, with only one report available in the literature. In Mexico, it has economic importance because it is used to prepare the alcoholic beverage sotol. In the present work, the chromosomes of Dasylirion cedrosanum Trel. were obtained and analyzed using different cytogenetic banding techniques and morphometric analysis to construct the first karyotype for this species. Chromosomes were obtained by germinating plant seeds collected in the locality of Las Adjuntas, Santiago, Nuevo León, Mexico. Treatment with colchicine as an antimitotic was performed, followed by enzymatic treatment with pectinase and cellulase, to eliminate the cell walls. Chromosome slides were stained with Giemsa, GTG banding technique, CBW banding, and the 4’,6-diamidino-2-phenylindole fluorescence dye, and observed under a microscope. A chromosomal number 2n of 38 chromosomes, as previously reported, was confirmed. Using the different banding techniques, we observed that all chromosomes exhibited a submetacentric morphology with a fundamental number of 76, and it was possible to visualize the pattern of GTG and CBW bands; these findings are reported for the first time for this species. Morphometric analysis established that the average length of the chromosomes was between 5.09 and 9.84 mm.

Karyotype differentiation in the Nothobranchiusugandensis species group (Teleostei, Cyprinodontiformes), seasonal fishes from the east African inland plateau, in the context of phylogeny and biogeography.

The karyotype differentiation of the twelve known members of the Nothobranchiusugandensis Wildekamp, 1994 species group is reviewed and the karyotype composition of seven of its species is described herein for the first time using a conventional cytogenetic protocol. Changes in the architecture of eukaryotic genomes often have a major impact on processes underlying reproductive isolation, adaptation and diversification. African annual killifishes of the genus Nothobranchius Peters, 1868 (Teleostei: Nothobranchiidae), which are adapted to an extreme environment of ephemeral wetland pools in African savannahs, feature extensive karyotype evolution in small, isolated populations and thus are suitable models for studying the interplay between karyotype change and species evolution. The present investigation reveals a highly conserved diploid chromosome number (2n = 36) but a variable number of chromosomal arms (46-64) among members of the N.ugandensis species group, implying a significant role of pericentric inversions and/or other types of centromeric shift in the karyotype evolution of the group. When superimposed onto a phylogenetic tree based on molecular analyses of two mitochondrial genes the cytogenetic characteristics did not show any correlation with the phylogenetic relationships within the lineage. While karyotypes of many other Nothobranchius spp. studied to date diversified mainly via chromosome fusions and fissions, the N.ugandensis species group maintains stable 2n and the karyotype differentiation seems to be constrained to intrachromosomal rearrangements. Possible reasons for this difference in the trajectory of karyotype differentiation are discussed. While genetic drift seems to be a major factor in the fixation of chromosome rearrangements in Nothobranchius, future studies are needed to assess the impact of predicted multiple inversions on the genome evolution and species diversification within the N.ugandensis species group.

Strong intraspecific phylogenetic and karyotypic diversification in Isophya modestior (Orthoptera: Tettigoniidae: Phaneropterinae)

Abstract Isophya modestior (Orthoptera: Tettigoniidae) is a species distributed in central and south-eastern Europe, where its distribution is largely separated by two large rivers (Sava and Danube). Since previous studies on the song and morphology of the stridulatory file across its complete geographic range showed that the species is separated into two main groups, we decided to use phylogenetic and karyological analyses in order to evaluate the status of the previously analysed populations. Phylogenetic analyses showed the existence of two major clades within I. modestior with very high bootstrap values and posterior probabilities—Clade A: present on the Balkan Peninsula, Slovenia (Inner Carniola), Italy, Pannonian Serbia (Vršac Mts and Deronje) and Austria (Burgenland and Lower Austria); Clade B: present in Slovenia (Upper Carniola), Croatia and Austria (Carinthia), Pannonian Serbia (Fruška Gora Mt.) and Hungary. A comparison of chromosomes of 51 specimens revealed discrete differences between their karyotypes. The physical characteristics of the karyotypes included chromosome number (2n), sex chromosome (X) morphology and C-banding patterns. The standard chromosome complement of 50 specimens from different localities is characterized by 2n = 30 + X0 in males. In one male collected in Fruška Gora Mt. (Andrevlje), the chromosome number was reduced to 2n = 28 + neo-XY. Therefore, further cytogenetic studies involving larger samples, especially from Fruška Gora Mt., are needed in order to gain a more comprehensive view of the chromosome evolution in this group of Isophya species.

Small Body, Large Chromosomes: Centric Fusions Shaped the Karyotype of the Amazonian Miniature Fish Nannostomus anduzei (Characiformes, Lebiasinidae).

Miniature refers to species with extraordinarily small adult body size when adult and can be found within all major metazoan groups. It is considered that miniature species have experienced severe alteration of numerous morphological traits during evolution. For a variety of reasons, including severe labor concerns during collecting, chromosomal acquisition, and taxonomic issues, miniature fishes are neglected and understudied. Since some available studies indicate possible relationship between diploid chromosome number (2n) and body size in fishes, we aimed to study one of the smallest Neotropical fish Nannostomus anduzei (Teleostei, Characiformes, Lebiasinidae), using both conventional (Giemsa staining, C-banding) and molecular cytogenetic methods (FISH mapping of rDNAs, microsatellites, and telomeric sequences). Our research revealed that N. anduzei possesses one of the lowest diploid chromosome numbers (2n = 22) among teleost fishes, and its karyotype is entirely composed of large metacentric chromosomes. All chromosomes, except for pair number 11, showed an 18S rDNA signal in the pericentromeric region. 5S rDNA signals were detected in the pericentromeric regions of chromosome pair number 1 and 6, displaying synteny to 18S rDNA signals. Interstitial telomeric sites (ITS) were identified in the centromeric region of pairs 6 and 8, indicating that centric fusions played a significant role in karyotype evolution of studied species. Our study provides further evidence supporting the trend of diploid chromosome number reduction along with miniaturization of adult body size in fishes.

Sperberacris, a new Neotropical genus of Gomphocerinae (Orthoptera: Acridoidea: Acrididae) from State of Alagoas, Brazil with chromosome complement

Sperberacris, a new Neotropical genus of Amblytropidiini. Sperberacris muriciensis n. sp. (type species) from the municipality of Murici, State of Alagoas, Brazil is described. The new genus differs from other tribe congenera by the epiproct suboval, furculae divided into four long sclerotized lobes, cerci curved inward, apex truncated and sclerotized at the tip and convex bridge of the epiphallus with two large black sclerotized spots. The new species presents a diploid number of 2n = 23, X0♂/24, XX♀, and the karyotype is made up of telo/acrocentric chromosomes, with one dot-like B chromosome occurring in some nuclei. Morphological descriptions are provided along with illustrations emphasizing the most significant diagnostic features of external morphology and male genitalia. Information on type specimens, material examined, and distribution provided.

Cytogenetic Analysis of Seven Species of Gekkonid and Phyllodactylid Geckos.

Geckos (Gekkota), the species-rich clade of reptiles with more than 2200 currently recognized species, demonstrate a remarkable variability in diploid chromosome numbers (2n = 16-48) and mode of sex determination. However, only a small fraction of gekkotan species have been studied with cytogenetic methods. Here, we applied both conventional (karyotype reconstruction and C-banding) and molecular (fluorescence in situ hybridization with probes for rDNA loci and telomeric repeats) cytogenetic analyses in seven species of geckos, namely Blaesodactylus boivini, Chondrodactylus laevigatus, Gekko badenii, Gekko cf. lionotum, Hemidactylus sahgali, Homopholis wahlbergii (Gekkonidae) and Ptyodactylus togoensis (Phyllodactylidae), in order to provide further insights into the evolution of karyotypes in geckos. Our analysis revealed the presence of interstitial telomeric repeats in four species, but we were not able to conclude if they are remnants of previous chromosome rearrangements or were formed by an accumulation of telomeric-like satellite motifs. Even though sex chromosomes were previously identified in several species from the genera Hemidactylus and Gekko by cytogenetic and/or genomic methods, they were not detected by us in any examined species. Our examined species either have poorly differentiated sex chromosomes or, possibly, environmental sex determination. Future studies should explore the effect of temperature and conduct genome-wide analyses in order to identify the mode of sex determination in these species.

The Chromosome of Phalaenopsis spp. and Doritaenopsis sp. Hybrid Induced by Colchicine

One way to improve the genetic diversity of orchid plants is by polyploidization using the antimitotic compound colchicine. This research was conducted to determine the ploidy level in several types of hybrid orchids (Phalaenopsis spp. and Doritaenopsis sp.) that applied 1,000 mgL−1 colchicine and to obtain polyploidy orchid yields to improve the genetic diversity of orchid plants. This research was carried out on August 2021 - March 2022 in the Screen House Faculty of Agriculture Universitas Sebelas Maret and Integrated Laboratory Universitas Sebelas Maret. The method of this research uses squash preparation for chromosome analysis with the preparation materials used the meristematic flower bud of Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ which were not treated and has been treated with 1,000 mgL−1 colchicine. Orchid varieties that used as samples were three samples, then each sample had two treatments and was replication two times. There are twelve samples in all. The application of colchicine was made by wetting a cotton swab with 1 ml of colchicine solution in each treatment. Then the buds are wrapped with cotton and covered with carbon paper outside for two days. The results of this research showed that the Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ orchids which were treated with 1,000 mgL−1 colchicine each underwent polyploidization into tetraploid with the number of chromosomes 2n = 4x = 76. Phalaenopsis Shu Long ‘TS2904’, Phalaenopsis Chain Xen Moment, and Doritaenopsis Shu Long Purple Queen x OX King ‘3545’ have a relative length chromosome length, and have the same chromosome shape, namely metacentric.

Chromosome diversity in Buthidae and Chactidae scorpions from Brazilian fauna: Diploid number and distribution of repetitive DNA sequences.

In this work, we analyzed cytogenetically eight Chactidae and Buthidae, including the localization of repetitive DNA sequences. The chactids possess monocentric chromosomes and the highest diploid numbers (2n=50 in Brotheas amazonicus, 2n=36 in Chactopsis amazonica, 2n=30 in Neochactas sp.) when compared with buthids (2n=10 in Tityus bahiensis, 2n=14 in Tityus apiacas and Tityus metuendus, 2n=18 in Tityus aba, 2n=26 in Ischnotelson peruassu). The localization of rDNA genes and (TTAGG)n sequences exhibited a conserved pattern of two terminal/subterminal ribosomal cistrons and terminal telomere signals. However, the comparison between the data of C-banding, DAPI after FISH and Cot-DNA fraction indicated a variable quantity and distribution of these regions, as follow: (i) positive heterochromatin and Cot-DNA signals (B. amazonicus and I. peruassu), (ii) small blocks of heterochromatin with large Cot-DNA signals (T. metuendus), (iii) positive heterochromatic regions and absence of Cot-DNA signals (T. aba and T. apiacas), and (iv) negative heterochromatin and Cot-DNA signals (T. bahiensis). Therefore, our results revealed that there still is not a clear relation between quantity of heterochromatin and presence of monocentric or holocentric chromosomes and occurrence of chromosomal rearrangements, indicating that repetitive regions in scorpions must be analyzed using different cytogenetic approaches.

In Vitro Tetraploidization Towards Enhancement Of Charantin Biosynthesis In Momordica Charantia (L.)

A practical and reliable method for in vitro tetraploidization of Bitter Gourd [Momordica charantia (L.)] has been established to enhance the production of charantin. Shoot tip from in vitro-grown culture (2n = 22) were exposed to the anti-mitotic chemical, i.e., colchicine, at various concentrations (0, 0.01, 0.05, 0.1, 0.2 and 0.3% along with 2% DMSO) for 12, 24, 36, and 48 h. The treated explants were then incubated and proliferated on Murashige and Skoog (MS) medium fortified with 1.5 mg L-1 benzyladenine and 0.5 mg L-1 naphthalene acetic acid, followed by root induction in 1.0 mg L-1 indole-3 acetic acid enriched 1/2MS medium. Treatment of shoot tips with 0.1% colchicine for 24 h supported the highest tetraploid induction efficiency (33.56 ±0.22%). Morphological, stomatal, and cytological characteristics along with the secondary metabolite content of the in vitro tetraploids were compared to that of diploids. The recovered tetraploid plants possessed superior plant height, stem diameter, leaf size, and increased length and width of stomata but decreased stomatal frequency. The tetraploid plants demonstrated twice the chromosome number (2n = 4x = 44) in respect to diploids as confirmed through cytology, spectrophotometry and flow cytometry. Highperformance liquid chromatography showed 1.09 times enhancement of charantin content in tetraploid plants than that of diploid plants, signifying the prospective of this technique for the trade value improvement.

Chromosome numbers in 31 taxa of Asteraceae, Brassicaceae, Poaceae, Hypericaceae, Lamiaceae, Fabaceae and Plantaginaceae from wetlands of Hamadan region in Iran

In this study, we report the somatic chromosome numbers (2n) of 31 taxa belonging to Asteraceae, Brassicaceae, Poaceae, Hypericaceae, Lamiaceae, Fabaceae and Plantaginaceae families from wetlands of Hamadan region in Iran. The chromosome numbers of about half of these species have not been reported in the previous literature. Chromosome number of Ononis spinosa counted chromosomally for the first time at the world level and the chromosome numbers of Erigeron acer, Pulicaria dysenterica, Arctium lappa, Xanthium strumarium, X. spinosum, Barbarea plantaginea, Brachypodium sylvaticum, Polypogon fugax, Prunella vulgaris and Lathyrus chloranthus, are here reported for the first time from Iran. In all taxa 2n was 12, 14, 16, 18, 20, 24, 28, 30, 32 and 42, as a diploid, tetraploid and hexaploid levels. These newly available data are further compared with those previously published for the same or related species.

A comparative cytogenetic study of Hypsibarbusmalcolmi and H.wetmorei (Cyprinidae, Poropuntiini).

Cyprininae are a highly diversified but demonstrably monophyletic lineage of cypriniform fishes. Here, the karyotype and chromosomal characteristics of Hypsibarbusmalcolmi (Smith, 1945) and H.wetmorei (Smith, 1931) were examined using conventional, nucleolus organizing regions (NORs) and molecular cytogenetic protocols. The diploid chromosome number (2n) of H.malcolmi was 50, the fundamental number (FN) was equal to 62, and the karyotype displayed 8m + 4sm + 38a with NORs located at the centromeric and telomeric positions of the short arms of chromosome pairs 1 and 2, respectively. 2n of H.wetmorei was 50, FN 78, karyotype 14m + 14sm + 22a with the NORs at the telomeric position of the short arm of chromosome pair 2. 2n and FN in males and females were identical. Fluorescence in situ hybridization using different microsatellite motifs as probes also showed substantial genomic divergence between both studied species. In H.wetmorei, (CAG)n and (CAC)n microsatellites accumulated in the telomeric regions of all chromosomes, while in H.malcolmi, they had scattered signals on all chromosomes. Besides, the (GAA)n microsatellites were distributed along all chromosomes of H.malcolmi, but there was a strong hybridization pattern in the centromeric region of a single pair in H.wetmorei. These cytogenomic difference across the genomes of these Hypsibarbus Rainboth, 1996 species are markers for specific evolutionary differentiation within these two species.

Chromosomal Study on Selected Small Araneomorph Spiders from Brazil, Including the First Records in Palpimanidae and Theridiosomatidae (Araneae, Araneomorphae).

Among the 50,474 spider species, only 849 have chromosomal data available in the literature. Fifty spider families remain unknown from a cytogenetic perspective. The aim of this study was to analyze chromosomally selected araneomorph spiders from Brazil, to contribute to the cytotaxonomy and chromosome evolution of this group. The karyotypes of 12 species belonging to families Corinnidae, Linyphiidae, Oonopidae, Palpimanidae, Theridiidae, Theridiosomatidae, Trachelidae, and Zodariidae were analyzed, including the first chromosomal record for the first two families. Specimens (with the abdomen content partially exposed by perforation) were subjected to colchicine, hypotonization, and fixation. In most cases, the total content of the abdomen was used to prepare slides by spreading of cell suspension and subsequent Giemsa staining. The results were as follows: Cinetomorpha simplex Simon, 1892 (Oonopidae) 2n♂ = 9, X0; Neotrops sp. and Neoxyphinus termitophilus (Oonopidae), 2n♂ = 7, X0; Otiothops birabeni (Palpimanidae); Agyneta sp. (Linyphiidae), 2n♂ = 24, X1X20; Coleosoma floridanum, Thymoites sp.1 and Thymoites sp.2 (Theridiidae), 2n♂ = 22, X1X20; Naatlo sp. (Theridiosomatidae), 2n♂ = 30, X1X20; Orthobula sp. (Trachelidae) 2n♂ = 21, X0; Falconina sp. (Corinnidae), 2n♂ = 28, X1X20; Epicratinus sp. (Zodariidae) 2n♂ = 42, X1X20. The chromosomal morphology was determined for all the samples except for Oonopidae. Most species exhibited telocentric chromosomes, with the exception of Palpimanidae and Theridiosomatidae. The main findings: 1) support an hypothesis on ancestral karyotype of Zodariidae and Oonopidae; 2) reveal a relatively high chromosome number in Palpimanidae that supports an idea on relatively high ancestral chromosome number (2n♂ = 42) of entelegyne spiders (Palpimanoidea is sister group of entelegyne spiders); 3) show that the karyotype found in Theridiosomatidae is exceptional within the Araneoidea.

Chromosomal characterization of three species of Serrasalmini (Serrasalmidae: Characiformes).

The tribe Serrasalmini is a diverse group with paraphyletic genera and taxonomic uncertainties. Several studies have been carried out in this group of fish in order to understand this problem, including the cytogenetic approach. In this study, three species of a clade of Serrasalmini were characterized cytogenetically - Pristobrycon striolatus, Catoprion absconditus and Pygopristis denticulatus. The three species presented diploid number (2n) equal to 62 chromosomes, of one and two arms, with karyotypic formulas and species-specific fundamental numbers. Heterochromatin is centromeric and terminal (bi-telomeric) in most chromosomes, with a conspicuous interstitial block at pair 1 (m) in all three species. The nucleolar organizer regions were multiple and C-band positive, and their location was confirmed via 18S ribosomal DNA mapping; however, with additional sites. The 5S rDNA was located in interstitial region of long arm of pair 1 (m), in the three species (homeologous). Moreover, we observed synteny between 18S and 5S in the species C. absconditus and P. denticulatus, which, according to fiber-FISH, are interspersed. Thus, the maintenance of 2n (62) evidences the diversification of chromosomal formulas within the clade by non-Robertsonian rearrangements and reflects the paraphyly of the related species.

Variations in heterochromatin content reveal important polymorphisms for studies of genetic improvement in garlic (Allium sativum L.).

Allium sativum L. is an herb of the Alliaceae family with a specific taste and aroma and medicinal and nutraceutical properties that are widely marketed in several countries. Brazil is one of the largest importers of garlic in the world, despite of its production is restricted and limited to internal consumption. Thus, explore the genetic diversity of commercial garlic conserved at germplasm banks is essential to generate additional genetic information about its economically important crop. A suitable tool for this purpose is the cytogenetic characterisation of these accessions. This study aimed to characterise the cytogenetic diversity among seven accessions of garlic from a Germplasm Bank in Brazil. The karyotypes were obtained by conventional staining and with chromomycin A3 (CMA) and 4,6-diamidino-2-phenylindole (DAPI) fluorochromes. All accessions analysed showed chromosome number 2n = 16, karyotype formula 6M+2SM, symmetrical karyotypes, reticulate interphase nuclei, and chromosomes with uniform chromatin condensation from prophase to metaphase. The fluorochromes staining showed differences in the amount and distribution of heterochromatin along the chromosomes and between accessions studied. Based on the distribution pattern of these small polymorphisms, it was possible to separate the seven accessions into three groups. It was also possible to differentiate some of the accessions individually. One of the results obtained showed a heteromorphic distension of the nucleolar organiser region observed on the chromosome pairs 6 or 7 with peculiar characteristics. It was suggested for example, that the heteromorphic block of heterochromatin (CMA+++/DAPI-) on chromosome 6 of the "Branco Mineiro Piauí" accession can be used as a marker to identify this genotype or may be associated with some character of economic interest.

First constitutive heterochromatin characterization and Karyotype of white stork Ciconia ciconia (Aves: Ciconiidae).

The karyotype and constitutive heterochromatin pattern of the white stork Ciconia ciconia samples obtained from Manzala lake, Dimiaat, Egypt was described. Somatic cells of Ciconia ciconia samples have diploid number 2n= 68 chromosomes. Out of 68 chromosomes, 11 pairs including sex chromosomes were macrochromosomes and the remaining pairs were microchromosomes. Of the 11 macrochromosome pairs, no.1, 2, 4 and 5 were submetacentric and pairs no. 6, 7 and 8 were described as metacentric. In addition, the autosome pair no.3 was subtelocentric, while autosome pair no.9 was acrocentric. Also, the sex chromosome Z represents the fourth one in size and it was classified as submetacentric while, W chromosome appeared as medium size and was acrocentric. Furthermore, C-banding pattern (constitutive heterochromatin) revealed variation in their sizes and occurrence between macrochromosomes. Pairs no. 7 and 8 of autosomes exhibited unusual distribution of heterochromatin, where they appeared as entirely heterochromatic. This may be related to the origin of sex chromosomes Z and W. However, there is no sufficient evidence illustrate the appearance of entirely heterochromatic autosomes. Therefore, there is no available cytogenetic literature that describes the C-banding and karyotype of Ciconia Ciconia, so the results herein are important and may assist in cytogenetic study and evolutionary pattern of Ciconiiformes.