Fluorochrome Banding Research Articles

Chromosomal Characterization of Five Medicinally Significant Phyllanthus Species in Bangladesh by DNA Base-Specific Fluorochrome Banding Technique

ABSTRACT Five Phyllanthus species were characterized using a fluorochrome chromosome banding technique with CMA and DAPI. This genus displayed a range of somatic chromosomal counts, including 2n = 2x = 26 (diploid) in P. acidus, P. niruri, and P. reticulatus; 2n = 6x = 48 (hexaploid) in P. urinaria; and 2n = 10x = 100 (decaploid) in P. emblica (wild and cultivated varieties), which exhibited a multi-basic chromosome number. The centromeric and terminal regions of the chromosomes contained most of the CMA and DAPI bands, indicating that GC- and AT-rich repeats had accumulated in these locations. The diversity based on the heterochromatin distribution patterns made it possible to use the CMA and DAPI banding approaches to analyze and characterize these five Phyllanthus species.

Chromosomal characterization mediated by karyomorphological analysis and differential banding pattern in fenugreek (Trigonella foenum-graecum L.): a neglected legume

Fenugreek or Trigonella foenum-graecum L. is a commercially important yet neglected crop of the family Fabaceae, with potent medicinal applications, and can treat several diseases as well. Conventional breeding studies for higher yields of commercial crops largely depend on chromosomal information of the particular species. Despite a number of cytological research being conducted on T. foenum-graecum, a complete characterization of its chromosomes has not been achieved due to the limitations of traditional karyotype analysis methods. A range of chromosomal markers are advantageous to characterize at full extent and identify individual chromosomes rather than relying on only physical metrics. Thus, in this study, in addition to giemsa staining, other approaches like fluorochrome and silver staining were used for the precise karyomorphological analysis of this species. Enzyme maceration and air drying (EMA) based fluorochrome banding with GC-specific stain Chromomycin A3 (CMA), and AT-specific stain 4’,6-diamidino-2-phenylindole (DAPI) applied for the first time for chromosome characterization. The results showed 2n = 16 chromosomes in metaphase cells, with karyotype formula of 2m+6sm. The unique banding pattern observed in the CMA/DAPI and AgNOR staining highlights the AT and GC-rich regions as well as the nucleolar organizer regions (NORs). All this crucial information can further assist in conducting breeding studies of more precision with simultaneously encouraging similar studies that need to be done in other unexploited species of importance.

First genome size assessment and fluorochrome chromosome banding in Argania spinosa (L.) Skeels (Sapotaceae)

ABSTRACT Argania is a monotypic genus belonging to the family Sapotaceae and comprising the only species Argania spinosa. This taxon, endemic to southern Morocco (northern Africa), is important in arid lands. It has a high pastoral value, numerous traditional uses, and it is an important industrial crop for food and cosmetics. A few chromosome counts are available for the species but to date, there is no information on its genome size. Apart from being a parameter useful in many aspects of plant systematic and evolutionary biology, knowing the nuclear DNA amount is a pre-requisite to any genome-sequencing program. In this paper, we present for the first time data on the nuclear DNA content in Argania spinosa, from two populations, and we confirm its chromosome number. Genome size was estimated as 2C = 1.48 pg (1C = 723.72 Mbp) in both studied accessions, revealing a small genome. The chromosome count (2n = 20) revealed that the species has the lowest basic chromosome number (x = 10) in the Sapotaceae, and suggests a descending dysploidy process in the family. The first morphological characterisation of Argania spinosa’s karyotype is presented here. In addition, fluorochrome banding, performed with chromomycin A3 and DAPI, showed the absence of AT-rich regions and the presence of GC-rich regions located in three chromosome pairs, bringing the first molecular cytogenetic data in the genus.

Comparative cytogenetic study of Plantago species

Plantago is a large genus with a worldwide distribution characterized by three basic sets, x = 6 is the most common and is considered the ancestral set from which x = 5 and x = 4 derived following mechanisms of descending dysploidy. Advanced molecular cytogenetic methods are important for understanding evolutionary relationships but in Plantago their use has been rather limited. In this study the karyotypes of Plantago lanceolata L. (2n = 12), Plantago major L. (2n = 12) and Plantago coronopus L. (2n = 10) were characterized by using rDNA FISH, GISH, fluorochrome banding and chromosome morphology to obtain markers useful for evaluating their genomic affinity. The rDNA FISH mapping produced three distinct patterns but with evident similarities such as the chromosome position of 45S rDNA sites and the colocalization of 45S and 5S rDNA. Reciprocal GISH showed a low level of genome affinity between P. lanceolata and P. major and a total absence of homology between them and P. coronopus. This result supports the exclusion of the 2n = 12 species as possible ancestors of P. coronopus. This study confirms that a systematic use of in situ hybridization techniques, and in particular GISH, provide valid information for understanding the origin of species and can resolve many taxonomic and phylogenetic problematics.

Comparative Cytogenetics and Fluorescent Chromosome Banding in Five Indian Species of Dipcadi Medik

The genus Dipcadi Medik. (Subfamily: Scilloideae) has a narrow distribution in India and several overlapping morphological traits make the genus taxonomically challenging at the species level. Cytogenetic characterization can provide additional taxonomic data and can be used to evaluate genetic diversity at the species level. We have accomplished comparative karyotype analysis and fluorescence banding patterns using 4′-6-Diamidino-2-phenylindole (DAPI) and Chromomycin A3 (CMA) in five Indian species for the first time. The karyotypes of D. concanense and D. goaense exhibited similar fluorochrome banding profiles. However, D. montanum, D. ursulae and D. erythraeum differ distinctly in their karyotypes. In all taxa, CMA+ve/DAPI−ve or DAPI0 (GC-rich) constitutive heterochromatin was located at the constriction region or terminal satellite of the nucleolar chromosome. DAPI+ve/CMA−ve or CMA0 (AT-rich) heterochromatin dominates in D. montanum, D. ursulae and D. erythraeum. However, D. erythraeum shows a distinct variation in fluorochrome banding pattern from all other species. The distribution of CMA and DAPI bands is a reflection of heterochromatin composition and variations acquired by different species. This characterization can be used to assess phylogenetic relationships in the understudied genus Dipcadi and may serve as a basis for other genomic analyses and evolutionary studies.

Comparative karyotype analysis of eight Cucurbitaceae crops using fluorochrome banding and 45S rDNA-FISH.

To have an insight into the karyotype variation of eight Cucurbitaceae crops including Cucumissativus Linnaeus, 1753, Cucumismelo Linnaeus, 1753, Citrulluslanatus (Thunberg, 1794) Matsumura et Nakai, 1916, Benincasahispida (Thunberg, 1784) Cogniaux, 1881, Momordicacharantia Linnaeus, 1753, Luffacylindrica (Linnaeus, 1753) Roemer, 1846, Lagenariasicerariavar.hispida (Thunberg, 1783) Hara, 1948 and Cucurbitamoschata Duchesne ex Poiret, 1819, well morphologically differentiated mitotic metaphase chromosomes were prepared using the enzymatic maceration and flame-drying method, and the chromosomal distribution of heterochromatin and 18S-5.8S-26S rRNA genes (45S rDNA) was investigated using sequential combined PI and DAPI (CPD) staining and fluorescence in situ hybridization (FISH) with 45S rDNA probe. Detailed karyotypes were established using the dataset of chromosome measurements, fluorochrome bands and rDNA FISH signals. Four karyotype asymmetry indices, CVCI, CVCL, MCA and Stebbins' category, were measured to elucidate the karyological relationships among species. All the species studied had symmetrical karyotypes composed of metacentric and submetacentric or only metacentric chromosomes, but their karyotype structure can be discriminated by the scatter plot of MCA vs. CVCL. The karyological relationships among these species revealed by PCoA based on x, 2n, TCL, MCA, CVCL and CVCI was basically in agreement with the phylogenetic relationships revealed by DNA sequences. CPD staining revealed all 45S rDNA sites in all species, (peri)centromeric GC-rich heterochromatin in C.sativus, C.melo, C.lanatus, M.charantia and L.cylindrica, terminal GC-rich heterochromatin in C.sativus. DAPI counterstaining after FISH revealed pericentromeric DAPI+ heterochromatin in C.moschata. rDNA FISH detected two 45S loci in five species and five 45S loci in three species. Among these 45S loci, most were located at the terminals of chromosome arms, and a few in the proximal regions. In C.sativus, individual chromosomes can be precisely distinguished by the CPD band and 45S rDNA signal patterns, providing an easy method for chromosome identification of cucumber. The genome differentiation among these species was discussed in terms of genome size, heterochromatin, 45S rDNA site, and karyotype asymmetry based on the data of this study and previous reports.

Preparation of Mitotic Chromosomes with the Squash Technique.

Plant chromosomes are usually obtained from meristematic tissue of active root tips through the conventional squash method. Nevertheless, cytogenetic work usually implies a great effort and some modifications of standard procedures need to be evaluated. In this chapter, we describe our outline for handling chromosomes using the squash method. By using these protocols, high-quality chromosome spreads are obtained, which allow chromosome counting, building karyotypes, and assessing chromosomal landmarks, and enable genome mapping by fluorochrome banding and in situ hybridization techniques.

CHROMOSOMIC STUDIES IN ZEPHYRANTHES CITRINA BAKER (AMARYLLIDACEAE), A POLYPLOID ORNAMENTAL

Zephyranthes citrina is an ornamental American bulbous plant used as an ornamental garden crop for the aesthetic qualities of its yellow perigonium. The objective of this work was to characterize the species by classical chromosome staining and fluorochrome banding. A sporophytic chromosome number of 2n=8x=48 chromosomes was observed, being the karyotypic formula 20 m + 26 sm + 2 st. Satellites were detected in the short arm of metacentric chromosomes 8, 9, 11 and 12, which colocalized with constitutive heterochromatin CMA+/DAPI-/0 bands. The karyotype comprised chromosome pairs with terminal constitutive heterochromatin bands that included satellites and heteromorphic clusters indicating that it is an allooctoploid. These results will be used as a tool for monitoring genetic improvement, in interspecific crosses and its progenies and in biotechnological procedures by in vitro culture. Key words: constitutive heterochromatin, chromosome banding, bulbous, plant genetic resources, karyotype

Analysis of CMA-DAPI bands and preparation of fluorescent karyotypes in thirty Indian cultivars of Lens culinaris

India holds a significant rank in production and consumption of the age old protein rich crop Lentil with only one cultivated species and a large number of phenotypically similar cultivars. The need for a reliable and cost effective method of genetic characterization to unravel differences within the Lentil cultivars was felt. The present paper adopted EMA based chromosome preparation followed by staining with two contrasting fluorochromes dyes CMA and DAPI that bind directly to GC and AT rich heterochromatic segments on chromosomes. Analysis of fluorochrome banding pattern furnished a comparative account of genetic diversity within the cultivars that could not be achieved by traditional karyotyping. The marker pair of nucleolar chromosomes (4th and 3rd, majorly) occupied a pivotal position to intensify differences between cultivars in terms of banding patterns around secondary constrictions, suggestive of yet unknown variation in heterochromatin composition. Our study has strengthened genetic background and relationships of Lentil cultivars. We observed certain types of unusual fluorochrome bands that put forward the exclusivity of Indian germplasm and have questioned the mainstream heterochromatin elements of plant chromosomes captured by CMA-DAPI stains. The comprehensive fluorescent karyotypes of 30 L. culinaris cultivars prepared for the first time, serve as an archetype for the benefit of future breeding programmes in any Indian crop.

Molecular Cytogenetics (Fluorescence In Situ Hybridization - FISH and Fluorochrome Banding): Resolving Species Relationships and Genome Organization.

Fluorochrome banding (chromomycin, Hoechst, and DAPI) and fluorescence in situ hybridization (FISH) are excellent molecular cytogenetic tools providing various possibilities in the study of chromosomal evolution and genome organization. The constitutive heterochromatin and rRNA genes are the most widely used FISH markers. The rDNA is organized into two distinct gene families (18S-5.8S-26S and 5S) whose number and location vary within the complex of closely related species. Therefore, they are widely used as chromosomal landmarks to provide valuable evidence concerning genome evolution at chromosomal levels.

Cytogenetic characterization, nuclear genome size, and pollen morphology of some Hedysarum L. taxa (Fabaceae) from Algeria, with emphasis on the origin of H. perrauderianum Coss. & Durieu

Four spontaneous diploid taxa (2n = 2x = 16 chromosomes) of the genus Hedysarum L. were studied for the first time using molecular cytogenetic approach and a tetraploid one as an additional comparative control. This study follows the work undertaken on this genus as part of the preservation and valorization of fodder and pastoral phytogenetic resources in Algeria. Fluorescent in situ hybridization (FISH) results revealed the same number of 35S rDNA loci for all diploid taxa, but differences in the number and position of 5S ribosomal genes. Chromomycin fluorochrome banding displayed that all chromomycin positive bands (GC-rich heterochromatin) were colocalized with rDNA signals. 2C DNA values (genome size), estimated by flow cytometry, indicated greater than two-fold difference among diploid taxa where nuclear DNA amount ranged from 2C = 1.26 pg in H. carnosum Desf. to 2C = 3.36 pg in H. naudinianum Coss. Genome size of tetraploid H. perrauderianum Coss. & Durieu (2n = 4x = 32) also estimated for the first time, was 6.64 pg which is almost twice of the value of diploid H. naudinianum 2C = 3.36 pg. Palynological analysis by light microscopy shows two types of pollen grains: prolate and tricolpate for H. naudinianum and H. perrauderianum, subprolate and tricolporate for H. carnosum, H. spinosissimum subsp. capitatum (Desf.) Asch. & Gr. and H. pallidum Desf. These new data enrich the knowledge about relationships among these species and also allow proposing and discussing the possible origin of the tetraploid H. perrauderianum from the diploid H. naudinianum.

Unravelling the genetic diversity and phylogenetic relationships of Indian Capsicum through fluorescent banding

Hot chilli species of Capsicum are one of the most significant spice crops in India having several genetically distinct cultivars. The present study was targeted to upgrade chromosomal database of 15 cultivars belonging to C. annuum L., C. frutescens L. and C. chinense Jacq. EMA-based fluorochrome banding with GC-specific stain Chromomycin A3 (CMA) was elemental to reveal specialization in karyotypes that could not be traced out by Giemsa-stained preparations. CMA banding pattern was combined with karyomorphometric indices to statistically evaluate chromosomal relationship among the cultivars. The marker chromosome pairs 11 and 12 containing nucleolar CMA bands could be suggested as the evolutionary landmarks in ‘C. annuum complex’. We found direct correspondence between fruit morphotype variation and CMA banding pattern to demonstrate maximum genetic diversity within C. annuum, followed by C. frutescens while Bhut jolokia of C. chinense displayed genetic uniformity. UPGMA phenogram upheld distinct species separation, cultivar diversity and relationships within and among the species. Out of nine C. annuum cultivars, at least two cultivars showed some sort of genetic relationship with C. chinense, particularly the Ghee cultivar shares more proximity with C. chinense. The fluorescent karyotype database reliably symbolized uniqueness of Capsicum germplasm of India, especially from the NEH sector that grows Bhut jolokia. Our attempt is believed to complement genomic investigation in the popular and exotic chilli cultivars of India and interest breeders in search of alternative genetic resources.

Comparative molecular cytogenetic characterization of five wild Vigna species (Fabaceae).

To extend our knowledge on karyotype variation of the genus Vigna Savi, 1824, the chromosomal organization of rRNA genes and fluorochrome banding patterns of five wild Vigna species were studied. Sequential combined PI (propidium iodide) and DAPI (4',6-diamidino-2-phenylindole) (CPD) staining and fluorescence in situ hybridization (FISH) with 5S and 45S rDNA probes were used to analyze the karyotypes of V. luteola (Jacquin, 1771) Bentham, 1959, V. vexillata (Linnaeus, 1753) A. Richard, 1845, V. minima (Roxburgh, 1832) Ohwi & H. Ohashi, 1969, V. trilobata (Linnaeus, 1753) Verdcourt, 1968, and V. caracalla (Linnaeus, 1753) Verdcourt,1970. For further phylogenetic analysis, genomic in situ hybridization (GISH) with the genomic DNA of V. umbellata (Thunberg, 1794) Ohwi & H.Ohashi, 1969 onto the chromosomes of five wild Vigna species was also performed. Detailed karyotypes were established for the first time using chromosome measurements, fluorochrome bands, and rDNA-FISH signals. All species had chromosome number 2n = 2x = 22, and symmetrical karyotypes that composed of only metacentric or metacentric and submetacentric chromosomes. CPD staining revealed all 45S rDNA sites in the five species analyzed, (peri)centromeric GC-rich heterochromatin in V. luteola, V. trilobata and V. caracalla, interstitial GC-rich and pericentromeric AT-rich heterochromatin in V. caracalla. rDNA-FISH revealed two 5S loci in V. caracalla and one 5S locus in the other four species; one 45S locus in V. luteola and V. caracalla, two 45S loci in V. vexillata and V. trilobata, and five 45S loci in V. minima. The karyotypes of the studied species could be clearly distinguished by the karyotypic parameters, and the patterns of the fluorochrome bands and the rDNA sites, which revealed high interspecific variation among the five species. The V. umbellata genomic DNA probe produced weak signals in all proximal regions of V. luteola and all (peri)centromeric regions of V. trilobata. The combined data demonstrate that distinct genome differentiation has occurred among the five species during evolution. The phylogenetic relationships between the five wild species and related cultivated species of Vigna are discussed based on our present and previous molecular cytogenetic data.

Advances in the cytogenetics of Annonaceae, the case of Annona cherimola L.

Annonaceae represent the largest extant family among the early divergent angiosperms. Despite the long-standing interest in its evolutionary and taxonomic aspects, cytogenetic studies on this family remain extremely few even on economically important species. With this study, we realized a detailed characterization of the chromosomes of Annona cherimola (2n = 14) by a combination of in situ hybridization techniques, fluorochrome banding, and karyomorphological analysis. FISH revealed that 45S and 5S rDNA sites are co-localized in correspondence to the secondary constrictions of the SAT-chromosome pair. Some hypotheses on the organization of the linked 45S and 5S rDNA repeats have been made. FISH with Arabidopsis-type telomeric arrays demonstrated that the A. cherimola telomeres are constituted by TTTAGGG sequences and that they are exclusively localized at the extremities of chromosomes. An insight into the chromosome structure of A. cherimola was obtained by the self-GISH procedure which revealed highly repeated DNA sequences localized in the centromeric regions of all chromosomes. The correspondence of s-GISH signals with DAPI banding suggests that these sequences are the principal component of the centromeric heterochromatin of this species. The karyotype of A. cherimola here described is proposed as the basic reference karyotype for successive investigations in Annonaceae.

Karyotype Analysis from Aerial Roots of <i>Piper nigrum</i> Based on Giemsa and Fluorochrome Banding

Karyotype Analysis from Aerial Roots of <i>Piper nigrum</i> Based on Giemsa and Fluorochrome Banding

Differences in Karyotype and Fluorochrome Banding Patterns among Variations of <i>Trichosanthes cucumerina</i> with Different Fruit Size

Differences in Karyotype and Fluorochrome Banding Patterns among Variations of <i>Trichosanthes cucumerina</i> with Different Fruit Size

Molecular cytogenetic characterization and phylogenetic analysis of four Miscanthus species (Poaceae).

Chromosomes of four Miscanthus (Andersson, 1855) species including M. sinensis (Andersson, 1855), M. floridulus (Schumann & Lauterb, 1901), M. sacchariflorus (Hackel, 1882) and M. lutarioriparius (Chen & Renvoize, 2005) were analyzed using sequentially combined PI and DAPI (CPD) staining and fluorescence in situ hybridization (FISH) with 45S rDNA probe. To elucidate the phylogenetic relationship among the four Miscanthus species, the homology of repetitive sequences among the four species was analyzed by comparative genomic in situ hybridization (cGISH). Subsequently four Miscanthus species were clustered based on the internal transcribed spacer (ITS) of 45S rDNA. Molecular cytogenetic karyotypes of the four Miscanthus species were established for the first time using chromosome measurements, fluorochrome bands and 45S rDNA FISH signals, which will provide a cytogenetic tool for the identification of these four species. All the four have the karyotype formula of Miscanthus species, which is 2n = 2x = 38 = 34m(2SAT) + 4sm, and one pair of 45S rDNA sites. The latter were shown as strong red bands by CPD staining. A non-rDNA CPD band emerged in M. floridulus and some blue DAPI bands appeared in M. sinensis and M. floridulus. The hybridization signals of M. floridulus genomic DNA to the chromosomes of M. sinensis and M. lutarioriparius genomic DNA to the chromosomes of M. sacchariflorus were stronger and more evenly distributed than other combinations. Molecular phylogenetic trees showed that M. sinensis and M. floridulus were closest relatives, and M. sacchariflorus and M. lutarioriparius were also closely related. These findings were consistent with the phylogenetic relationships inferred from the cGISH patterns.

Cytogenetic studies in three diploid species of Andropogon (Andropogoneae), section Leptopogon

Abstract Karyotypes can provide a relevant information about relationships and evolutionary origin among species of the Andropogon genus. This paper presents the karyotype, C+ and DAPI/CMA3 banding and DNA content of three diploid (2n=20) species belonging to section Leptopogon: A. selloanus, A. macrothrix and A. gyrans. Karyotypes of the three diploid species are symmetrical. We propose a karyotype formulae (18m + 2sm) for each of them. The three species show a pair of metacentric chromosomes with a terminal secondary constriction on short arms. Fluorochrome banding revealed different constitutive heterochromatin patterns and CMA3+/DAPI¬ terminal bands related to the nucleolar organizer region in each species. Nuclear DNA content was estimated by flow cytometry ranged from 2.22 to 2.61 pg. FISH technique revealed that these three species have two 45S rDNA loci at the distal ends of the short arms of two metacentric chromosomes. We compare the genomes of the diploids A. selloanus, A. macrothrix and A. gyrans, and the triploid A. ternatus using GISH. These technique allowed us to confirm the hypotheses that the A. selloanus, A. macrothrix and A. gyrans constitute a homogeneous group that share a common S genome that comprises just one of the genomes in the triploid A. ternatus.

Karyotype analysis of eight cultivated Allium species

The karyotypes of Allium, a genus that comprises many crops and ornamental plants, are relatively poorly studied. To extend our knowledge on karyotype structure of the genus, the chromosomal organization of rRNA genes and CMA/DAPI bands was studied. Fluorescence in situ hybridization using 5S and 35S rDNA probes and banding methods (silver staining and CMA3/DAPI staining) were used to analyze the karyotypes of eight cultivated Allium L. species. Analyzed Allium taxa revealed three different basic chromosome numbers (x = 7, 8, 9) and three different ploidy levels (diploid, triploid, and tetraploid). The rDNA sites chromosomal organization is reported the first time for the six species (A. moly, A. oreophilum, A. karataviense, A. nigrum, A. sphaerocephalon, A. porrum). The Allium species that were analyzed showed a high level of interspecies polymorphism in the number and localization of the rDNA sites. The fluorescence in situ hybridization patterns of 35S rDNA sites were more polymorphic than those of the 5S rDNA in the diploid species. Several groups of similar chromosomes could be distinguished among the chromosomes that had rDNA sites in the polyploid species. Each of the groups had three chromosomes (triploid A. sphaerocephalon L.) or four chromosomes (tetraploid A. porrum L.) suggesting their autopolyploid origin. In the genomes of four of the analyzed species, only some of the 35S rDNA sites were transcriptionally active. Fluorochrome banding revealed that the CMA3+ bands were associated with the 35S rDNA sites in all of the species that were analyzed, except A. fistulosum L. in which positive CMA3+ bands were detected in the terminal position of all of the chromosome arms. The rDNA sequences, nucleolar organizer regions (NORs), and CMA/DAPI bands are very good chromosome markers that allowed to distinguished from two to five pairs of homologous chromosomes in analyzed Allium species. The karyotypes of the studied species could be clearly distinguished by the number and position of the rDNA sites, NORs, and CMA/DAPI bands, which revealed high interspecific differentiation among the taxa.

Cytogenetics of two Indian varieties of Momordica charantia L. (bittergourd)

Abstract Momordica charantia L.commonly known as bitter gourd is a widely cultivated cash crop in India with immense medicinal values. India has been one centre of diversification of two prominent taxonomic varieties viz. long-fruited variety, M. charantia var. charantia (MCC) and small-fruited variety, M. charantia var. muricata (MCM). Momordica species have long been known not to be amenable to conventional cytological techniques. After thorough technical standardization, karyotype variation between the two varieties as well as different populations of the same variety was compared and we primarily structured karyotypes of MCC and MCM populations that conformed to diploid count of 2n = 22 with slightly greater chromosome size in MCM (1.32μm–3.24 μm) than MCC (1.27μm–3.07 μm). Significant differences in genome size between MCC and MCM was also confirmed by flow cytometry for the first time in the two varieties of the species. Pronounced intraspecific dissimilarity in somatic chromosomes was established by EMA-Giemsa method revealing four nucleolar chromosomes in MCC populations and six nucleolar chromosomes in MCM populations. This difference in varieties was substantiated by fluorochrome banding which revealed four and six distal CMA+ve signals in MCC and MCM respectively. Detailed inter- and intra- karyomorphometric evaluation ascertained higher tendency of karyotype asymmetry in MCC. EMA-DAPI technique was applied for meiotic analysis in MCC (n = 11) and MCM (n = 11) populations providing indications of regular meiotic behavior. These results will benefit the classification, the genetic basis of domestication and the genome studies of this widely cultivated cash crop.