Diploid Level Research Articles

P1027 Application of analysis tools from Affymetrix on Eureka Genotyping Solution to provide accurate and automated animal genotypes

The BRLMM-P 2-dimensional clustering algorithm is used by mid- to high-plex microarrays from Affymetrix for genotyping single nucleotide polymorphisms (SNP) and insertion/deletions (indels). The algorithm has successfully been implemented across arrays designed to study many dozens of organisms. Its Bayesian step gives it the flexibility to automatically adapt to cluster patterns exhibited by diploid and various levels of allopolyploidy. BRLMMP also incorporates methods for accurately genotyping samples originating from normal and inbred populations. SNPolisher is a tool developed by Affymetrix to calculate SNP quality control metrics, such as call rate, cluster separation, cluster variation, and deviation from expected cluster position. These metrics are used to classify the SNPs into performance categories for downstream applications. Eureka Genotyping Solution is an affordable, low- to mid-plex, high-throughput genotyping assay that uses common next-generation sequencing (NGS) platforms for signal readout. It enables the detection of tens to thousands of genetic markers, which are increasingly in demand for routine animal agrigenomics testing. Using the tools developed by Affymetrix for genotyping high-density SNP microarrays to analyze the low-density Eureka genotyping panels will automate the genotyping process, produce highly accurate results, and allow researchers to migrate between Axiom and Eureka platforms seamlessly. The Eureka NGS read counts are appropriately scaled, normalized, and transformed to process genotyping in the BRLMM-P and SNPolisher framework. The BRLMM-P algorithm has been shown to work on both microarray intensity and NGS reads. Various Eureka genotyping panels are tested, including a bovine panel, for which BRLMM-P generates an average sample call rate of 99.9% and an average sample concordance of 99.5%.

Chromosomal variation in some members of Malvales Juss. from Rajasthan, India

The present paper deals with the meiotic study of 15 species belonging to 7 genera of 3 families of order Malvales i.e. Malvaceae, Sterculiaceae and Tiliaceae from different geographical areas of Rajasthan. Out of 15 species, intraspecific cytotypes at tetraploid and diploid level of Triumfetta rhomboidea has been reported for the first time. The chromosome numbers of 6 species i.e. Abutilon pannosum, Sida ovata, Sida rhombifolia, T. rhomboidea are reported for the first time from India. Whereas, chromosome studies on Melhania magnifolia have been worked out for the first time, also the occurrence of new cytotypes of Abutilon ramosum (2n = 42) are the first record in global context. Meiotic course is found to be abnormal in case of T. rhomboidea, A. pannosum and A. ramosum with the presence of laggards, chromatin bridges, unoriented bivalents and cytomixis, leading to the reduced pollen fertility and heterogenous sized pollen grains.

Chromosome counts and male meiosis in two species ofPleurospermumHoffm. (Apiaceae): additional comments on the cytogeographic pattern of the genus

Abstract Pleurospermum Hoffm. (Apiaceae), a widely spread, heterogeneous genus of complex and controversial taxonomy, is poorly known for chromosome number and meiotic details from the Indian subcontinent. In the current study, we examined male meiosis, chromosome counts, and pollen fertility in two species, P. candollii and P. govanianum from alpine areas of north-west Indian Himalaya. Both the species exist at diploid level (P. candollii, n = 11 or 2n = 22, P. govanianum, n = 9 or 2n = 18) with two different basic chromosome numbers, x = 9 and 11. Meiotic course in the majority of pollen mother cells (PMCs) is normal; however, few meiocytes showed the occurrence of chromatin transfer among themselves which resulted into the formation of hypoploid and hyperploid PMCs. In addition, some PMCs depicted associated irregularities such as laggards, and chromatin bridges during meiosis-I and II. Microsporogenesis was also observed to be abnormal, and was characterized by the presence of micronuclei in the spora...

Chromosome counts and karyotype analysis ofViburnumtaxa (Adoxaceae)

AbstractA cytological study was carried out on 16 taxa belonging to seven clades of Viburnum (Adoxaceae). Chromosome numbers of these 16 taxa were counted and karyotypes of 12 taxa were analyzed. Chromosome numbers of four species and karyotypes of nine taxa are new records. Three chromosome numbers 2n = 16, 18 and 32 of these 16 taxa were discovered, of which the corresponding basic chromosome number was x = 8 or 9. Most taxa showed relatively symmetrical karyotypes, while the well-known V. macrocephalum form. keteleeri, which has a long cultivation history and is culturally important in China, presented the most asymmetrical karyotype. Unweighted pair group method with arithmetic mean (UPGMA) cluster analysis of V. cylindricum and V. punctatum supports the recognized clades Coriacea and Punctata that were previously subsections of Megalotinus. The chromosomal pattern with few polyploids suggests that structural changes of karyotype at the diploid level may be the main trend in chromosomal evolution in V...

Synergistic effects of polyploidization and elicitation on biomass and hyoscyamine content in hairy roots of Datura stramonium

Description of the subject. The hyoscyamine, a tropane alkaloid, widely used in medicine, can be produced from Datura sp. (Solanaceae). However, its content in the spontaneous roots remains low; therefore, hairy roots (HRs) were envisaged as a potential alternative to improve its biosynthesis. The hairy roots are characterized by a good genetic stability and a rapid growth. Indeed, Datura stramonium HRs have widely been studied in the perspective of improving the yield of hyoscyamine. This study is part of this same perspective. Objectives. This paper aims to study the effects of polyploidization of HRs induced by colchicine in synergy with elicitation (with acetylsalicylic [ASA] or salicylic acids [SA]) on the hyoscyamine content in D. stramonium. Method. Colchicine was applied at different concentrations and periods, on a selected hairy root line (LDS) of D. stramonium obtained by infection with Agrobactrium rhizogenes strain A4. The selection of tetraploid HR lines was performed by the cytogenetic analysis using light microscopy. The effect of polyploidization and elicitation was studied on the biomass (dry weight) and hyoscyamine content of HRs. Results. The untreated HR line (control) shows a diploid level with 2n = 24 chromosomes. However, the HR lines treated with colchicine show, in most cases, an endoreduplication of their genetic material. The survival rate of endoreduplicated lines varies between 30% and 93%, depending on concentration and exposure time to colchicine. Moreover, the tetraploid HR line shows an increase in its biomass and hyoscyamine content in comparison to the diploid HR line (LDS). Further, elicitation of HRs by ASA or AS at the 10-4 M concentration causes a low decrease or increase in dry weight, respectively. However, the same treatments show a significant increase in the yield of hyoscyamine in elicited HR lines. Consequently, our work indicates that the combination of polyploidy and elicitation can lead to significant improvements in hyoscyamine biosynthesis and content due to their synergistic effects. Conclusions. Elicitation of tetraploid hairy root lines improves significantly their content of hyoscyamine.

Evidence of the occurrence of structural chromosome changes at the initial diploid diversification of the autopolyploid Turnera sidoides L. (Passifloraceae) complex.

Turnera sidoides is an autopolyploid complex of obligate outcrossing perennial herbs. It includes five subspecies and five morphotypes in which diploid to octoploid cytotypes were found. Based on phenetic analyses of the complex and karyotype data of polyploid cytotypes, it has been hypothesized that morphological and chromosome differentiation of T. sidoides occurred at the diploid level. To test this hypothesis, we present the first detailed chromosome analysis of diploid populations of three subspecies and four morphotypes. CMA(+)/DAPI(-) bands were restricted to secondary constrictions (except in the andino morphotype) and varied in number and position among taxa. By contrast, DAPI staining was uniform in all the materials investigated. The number and position of 45S rDNA loci were coincident with the CMA(+)/DAPI(-) bands associated with secondary constrictions. Only one pair of 5S rDNA loci was detected in all the taxa (except in subsp. holosericea), but its position was variable. The identified chromosome markers varied among the three subspecies analyzed, but they were more conserved among the morphotypes of subsp. pinnatifida. Cluster analysis of these chromosome markers supports the current taxonomic arrangement of diploids and demonstrates that structural chromosome changes would have led or accompanied the initial differentiation of T. sidoides at the diploid level.

Chromosome counts of some species of the genus Galium (Rubiaceae) from Iran

Data on the chromosome counts of ten taxa of the genus Galium are reported from northeastern Iran. Two basic chromosome numbers, i.e. x = 10 and x = 11, as well as three ploidy levels, i.e. 2x, 4x and 6x are reported. Both diploid and polyploidy levels are observed. Aneuploidy was only observed in G. aparine. The chromosome numbers of the following taxa are counted for the first time: G. diploprion, G. humifusum, G. nigricans with 2n = 22 and G. spurium subsp. ibicinum with 2n = 20. The new data are compared with previous karyological information, and are discussed. (© 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Comparison of Two Selection Methods for Tolerance to Acidic, Aluminum‐rich Soil in Alfalfa

ABSTRACTIn acid soils (pHwater <5), Al becomes toxic, affecting alfalfa (Medicago sativa L.) root growth and development. In the southeastern United States, Al toxicity and its associated deficiencies are the most significant factors limiting alfalfa production. This study aimed to compare genetic gain for acid or Al tolerance as assessed by seedling biomass production in acidic soil under greenhouse conditions using phenotypic recurrent selection with gridding (PRSG) and among and within family selection (AWFS) in ‘Bulldog 805’ and PRSG in the germplasm ‘Cultivated Alfalfa at the Diploid Level’ (CADL) for two cycles. Selection was based on aerial biomass production or visual score 60 d after germination in Al‐rich acidic (unlimed, UL) soil and limed soil. Cycles 0, 1, and 2 from each method and population were evaluated for their root and shoot dry weight (RDW and SDW) after 60 d in UL and limed soils. Unlimed/limed soil RDW and SDW ratios were computed. CADL did not respond to selection, probably because of the lack of initial variability for Al tolerance. Bulldog 805 selected in limed soil did not result in any improvement in limed or UL conditions but selection in UL soil improved performance in acidic soil after two cycles and did not negatively affect growth in limed soil. In Bulldog 805, PRSG had the largest response per cycle: over 20% over Cycle 0 (C0). Direct selection in UL soil was the best way to improve growth in acidic Al‐rich soils. These results need to be validated in the field.

Association of Phenotypic Traits with Ploidy and Genome Size in Annual Ryegrass

ABSTRACTAnnual ryegrass (Lolium multiflorum Lamarck) is planted annually on more than 1 million ha of pastures in the southeastern United States. The exact ploidy level and genome size of the annual ryegrass germplasm collection (USDA–ARS, Germplasm Resources Information Network, GRIN) are unknown and the future use of this germplasm relies on their determination. The study was conducted to (i) estimate the ploidy level and determine the DNA content of 139 accessions from the GRIN collection, 15 experimental lines, and 13 commercial cultivars through flow cytometry; and (ii) identify morphological and agronomic characteristics that could be used to differentiate diploid from tetraploid annual ryegrass. A total of 140 diploid and 27 tetraploid lines were successfully identified through flow cytometry. The average 2C DNA content was 6.13 ± 0.36 pg for the diploid lines and 12.30 ± 0.83 pg for the tetraploids. Diploid and tetraploid annual ryegrass showed significant differences for morphological and agronomic variables such as seed size, leaf width and length, guard cell size, plant height, tiller size, plant biomass, and seed head length, and all variables were significantly correlated with DNA content. The use of morphological and agronomic variables may guide the determination of ploidy when flow cytometry is not available. Ploidy level and genome size information will benefit those that request accessions from the GRIN system for specific studies at the diploid or tetraploid level in the species.

The striking and unexpected cytogenetic diversity of genus Tanacetum L. (Asteraceae): a cytometric and fluorescent in situ hybridisation study of Iranian taxa.

BackgroundAlthough karyologically well studied, the genus Tanacetum (Asteraceae) is poorly known from the perspective of molecular cytogenetics. The prevalence of polyploidy, including odd ploidy warranted an extensive cytogenetic study. We studied several species native to Iran, one of the most important centres of diversity of the genus. We aimed to characterise Tanacetum genomes through fluorochrome banding, fluorescent in situ hybridisation (FISH) of rRNA genes and the assessment of genome size by flow cytometry. We appraise the effect of polyploidy and evaluate the existence of intraspecific variation based on the number and distribution of GC-rich bands and rDNA loci. Finally, we infer ancestral genome size and other cytogenetic traits considering phylogenetic relationships within the genus.ResultsWe report first genome size (2C) estimates ranging from 3.84 to 24.87 pg representing about 11 % of those recognised for the genus. We found striking cytogenetic diversity both in the number of GC-rich bands and rDNA loci. There is variation even at the population level and some species have undergone massive heterochromatic or rDNA amplification. Certain morphometric data, such as pollen size or inflorescence architecture, bear some relationship with genome size. Reconstruction of ancestral genome size, number of CMA+ bands and number of rDNA loci show that ups and downs have occurred during the evolution of these traits, although genome size has mostly increased and the number of CMA+ bands and rDNA loci have decreased in present-day taxa compared with ancestral values.ConclusionsTanacetum genomes are highly unstable in the number of GC-rich bands and rDNA loci, although some patterns can be established at the diploid and tetraploid levels. In particular, aneuploid taxa and some odd ploidy species show greater cytogenetic instability than the rest of the genus. We have also confirmed a linked rDNA arrangement for all the studied Tanacetum species. The labile scenario found in Tanacetum proves that some cytogenetic features previously regarded as relatively constant, or even diagnostic, can display high variability, which is better interpreted within a phylogenetic context.Electronic supplementary materialThe online version of this article (doi:10.1186/s12870-015-0564-8) contains supplementary material, which is available to authorized users.

Germplasm resources for verticillium wilt resistance breeding and genetics in strawberry (Fragaria)

BACKGROUND: The fungal disease verticillium wilt has been recognized as an obstacle to strawberry production since its initial description in 1931. The full potential of genetic resistance as a solution to this problem has yet to be determined or realized. OBJECTIVE: Our investigations are concerned with defining new sources of resistance to verticillium wilt disease in cultivated and wild strawberry germplasm, and with advancing genetic studies on the basis of resistance/susceptibility. METHODS: We screened 23 diploid, 1 decaploid, and 26 octoploid Fragaria (strawberry) germplasm accessions and cultigens for response to root-dip inoculation with Verticillium dahliae isolate V1. Pedigree relationships of 10 studied cultigens were examined. Crosses were performed between resistant and susceptible accessions. RESULTS: Variability in inoculation response existed within and between species at diploid and octoploid levels. Very or moderately resistant accessions were found within each of three diploid and three octoploid species. Moderately or very susceptible accessions were documented within F. vesca and each octoploid species. Segregation for resistance/susceptibility was evident in progeny populations. CONCLUSIONS: The verticillium wilt resistance ratings reported here and discussed in relation to prior studies adds to the body of publically available knowledge about sources of wilt resistance and susceptibility in Fragaria germplasm.

Detecting reticulate relationships among diploid Leucanthemum Mill. (Compositae, Anthemideae) taxa using multilocus species tree reconstruction methods and AFLP fingerprinting

We examined the evolutionary history of the diploid representatives of the genus Leucanthemum Mill. (Compositae, Anthemideae), which constitutes an extensive polyploid complex comprising around 41 species with ploidy levels ranging from 2x to 22x. The inference of phylogenetic relationships even on the diploid level is complicated in this genus due to the overlay of hybridisation and incomplete lineage sorting processes leading to incongruence among gene trees based on nuclear and plastid sequence information. Species tree and network reconstructions were based on gene trees from nine low-copy nuclear markers and the concatenated sequence information for five intergenic spacer regions of the chloroplast genome, either sequenced by Roche 454 pyrosequencing techniques or traditional Sanger sequencing techniques. Additional phylogenetic information came from multi-locus AFLP-fingerprinting of representative individuals of all diploid taxa under study and the subsequent analysis of AFLP patterns with Bayesian clustering and network reconstruction methods. To distinguish between hybridisation and incomplete lineage sorting, we developed and utilized a new ‘hybrid index’ calculation for individual taxa of the data set, which was compared to a simulated null-distribution assuming the occurrence of incomplete lineage sorting alone for pinpointing taxa with a significant hybrid signal. As a result, two species groups with contrasting patterns of gene flow and/or hybrid speciation signals could be identified in the diploids of Leucanthemum: (a) an early-diverging stock of allopatrically distributed diploid species with a lack of evidence for recent hybridisation events among its members and (b) a more recently radiated taxon assemblage with morphologically less clearly circumscribed taxa and a pronounced signal of gene flow among lineages and several candidate taxa, for which a homoploid hybrid origin may be considered.

Gene expression dosage regulation in an allopolyploid fish.

How allopolyploids are able not only to cope but profit from their condition is a question that remains elusive, but is of great importance within the context of successful allopolyploid evolution. One outstanding example of successful allopolyploidy is the endemic Iberian cyprinid Squalius alburnoides. Previously, based on the evaluation of a few genes, it was reported that the transcription levels between diploid and triploid S. alburnoides were similar. If this phenomenon occurs on a full genomic scale, a wide functional ‘‘diploidization’’ could be related to the success of these polyploids. We generated RNA-seq data from whole juvenile fish and from adult livers, to perform the first comparative quantitative transcriptomic analysis between diploid and triploid individuals of a vertebrate allopolyploid. Together with an assay to estimate relative expression per cell, it was possible to infer the relative sizes of transcriptomes. This showed that diploid and triploid S. alburnoides hybrids have similar liver transcriptome sizes. This in turn made it valid to directly compare the S. alburnoides RNA-seq transcript data sets and obtain a profile of dosage responses across the S. alburnoides transcriptome. We found that 64% of transcripts in juveniles’ samples and 44% in liver samples differed less than twofold between diploid and triploid hybrids (similar expression). Yet, respectively 29% and 15% of transcripts presented accurate dosage compensation (PAA/PA expression ratio of 1 instead of 1.5). Therefore, an exact functional diploidization of the triploid genome does not occur, but a significant down regulation of gene expression in triploids was observed. However, for those genes with similar expression levels between diploids and triploids, expression is not globally strictly proportional to gene dosage nor is it set to a perfect diploid level. This quantitative expression flexibility may be a strong contributor to overcome the genomic shock, and be an immediate evolutionary advantage of allopolyploids.

Interspecific hybridisation within Buxus spp.

Breeding efforts within Buxus have been limited, despite the great morphological and genetic variation within this genus. To evaluate the possibilities for creating novel cultivars through interspecific hybridisation within Buxus, we have made over 7500 interspecific crosses involving Buxus harlandii Hance, Buxus sempervirens L., Buxus microphylla Sieb & Zucc, Buxus balearica Lam., Buxus colchica Pojark and Buxus henryi Mayr. Germination of the resulting interspecific seeds was between 0% and 47% for some cross combinations. In total 4750 interspecific F1 seedlings were obtained. The hybrid nature of most seedlings could be proven using AFLP markers or flow cytometry. As expected, crosses at diploid level or tetraploid level were efficient. Moreover, our results showed that interploidy crosses (diploid×tetraploid) were also efficient.This study is the first in-depth exploration of the possibilities of interspecific hybridisation within Buxus. These results may become a valuable tool to create new Buxus cultivars with desirable traits.

Reference gene selection for cross-species and cross-ploidy level comparisons in Chrysanthemum spp.

The establishment of a (set of) stably expressed reference gene(s) is required to normalize transcription data. Polyploidy is very common in the plant kingdom, but it is not necessarily the case that a reference gene which works well at the diploid level will also work well at the polyploid level. Here, ten candidate reference genes are compared in the context of gene transcription in the genus Chrysanthemum. The robustness of some, but not all, of these was shown to be high across ploidy levels. MTP (metalloprotease) and ACTIN (actin) were the most stable in diploid and tetraploid C. nankingense, while PSAA (photosynthesis-related plastid gene representing photosystem I) and EF-1α (elongation factor-1α) were the most stable in tetraploid and hexaploid C. zawadskii. EF-1α and PGK (phosphoglycerate kinase) was the best combination for the complete set of four taxa. These results suggest that when making cross-species comparison of transcript abundance involving different ploidy levels, care needs to be taken in the selection of reference gene(s).

Filling gaps with construction of a genetic linkage map in tetraploid roses.

Rose (Rosa sp.) is one of the most economically important ornamental crops worldwide. The present work contains a genetic linkage map for tetraploid roses that was constructed from an F1 segregation population using AFLPs and SSRs on 189 individuals. The preliminary ‘Yunzheng Xiawei’ and ‘Sun City’ maps consisted of 298 and 255 markers arranged into 26 and 32 linkage groups, respectively. The recombined parental maps covered 737 and 752 cM of the genome, respectively. The integrated linkage map was composed of 295 polymorphic markers that spanned 874 cM, and it had a mean intermarker distance of 2.9 cM. In addition, a set of newly developed EST-SSRs that are distributed evenly throughout the mapping population were released. The work identified 67 anchoring points that came from 43 common SSRs. The results that were produced from a large number of individuals (189) and polymorphic SSRs (242) will enhance the ability to construct higher density consensus maps with the available diploid level rose maps, and they will definitely serve as a tool for accurate QTL detection and marker assisted selection.

Meiotic abnormalities in <i>Ageratum conyzoides</i> from hot desert of India (Rajasthan)

Presently, 14 populations of Ageratum conyzoides L. have been meiotically studied from different geographical regions of Rajasthan. Of which, five populations are at tetraploid level (2n=40) and the remaining nine at diploid level (2n=20). Morphologically, populations vary on the basis of the floret color (from light purple to white). Meiosis of five populations i.e., three diploid cytotypes and two tetraploid cytotypes exhibit abnormalities like, early disjunction of bivalents, univalents, laggards, chromatin bridges, abnormal microsporogenesis and low pollen fertility.

Impaired Male Meiosis and Multiple Associations in <i>Chaerophyllum</i> L. from the Western Himalayas, India

We present a cytological study of species of the genus Chaerophyllum L. (Apiaceae) by analysing five accessions covering three species from the Western Himalayas, India. The species are collected and studied for detailed male meiosis, multiple associations and pollen fertility. All the studied species exist at diploid level (based on x=11), and show a meiotic chromosome count of 2n=22 at diakinesis and metaphase-I, and regular chromosome distributions at anaphases-I/II. C. aromaticum is reported for the first time from India and found to be in conformity with the earlier reports of 2n=22 from outside India. Out of three studied species, two (C. acuminatum and C. aromaticum) showed the presence of multiple chromosomal associations at metaphase-I of meiosis-I. The paper herein discusses for the first time the occurrence of multiple associations in these species. The course of meiosis in all studied species shows impaired meiotic course in the form of cytomixis, chromatin stickiness, laggards and chromatin bridges. Abnormal microsporogenesis results in heterogeneous-sized pollen grains and reduced pollen fertility.

Gonad Development in Triploid Ornamental Koi Carp and Results of Crossing Triploid Females with Diploid Males

AbstractGonad development in 4‐year‐old triploid and diploid ornamental koi, a variant of Common Carp Cyprinus carpio, from corresponding heat‐shocked and control progenies was investigated. Diploid males were normally mature. Triploid males from heat‐shocked progeny demonstrated development of testes typical for triploid fish; triploid males did not release sperm and their testes had a pinkish color and were significantly reduced in size. Diploid females were normally mature and their gonadosomatic indices (GSIs) varied from 7.5% to 30.7% and the mean value was 21.3%. Triploid females had unexpectedly well‐developed ovaries, which were filled with fully grown oocytes; their GSIs varied from 4.2% to 30.1% and the the mean value was 17.0%. Four triploid koi females released large quantities (from 260,000 to 394,500 eggs per female) of ovulated eggs after hormonal injection. Eggs from triploid females were fertilized with sperm from normal diploid koi males. Mass mortality of hatched larvae occurred at the swim‐up stage, but about 32,000 swim‐up larvae were obtained and stocked for further rearing. A total of 248 juveniles (or less than 1% from the number of stocked larvae) were collected from outdoor tanks. Ploidy analysis of juveniles (n = 110) showed that most of them were aneuploid with ploidy ranging from 2.3n to 2.9n with a mean value of 2.6n; two juveniles were diploid (2n). This shows that triploid koi females produced aneuploid eggs with a ploidy range from haploid to diploid level with the modal ploidy level around 1.5n, similar to the production of aneuploid spermatozoa observed earlier for triploid males in fish.

Cytogenetic study and pollen viability of three populations of Diplotaxis harra (Brassicaceae) in Iran

In this study, we examined the chromosome number, detailed male meiosis, microsporogenesis, pollen fertility and distribution of cytotypes of Diplotaxis harra (Forssk.) Boiss. This is the first cytogenetic report of the taxon. The two of the populations scored now from regions of the central showed aneuploid (x = 14) meiotic chromosome count and one of the populations studied from the existed at the diploid level (x = 13). It seems that the species with x = 14 are derived through aneuploid increase. The most prominent among these meiotic abnormalities was the chromatin stickiness which involved inter PMC and fragmented chromosome at different stages of meiosis. Consequently, these populations exhibited varying percentages of pollen sterility and pollen grains of smaller sizes. The aim of the present research was to study the male meiosis in detail and to find the impact of chromatin stickiness in inducing meiotic aberrations and their consequent effect on pollen fertility and pollen size, also to differentiate the individuals growing wild and also to find out the distribution patterns of different cytotypes in the Iran.