Genome size variation among natural populations of Brachypodium distachyon and B. hybridum collected from different regions of Turkey

Brachypodium distachyon (L) P.Beauv. is a model grass species that is useful for studying temperate cereal, forage, and energy crops. In this study we aimed to determine the genome size and species identity in the collections of the B. distachyon complex that included samples from 56 different locations in Turkey, applying chromosome counting and nuclear genome size evaluation by flow cytometry method (FCM). Moreover, the study examined whether diverse geographical conditions at the collecting sites influence the genome size. Chromosomal analysis revealed that the number of B. distachyon (x = 5, 2n = 10) genotypes was 48 and the number of B. hybridum (x = 5 + 10, 2n = 30) ones was 11. No genotypes of B. stacei were found. FCM analyses revealed that the minimum and maximum genome size of B. distachyon was 0.732 and 0.752 pg2C(-1), respectively. The mean genome size of B. distachyon was 0.743 pg2C(-1). The mean genome size of B. hybridum was 1.431 pg2C(-1) with the minimum 1.417 pg2C(-1) and maximum 1.451 pg2C(-1). Intraspecific variation in the genome size was identified for both species. It was determined that geographical origin (localization, altitude) had a statistically significant effect on genome size in B. distachyon. In addition, a negative correlation was found between altitude and genome size in this species. On the other hand, localization and altitude did not have any statistically significant effect on genome size in B. hybridum.Namik Kemal University Scientific Research Projects UnitNamik Kemal University [NKUBAP.00.24.DR.10.08]We would like to thank Namik Kemal University Scientific Research Projects Unit (Project No: NKUBAP.00.24.DR.10.08) for its financial support

Genome size and Giemsa C-banded karyotype of tetraploid \u3ci\u3eBromus ciliatus\u3c/i\u3e L.

Tetraploid Bromus ciliatus L. is a North American bromegrass that has been placed in the Pnigma section of Bromus. The objective of this study was to characterize the genome of tetraploid B. ciliatus by cytogenetic methods and compare it to the genomes of other species included in the section Pnigma. All the plants of the accession (USDA PI 232214) selected for chromosome counting were tetraploids (2n = 28). The mean 2C nuclear DNA content for tetraploid B. ciliatus was 19.13 ± 0.07 pg as determined by flow cytometry which is significantly greater than the tetraploid DNA content of B. inermis Leyss. (11.74 ± 0.16 pg). C-banding procedures were used to identify individual mitotic chromosomes and to develop a karyotype for B. ciliatus. The genome of the tetraploid B. ciliatus consisted of 16 median chromosomes, eight submedian chromosomes, and four chromosomes with satellites which included one pair with a large satellite and one pair with a small satellite. The general pattern of the distribution of constitutive heterochromatin in B. ciliatus was quite different than the other bromegrasses that have been analyzed to date. Except for two pairs of chromosomes, all chromosomes in tetraploid B. ciliatus had telomeric bands on one or both arms. Some of the chromosomes with telomeric bands had centromeric bands that were located at one or both sides of the centromere and intercalary bands which were generally absent in the other bromegrass species. It was possible to identify all chromosomes of tetraploid B. ciliatus and to match the pairs of homologous chromosomes by using chromosome lengths, arm length ratios and C-banding patterns. The results of this study indicate that tetraploid B. ciliatus has different genomes than the European species evaluated to date in the section Pnigma

Genome size and Giemsa C-banded karyotype of tetraploid \u3ci\u3eBromus ciliatus\u3c/i\u3e L.

Tetraploid Bromus ciliatus L. is a North American bromegrass that has been placed in the Pnigma section of Bromus. The objective of this study was to characterize the genome of tetraploid B. ciliatus by cytogenetic methods and compare it to the genomes of other species included in the section Pnigma. All the plants of the accession (USDA PI 232214) selected for chromosome counting were tetraploids (2n = 28). The mean 2C nuclear DNA content for tetraploid B. ciliatus was 19.13 ± 0.07 pg as determined by flow cytometry which is significantly greater than the tetraploid DNA content of B. inermis Leyss. (11.74 ± 0.16 pg). C-banding procedures were used to identify individual mitotic chromosomes and to develop a karyotype for B. ciliatus. The genome of the tetraploid B. ciliatus consisted of 16 median chromosomes, eight submedian chromosomes, and four chromosomes with satellites which included one pair with a large satellite and one pair with a small satellite. The general pattern of the distribution of constitutive heterochromatin in B. ciliatus was quite different than the other bromegrasses that have been analyzed to date. Except for two pairs of chromosomes, all chromosomes in tetraploid B. ciliatus had telomeric bands on one or both arms. Some of the chromosomes with telomeric bands had centromeric bands that were located at one or both sides of the centromere and intercalary bands which were generally absent in the other bromegrass species. It was possible to identify all chromosomes of tetraploid B. ciliatus and to match the pairs of homologous chromosomes by using chromosome lengths, arm length ratios and C-banding patterns. The results of this study indicate that tetraploid B. ciliatus has different genomes than the European species evaluated to date in the section Pnigma

Cytogenetic and Nuclear DNA Content Characterization of Diploid \u3ci\u3eBromus erectus\u3c/i\u3e and \u3ci\u3eBromus variegatus\u3c/i\u3e

Bromus erectus Huds. (erect brome) and B. variegatus M. Bieb. are Eurasian Bromus species that have been tentatively identified as potential progenitors of smooth bromegrass (B. inermis Leyss) which is the principal cultivated bromegrass in North America. The objective of this study was to characterize the genome of diploid accessions of B. erectus (2n = 2x = 14) and B. variegatus (2n = 2x = 14) using nuclear DNA content and cytogenetic analysis using Giemsa C-banding. The nuclear DNA content for B. erectus (6.19 ± 0.08 pg 2C-1) was less than that of B. variegatus (6.76 ± 0.05 pg 2C-1). These two species can be distinguished cytogenetically with the karyotypes that were developed. Complete karyotypes were not developed for both species because within species, multiple chromosomes were similar in size and C-banding. Both species had two pairs of chromosomes with satellites but the size of the satellites and the number and position of C-bands on these chromosomes differed between species. Bromus variegatus had five pairs of chromosomes with telomeric C-bands on both arms, while B. erectus had four pairs of chromosomes with a single telomeric band on the long arm and a single pair with telomeric bands on both arms. Comparison with the previously reported karyotypes and nuclear DNA contents for tetraploid and octaploid B. inermis suggest that if the diploid species B. erectus and B. variegatus were the donor species for these polyploids, significant evolutionary changes have occurred since the initial formation of these species including chromosome loss and re-arrangement

Karyotype and C-Banding Patterns of Mitotic Chromosomes in Diploid Bromegrass (\u3ci\u3eBromus riparius\u3c/i\u3e Rehm)

Previous cytogenetic studies of the genus Bromus L. were limited to chromosome counts and construction of karyotypes on the basis of Feulgen staining. Since the chromosomes of Bromus are similar in morphology, these karyotypes are of limited use for chromosome identification and genome analysis. The objectives of this study were to develop and evaluate a Giemsa C-banding procedure to use in identification of individual bromegrass chromosomes and to develop a karyotype for diploid Bromus riparius Rehm. (2n = 14; PI 440215). All chromosomes had one or more C-bands which were located mainly at telomeric regions. A group (I) of four pairs of chromosomes had telomeric bands on only one arm and could be differentiated. In this group, one pair had an interstitial C-band along with a telomeric band, one pair had a nucleolus organizer region (NOR) at a subtelomeric location on the short arm, and the other two pair could be distinguished by centromere location. The other group (II) of three pairs of chromosomes had telomeric bands on both arms. The unequivocal identification of specific chromosomes of Group II was not possible in all cells because of their similarity and differential condensation of chromosomes. Chromosomes of both groups were either metacentric or submetacentric. The total length of individual chromosomes ranged from 5.58 to 6.87 [micro]m and the arm ratios ranged from 1.02 to 1.5. The homologous chromosomes were paired and assigned numbers I to VII in decreasing length. A karyotype was constructed by means of the C-bands, mean chromosome lengths, and arm ratios. The C-banding procedure used in this study could be used to developed karyotypes for the other species of the genus Bromus and these C-banded karyotypes could be used to compare genomes within the genus

Morphological Characterization of Brachypodium distachyon (L.) P. Beauv. Natural Populations Collected from Different Geographical Regions of Turkey

Brachypodium distachyon (yalancı parlak brom), serin mevsim buğdaygilleri için yeni bir model bitkidir. Bu çalışmada, Namık Kemal Üniversitesi Ziraat Fakültesi Tarla Bitkileri Bölümü koleksiyonunda bulunan ve ülkemizin farklı coğrafik bölgelerinden toplanmış 48 adet doğal B. distachyon popülasyonu materyal olarak kullanılmıştır. Deneme tesadüf blokları deneme desenine göre 3 tekrarlamalı olarak kurulmuş ve kontrolsüz sera (plastik) koşullarında yürütülmüştür. Popülasyonlar 17 morfolojik özellik bakımından karakterize edilmiş ve morfolojik karakterlerin yükseklik ile olan ilişkileri incelenmiştir. Popülasyonların ortalama olarak bitki boylarının 24.7 cm, bayrak yaprak ayası boyunun 5.6 cm, bayrak yaprak ayası eninin 4.5 mm, biyokütlenin (kök hariç) 4.5 g bitki-1, başaklı sap sayısının 34 adet, başaksız sap sayısının 4 adet, bitki başına başakçık sayısının 111 adet, bitki başına tohum sayısının 372 tohum, bitkilerin sahip olduğu tohum ağırlığının 1.95 g, bin tane ağırlığının 5.22 g olduğu belirlenmiştir. Ayrıca, tohumların çimlenme süresinin ortalama 15 gün, bitkilerin başak çıkarma süresinin 125 gün ve çiçeklenme süresinin 136 gün olduğu tespit edilmiştir. Bitkilerin genel olarak yeşil renkte, tüylü yapıda ve dik formda olduğu, ancak bazı popülasyonlarda yatık ve yarı dik formların da bulunduğu gözlenmiştir. Morfolojik karakterlerdeki varyasyon Temel Bileşen Analizi (PCA) kullanılarak incelenmiştir. Yapılan korelasyon analizinde yükseklik arttıkça bitkilerde çimlenme süresinin azaldığı, bin tane ağırlığı ve bitki görünümü değerlerinin arttığı tespit edilmiştir. Çalışmadan elde edilen sonuçlara göre B. distachyon koleksiyonunda morfolojik karakterler bakımından büyük bir varyasyon olduğu saptanmıştır.Brachypodium distachyon is a new model plant species for cool season grasses. In this study, 48 natural B. distachyon populations from the collection stored at Namık Kemal University, Department of Field Crops; which were collected from different geographic regions of Turkey were used. Seventeen morphological characters and their relationship with altitude were investigated in the study. Based on the result of study, average properties were 24.7 cm for plant height, 5.6 cm for length of flag leaf, 4.5 mm for width of flag leaf, 4.5 g for biomass weigth (except the root), 34 for spike number per stem, 4 for number of stem without spike, 111 for number of spikelet per plant, 372 for number of seed per plant, 1.95 g for seed weight per plant, and 5.22 g for the thousand kernel weight. Additionally, average duration for seed germination, heading and anthesis were determined to be 15, 125, and 136 days respectively. It was determined that most of the plants had green colour, feathered structure and erect forms. But, semi-erect and even prostrate forms were also observed in some populations. All the data was subjected to principle component analysis. The results of the analysis indicate that B. distachyon collection used in this study have a tremendous morphological variation. Based on the results, duration of the germination had a negative correlation with increasing altitude while thousand kernel weight and plant appearance had a positive correlation

Bazı Buğdaygil Yem Bitkisi Türlerine Ait Populasyonların Çekirdek Dna Içeriklerinin Flow Sitometri Yöntemiyle Belirlenmesi Ve Ploidy Analizi Ile Tür Teşhisinde Kullanımı

Buğdaygil yem bitkisi türlerinin taksonomisi oldukça karmaşık olup türlerin teşhisi ve sınıflandırılması ciddi bir uzmanlık gerektirmektedir. Aynı cins içerisinde yer alan buğdaygil türlerinin birbirlerine çok benzemeleri, aralarında kolayca melezlenerek hibrit türler oluşturabilmeleri ve doğal varyasyon sebebiyle bu türlerin teşhislerinde ciddi sorunlar yaşanmaktadır. Buna ilave olarak buğdaygil yem bitkilerinde polyploidi olayıda çok yaygındır ve aynı türün dahi farklı kromozom sayılarına sahip formları mevcuttur. Bundan dolayı buğdaygil bitkilerine ait genetik kaynakların bilimsel araştırma ve ıslah çalışmalarında kullanılmadan önce tür teşhislerinin doğru bir şekilde yapılarak ploidi düzeylerinin belirlenmesi zorunludur. Bu çalışmanın amacı ıslah programlarında kullanmak amacıyla ülkemizin Doğu Anadolu Bölgesinden yeni toplanmış olan 215 buğdaygil yem bitkisi populasyonunun (Festuca sp, Phleum sp, Koeleria sp ve Agropyron sp) çekirdek DNA içeriklerini flow sitometri yöntemi ile ilk defa belirlemek ve elde edilen bilgiyi koleksiyonuı oluşturan türlerin teşhisi ve ploidi düzeyilerinin belirlenmesinde kullanmaktır. Çalışmadan elde edilen sonuçlara göre çalışma kapsamında karakterize edilen Koeleria, Festuca ve Phleum genetik kaynak kolleksiyonlarının birden fazla tür ve ploidy düzeyini içerdiği belirlenmiştir. Elde edilen bu sonuçlarda buğdaygil yem bitkisi genetik kaynaklarının ıslah programlarına dahil edilmeden önce muhakkak karakterize edilmelerinin gerekli olduğunu bu tür çalışmalar içinde flow sitometrinin şu an mevcut olan en hassas, hızlı, ucuz ve güvenilir metot olduğunu ortaya koymaktadır.Grass species included in the same genus are very similar to each other morphologically. They hybridize with each other in the nature easily and create hybrids. They also show natural variation. All of these make identification of the forage grasses and their taxonomy quite complicated. In addition to this, ploidy is also a common phenomenon in grasses and chromosome number varies even within the same species due to polyploidy. Therefore, it is necessary to identify species included in the forage grass germplasm collections and determine their ploidy correctly prior using them in research and breeding programmes. The objective of this study was to determine nuclear DNA content of 215 grass populations (Festuca sp, Phleum sp, Koeleria sp ve Agropyron sp) collected from natural flora of Eastern Turkey and use the the information in identification of the species and ploidy analysis. Based on the results of the nulear DNA content analysis done by using flow cytometer, Koeleria, Festuca ve Phleum collections investigated in this study included more than one species and ploidy levels. The results of this study proved one more time that grass genetic material collected from nature can have a mixture of different species and ploidy levels. Therefore, they need to be characterized before include them in research and breeding programmes and flow cytometer is the most accurate, cheap, and fast method for this type of studies

Genetic characterization of banana clones grown in Turkey based on nuclear DNA content and SRAP markers

This study was conducted to investigate the genetic relationships among banana clones grown in Turkey based on their nuclear DNA contents and SRAP markers. Four banana clones including 'Dwarf Cavendish', 'Grand Nain', 'Azman' and local 'Erdemli' were used as plant material. Nuclear DNA content of the banana cultivars estimated by flow cytometer and varied between 1.766 pg ('Erdemli') and 2.028 pg ('Grand Nain'). 'Azman' and 'Dwarf Cavendish' was similar nuclear DNA content. Genetic similarities of 4 banana clones were between 0.63-0.91 based on SRAP molecular marker. The local  'Erdemli' banana clone was the most distinct from the others. In conclusion, there is a high level of genetic variation among the banana clones grown in Turkey and the local clone 'Erdemli' is the most distinct one. This study showed that nuclear DNA content analysis together with molecular markers can be useful to assess the relationships among banana clones

DNA Content and Ploidy Determination of Bromegrass Germplasm Accessions by Flow Cytometry

Species of the genus Bromus represent ploidy states from diploid to decaploid. Ploidy determination of Bromus germplasm is necessary before it can be effectively used in breeding or genetic studies. The objective of this study was to characterize the ploidy of 322 accessions of four Bromus species [Bromus inermis Leyss, B. riparius Rehm, B. biebersteinii Roem and Schult., and B. inermis ssp. pumpellianus (Scribn) Wagnon] that are in the USDA National Plant Germplasm System (NPGS). Flow cytometry was used to determine DNA content of 10 plants of each accession. Mean DNA contents were correlated to ploidy level with root tip chromosome counts on selected accessions whose DNA content indicated that they represented different ploidy levels. On the basis of DNA content (pg [2C.sup.-1] = DNA content of a diploid somatic nucleus) and chromosome counts, mean DNA content and chromosome number was 22.62 pg [2C.sup.-1] for octaploid B. biebersteinii (2n = 8x = 56), 26.07 pg [2C.sup.-1] for decaploid B. biebersteinii (2n = 10x = 70), 11.74 pg [2C.sup.-1] for tetraploid B. inermis (2n = 4x = 28), 22.28 pg [2C.sup.-1] for octaploid B. inermis (2n = 8x = 56), 22.72 pg [2C.sup.-1] for octaploid B. inermis ssp. pumpellianus (2n = 8x = 56), 26.5 pg [2C.sup.-1] for decaploid B. inermis ssp. pumpellianus (2n = 10x = 70), 6.14 pg [2C.sup.-1] for diploid B. riparius (2n = 2x = 14), 22.15 pg [2C.sup.-1] for octaploid B. riparius (2n = 8x = 56), and 26.64 pg [2C.sup.-1] for decaploid B. riparius (2n = 10x = 70). Standard deviations of the mean values were 0.88 pg [2C.sup.-1] or less. Most B. inermis and B. inermis ssp. pumpellianus accessions were octaploid (93.75%), while the majority of the B. riparius and B. biebersteinii were decaploid (92.30%). The B. inermis and related species in the USDA NPGS were collected primarily from areas in the former USSR. The NPGS bromegrass germplasm could be enhanced by collections from western and central Europe, the Middle East, and China

DNA Content and Ploidy Determination of Bromegrass Germplasm Accessions by Flow Cytometry

Species of the genus Bromus represent ploidy states from diploid to decaploid. Ploidy determination of Bromus germplasm is necessary before it can be effectively used in breeding or genetic studies. The objective of this study was to characterize the ploidy of 322 accessions of four Bromus species [Bromus inermis Leyss, B. riparius Rehm, B. biebersteinii Roem and Schult., and B. inermis ssp. pumpellianus (Scribn) Wagnon] that are in the USDA National Plant Germplasm System (NPGS). Flow cytometry was used to determine DNA content of 10 plants of each accession. Mean DNA contents were correlated to ploidy level with root tip chromosome counts on selected accessions whose DNA content indicated that they represented different ploidy levels. On the basis of DNA content (pg [2C.sup.-1] = DNA content of a diploid somatic nucleus) and chromosome counts, mean DNA content and chromosome number was 22.62 pg [2C.sup.-1] for octaploid B. biebersteinii (2n = 8x = 56), 26.07 pg [2C.sup.-1] for decaploid B. biebersteinii (2n = 10x = 70), 11.74 pg [2C.sup.-1] for tetraploid B. inermis (2n = 4x = 28), 22.28 pg [2C.sup.-1] for octaploid B. inermis (2n = 8x = 56), 22.72 pg [2C.sup.-1] for octaploid B. inermis ssp. pumpellianus (2n = 8x = 56), 26.5 pg [2C.sup.-1] for decaploid B. inermis ssp. pumpellianus (2n = 10x = 70), 6.14 pg [2C.sup.-1] for diploid B. riparius (2n = 2x = 14), 22.15 pg [2C.sup.-1] for octaploid B. riparius (2n = 8x = 56), and 26.64 pg [2C.sup.-1] for decaploid B. riparius (2n = 10x = 70). Standard deviations of the mean values were 0.88 pg [2C.sup.-1] or less. Most B. inermis and B. inermis ssp. pumpellianus accessions were octaploid (93.75%), while the majority of the B. riparius and B. biebersteinii were decaploid (92.30%). The B. inermis and related species in the USDA NPGS were collected primarily from areas in the former USSR. The NPGS bromegrass germplasm could be enhanced by collections from western and central Europe, the Middle East, and China