With an annual global production of approximately 25 million tons, the common bean (Phaseolus vulgaris L), a member of the genus Phaseolus, is one of the major protein sources used as food for humans. In this study, it was aimed to investigate the genome size of the common bean genetic resource collection (154 common bean accessions) in Turkey by flow cytometry (FCM) and determine whether geographical variables affected the genome size. In addition, the number and distribution of 5S and 45S ribosomal DNA loci were designated by performing a fluorescence in situ hybridization (FISH) analysis in some of the accessions. The FCM analyses revealed that the mean nuclear DNA content of the accessions varied from 1.28 pg2C-1 to 1.55 pg2C-1 (mean 1.35 pg2C-1), and the differences between these accessions were statistically significant (P < 0.01). Intraspecific variation in the genome size was determined, and a positive correlation was found between the altitude and genome size. However, latitude and longitude did not have any statistically significant effect on the genome size. In the principal coordinate analysis, the accessions were divided into 3groups. Based on the results of the FISH analysis performed on 5 different accessions with varying genome sizes, using 5S and 45S rDNA genes as probes, the number of 5S rDNA loci was 4 in the common bean and stable among the common bean accessions, while the number of 45S rDNA loci was highly polymorphic, varying between 6 and 16. Consequently, it was determined in the present study that the genetic resource collection of common bean had a wide variation in terms of genome size and genome organization.

Hypericum perforatum L. (St John's Wort) is a medicinal plant that produces pharmaceutically important compounds with antidepressive and anticancer activities. H. perforatum is a facultative apomictic species as it has the ability to reproduce with multiple reproduction mechanisms affecting genetic structure and chemical composition of the plants. The objective of this study was to determine nuclear DNA contents and ploidy levels of H. perforatum L. plants growing naturally in the flora of Turkey. The seeds of 39 Hypericum perforatum L. accessions collected from 23 different locations in Turkey were used in the study. Nuclear DNA contents of three different seedlings for each of the 39 H. perforatum accessions were determined using flow cytometry. Based on the results of flow cytometric analysis, nuclear DNA contents of the accessions varied between 0.8-2.57 pg 2C-1. Nuclear DNA content differences observed among H. perforatum accessions were statistically significant (P<0.01) and the Duncan test revealed that the accessions formed three clearly distinguishable main groups. Mean nuclear DNA contents of each group were 0.80 pg 2C-1 , 1.58 pg 2C-1 (1.36-1.73 pg 2C-1) and 2.38 pg 2C-1 (2.15-2.57 pg 2C-1). Ploidy levels were determined by correlating nuclear DNA content of accessions with the number of their mitotic chromosomes by counting chromosome number of one plant from each group. Findings suggest that H. perforatum accessions used in this study had the following three different ploidy levels: diploid, tetraploid and hexaploid. The percentages of diploid, tetraploid and hexaploid accessions were 2.2, 86.4 and 11.4% respectively.

The evolution of chromosome number and ribosomal DNA (rDNA) loci number and localisation were studied in Onobrychis Mill. Diploid and tetraploid species, as well as two basic chromosome numbers, x = 7 and x = 8, were observed among analysed taxa. The chromosomal distribution of rDNA loci was presented here for the first time using fluorescence in situ hybridisation (FISH) with 5S and 35S rDNA probes. Onobrychis species showed a high polymorphism in the number and localisation of rDNA loci among diploids, whereas the rDNA loci pattern was very similar in polyploids. Phylogenetic relationships among the species, inferred from nrITS sequences, were used as a framework to reconstruct the patterns of basic chromosome number and rDNA loci evolution. Analysis of the evolution of the basic chromosome numbers allowed the inference of x = 8 as the ancestral number and the descending dysploidy and polyploidisation as the major mechanisms of the chromosome number evolution. Analyses of chromosomal patterns of rRNA gene loci in a phylogenetic context resulted in the reconstruction of one locus of 5S rDNA and one locus of 35S rDNA in the interstitial chromosomal position as the ancestral state in this genus.

Silene bolanthoides Quézel, Contandr. & Pamukç. is an endemic species from Kazdagi (Mt. Ida), Canakkale-Balikesir, Turkey. In order to develop an efficient shoot regeneration protocol, the leaf, nodal and internodal explants of S. bolanthoides were cultured on Murashige and Skoog (MS) medium containing benzyladenine (BA) alone or in combination with α-naphthaleneacetic acid (NAA). The highest number of regenerated shoots (5.75±0.1) was obtained from nodal explants that were cultured on MS medium with 8.8 µM BA+0.54 µM NAA. Regenerated shoots were rooted on MS medium without plant growth regulators (PGRs). Rooted plants (2-3 cm) were separately transferred to pots containing a mixture of peat and perlite (3:1 v/v) and acclimatized successfully in a growth chamber. Genetic stability of the propagated plants was assessed by flow cytometry and cytological analysis. Flow cytometry analysis demonstrated that regenerated plants had 2.61±0.01 pg nuclear DNA (2C) and seed-derived plants had on average 2.58±0.02 pg/2C. Cytological analysis showed that the regenerated plants had the same chromosome number as seed-derived plants of S. bolanthoides (2n=24). It was determined that regenerated plants were uniform in chromosome number and had a similar DNA content to the seed-derived ones, indicating that the described efficient shoot regeneration protocol can be applied for ex situ conservation of this species.