Morphological, cytological and molecular evaluation of wild Persian roses of Iran‎

Since the ploidy level and nuclear DNA amounts are less exposed to environmental conditions and natural selection than most morphological traits, and are more stable in the stages of evolution, they are used to study variation among different species. Knowledge of the genome size may help in studying the phylogenetic relationships, correlation of the physiological and agronomical characters to the genome size, determination of the genetic fingerprinting approaches in investigating the population structure, gene flow, and so on. In order to study the diversity of Iranian Rosa spp., cytogenetic and flow cytometry (FCM) analyses were carried out on 14 rose species present in Iran. Plants were collected from different parts of the country, for each plant, root tips and young leaves were used in the investigations. For numerical karyotype analysis, chromosome characteristics such as total length of the chromosome ( M), length of long arm ( M), length of short arm ( M), arm ratio and centromer index were measured and chromosome types were determined. Chromosome number and ploidy level of the investigated species ranged from diploid (2n = 2x = 14) to hexaploid (2n = 6x = 42) and the chromosomes of all species were either metacentric or sub-metacertric. FCM analyses were conducted using 4', 6-diamidino-2-phenylindole (DAPI) and propidium iodide (PI). The mean 2C-value of different species showed a varying degree from 0.83 pg in R. persica to a four-fold higher amount of 3.54 pg in R. pulverulenta. UPGMA phenogram describing the similarities between rose species according to their karyotype characteristics was drawn and four clusters showing the simlarity level of 60% were determined. Distribution of the species according to the first and second component values confirmed the results of cluster analysis. Comparing these two revealed that grouping of the species was strongly affected by the second component. Since the main part of the second component was coefficient of variation, most of the species with similar coefficient of variation were placed in one group. Present research provided the information about karyotyping and DNA amounts of Iraninan rose species for the first timeThe results from karotyping characteristics showed very little diversity between the species. However, the data on genome size and polidy level showed great diversity between the species which could be used in further breeding and research programs. Keywords: chromosome number, flow cytometry, karyotyping, nuclear DNA amount, ploidy level, rose species