Karyotypic analysis of Quercus infectoria G.Oliver

Quercus infectoria G. Oliver is one of the valuable and main species of Zagros forests of Iran. The species is important in environmental, economic, genetic and medicinal aspects. Cytogenetic studies on plant species and their populations provide quantitative information on evolution history and determine relationships between the species and karyological characteristics. Our study aimed to determine karyotypic and chromosomal constitution of Quercus infectoria and its karyological diversity among four populations of the species in western Iran (Sardasht, Marivan, Shine-Ghalaei and Kakasharaf) using root meristem and visual analyses. After pretreatment, stabilization, hydrolysis and staining, microscopic stages were performed and karyotypic parameters were investigated. Results showed that chromosome number of most the observed cells were 2n =2x= 24 but 2n=2x=25 and 2n=2x=26 and triploidy were also observed in several cells. Analysis of variance and mean comparisons were performed on 3 to 10 cells of 3 to 7 genotype of each population. Results showed significant differences among the studied populations in properties such as chromosome length, long and short arm length. Symmetric karyotype indices are indicative of the relative asymmetry of chromosomes in the studied populations. Principal components analysis based on karyotypic parameters showed that chromosome length, long arm length and short arm length, played the most important role in the first component. The first component contained more than 75% of total karyotypic variation. Cluster analysis classified the populations into two classes. Shine-Ghalaei and Kakasharaf was assigned to one cluster and Marivan and Sardasht, allocated to the second one.