Determination and assesment of the sex chromosomes of male trees of pistachio (Pistacia vera L.) using in vitro culture

The chromosome number and karyotype analysis of male trees of Pistacia vera L. was investigated to determine the sex chromosomes. For karyological determination, root tips were obtained from in vitro derived shoots. Afterwards fifty plates of mitosis were used for the karyotyping, the five best metaphase plates were measured for karyotype analysis, karyogram and idiogram. The conclusions obtained from the chromosome studies illustrated that the chromosome complement of P.vera L. has 2n = 30 chromosome pairs with metacentric, submetacentric, subtelocentric and telocentric centromeres. Karyotype analysis revealed that male trees of P.vera L. have heteromorphic sex chromosomes (Xy). The largest pair of chromosomes have different physical features from the other pairs. Neither polyploidy nor satellite was detected on any of these chromosome plates.