Investigation of potential differences in the sex of siirt pistachio (Pistacia vera L. cv. Siirt) trees and saplings using morphological and physiological techniques

Sex identification in Pistacia species is economically important for pistachio producers because their long juvenile period delays crop production and gains. Since there is no easy method to identify sex during the juvenile period of this plant, morphological and physiological methods are expected to help in sex identification at the juvenile stage of Pistacia vera L. cv. Siirt (siirt pistachio) to determine potential differences in the sex of siirt pistachio trees and saplings. In the present study, the physiological and morphological differences were compared between female and male trees. Sixteen saplings were grown in the same field and environmental conditions. We measured GSH, GSSG, GR enzyme activity, total soluble sugar and protein, proline, MDA, chlorophyll-a, chlorophyll-b, carotenoid, pH values, and stomatal density of the leaf samples randomly selectedfrom the sixteen saplings, and five male and five female trees. While the average GSH, GSSG, and GR activity of male trees was 2.45, 0.66, and 9.72, respectively, it was 5.94, 1.54, and 5.53 in female trees. The stomatal density of female and male trees and saplings was determined as 8.33-12.33, 15.00-23.66, and 9.66-24.00, respectively. The pH value was measured between 4.83-5.40, 4.64-4.74, and 4.23-4.76, respectively, in female and male trees and saplings. According to the pH values, the acidity of saplings was higher than in male trees, whereas it was higher in male trees than in female trees. However, proline, malondialdehyde (MDA), total soluble sugar and protein, photosynthetic pigments, and carotenoid did not display any significant differences between female and male trees and saplings. Considering the results of GSH, GSSG, and GR enzyme activity and stomatal density, which differed significantly between trees and saplings, S7 showed similarity to female trees, whereas S13 showed similarity to male trees