Ethrel

Pistacia atlantica Desf.is one of the main wild species of Pistacia in Iran and one of its products is an oleo-gum-resin briefly called Saqez gum. The effect of Ethrel injection (EI) on Saqez gum production was studied during summer 2018 at three habitats (Kuh-e Birk, Goharkuh and Mirabad) inSistan and Baluchestan province, Iran. Four treatments, 0 (distilled water), 10, 20 and 30% concentration of Ethrel, were administered by injection into the tree trunk. The investigation was carried out in a randomized complete block design and 36 trees were injected. Saqez gum essential oil (EO) was extracted by Clevenger apparatus and identification and quantification of EO components were performed by GC-MS and GC-FID, respectively. The results showed that applying the EI treatment increased the gum yield of trees by an average of 4.4 times. The highest gum yield (29.33 g/tree) was obtained with EI at 10% in the Kuh-e Birk habitat, while the lowest yield (3.33 g/tree) was observed in the control treatment of the Mirabad habitat. In total, 39 compounds were identified in the EOs and α–pinene was found to be the predominant compound in all samples (66 to 91.8%). Other compounds such as β–pinene, camphene, sabinene, cis-limonene oxide, neo-iso-verbanol, ρ–cymene and ρ–cymenene were identified in the EOs. EI treatments did not have a significant effect on EO components and the amount of α–pinene and β–pinene in EI 30% treatment increased slightly. Due to the desired quantity and quality of gum in the EI 10%, this method of exploitation can replace the traditional method.