Study of the rootstock and cultivar effect in PAL activity, production of phenolic and flavonoid compounds on flower, leaf and fruit in Pistachio (Pistacia vera L.)

This study was carried out to assess and compare three pistachio cultivars (Ahmadaghaii, Ohadi and Kallehghuchi) on two rootstock (Mutica, Ahli) in relation to PAL activity, phenolic, flavonoid and anthocyanin in leaves, flowers, fruits and selection of the most suitable and compatible rootstock and scion in order to obtain resistance to environmental stresses. The results showed increased PAL activity, total phenolic and flavonids and also positive correlation was observed between PAL activity and the existing compounds on leaves and flowers in Mutica-Ahmadaghaii, that showed a better resistence this than the others in environmental stresses. PAL activity and total phenolic in fruits of pistachio suffered a decreased when the maturation processes began. The hulls of the pistachio fruits, contained high level of phenolic compounds, (especially in Mutica-Ahmadaghaii) which may function as a protective layer and protective chemical against ultraviolet radiation and pathogen. The final concentration of phenolic compounds and flavonoids and antocyanins in the kernel, depended on the PAL activity in kernel’s cultivar. Our results indicated the presence of a number of bioactive compounds in kernel and the highest amount belonged to Mutica-Ahmadaghai. The results of this study showed that rootstock may affect the antioxidant compound in kernel in pistachio tree.