ISOLATION AND IDENTIFICATION OF THE CAUSAL AGENTS OF ROOT AND CROWN ROT OF PISTACHIO TREES IN THE SISTAN AND BALUCHISTAN PROVINCES

Pistachio is the most important commercial product in Iran and root and crown rot (gummosis) is the most serious diseases of this crop.
Causal agents of the disease were unknown in Sistan and Baluchistan province where 5000 ha are under cultivation of pistachio.
During 2002-2003, thirty pistachio orchards including pistachio trees of different ages were inspected throughout different seasons.
Eighteen Phytophthora isolates were isolated using citrus leaves pieces as baits on water-saturated soils collected from around the infected trees and cultured on PARPH medium.
Some isolates were isolated culturing the surface disinfected tissues of root and crown of infected trees directly on PARPH as the semi-selective medium too.
Two groups of isolates were obtained.
Based on the morphological and physiological characteristics of the Sistan and Bluchistan pistachio isolates, the first group of isolates was identified as Phytophthora pistaciae sp. nov.
Mirabolfathy and the second group identified as Phytophthora nocotianae Bred de Haan.
The two Phytophthora species were found pathogens using unripe pear and apple fruit inoculation method, detached pistachio twigs inoculation method and inoculated vermiculite method to infect the pistachio scions through the root area and artificial inoculation of the crown area with a plug of cultured isolate medium.
This is the first report of incidence of pistachio tree gummosis and its causal agents from Sistan and Baluchistan province.

IV International Symposium on Pistachios and Almonds

S.R. Fani, H.R. Zamanizadeh, M. Mirabolfathy

isolation, identification, gummosis, root and crown rot, Phythophthora, pistacia sp.nov., P. nicotianae

https://doi.org/10.17660/ActaHortic.2006.726.111