Detection and identification of some fungal agents causing grapevine decline in Northern Khorasan Province vineyards using PCR technique

One of the most significant and destructive grapevine diseases is Esca which is caused by several fungal species. Trunk disease causes stunted growth، reduced yield، and ultimately، vine death. For this reason، during the summer 2011، infected samples were collected from Bojnourd (North Khorasan province) vineyards. Infected trunk samples were acquired that they were showing white and brown rots، dark brown spots and also samples without apparent symptoms. The aims of this work were، firstly، to apply species –specific primers for detecting fungal agents associated with Esca disease of grapevine; and comparing this method to the classical ones، and secondly، to detect frequency of each pathogenic agent using molecular and classical methods. In molecular method، species-specific primers which designed based on ITs region of rDNA were used to detect fungal agents of the Esca disease. They yielded a single amplicon of 550 bp، 360bp and 415 bp for F. mediterranea، Pa. chlamydospora and Phaeoacremonium spp. respectively. Results showed that the maximum frequency of incidence was related to P. chamydospora and Phaeoacremonium spp was in second. The lowest incidence frequency rate was related to F. mediterranea which was observed only in sample with white rot symptoms. Primers defined here can be used in the nursery sanitation program to produce plant free of Esca disease.