Isolation and identification of grapevine trunk diseases in Palestine and possible use of bacteria as biocontrol agents against the disease

Abstract

The grapevine trunk disease (GTD) has been considered a real threat on grape production. This study aimed to identify the GTD causing agents in Palestinian grapevine orchards and to evaluate the efficacy of bacteria to control the disease under in vitro conditions. Two fungal isolates; Fusarium solani isolate GR and Neofusicoccum parvum isolate GR3 were identified and diagnosed using PCR and BLASTn analysis.  After that, five bacterial isolates were tested for their efficacy against the growth of the fungi.  Pseudomonas fluorescence isolate ORS3 and Pseudomonas fluorescence isolate PFL showed very strong inhibition zones (> 10 mm, ++++) against both fungi under in vitro conditions.  The other bacterial isolates were able to inhibit the fungi but the inhibition was less and varied among the bacteria. The effect of the bacteria on F. solani isolate GR was greater than that on N. parvum isolate GR3. Up to our knowledge, this study was the first of its kind in Palestine that identifies GTD. Further studies are needed to test the efficacy of the bacterial isolates under field conditions.