Leaf blight caused by Didymella glomerata on blackberry in Turkey

Abstract

The cultivation of blackberries has recently increased in Turkey, despite the fact that wild blackberry types have grown almost everywhere in the country. During the summer of 2011, leaf blight symptoms were observed in a blackberry vineyard in Karlısu, as well as on wild blackberry plants in Altınözü, Hatay province, Turkey. Based on morphology, fungal isolates obtained from these blighted leaf margins shared similar morphological characteristics and were tentatively identified as Didymella glomerata. To confirm the morphologic identification, the nucleotide sequences of a representative isolate’s ITS, LSU, and tub2 regions of DNA were used. The sequences of three regions were 99–100% identical to D. glomerata isolate sequences in GenBank. Healthy blackberry suckers of the thornless blackberry cultivars ‘Triple Crown’ and ‘Chester’ grown in pots were inoculated with spore suspension on foliar parts under greenhouse conditions for pathogenicity testing. D. glomerata was extremely virulent, causing severe leaf blight in both blackberry cultivars. D. glomerata was constantly isolated from inoculated plants’ leaf lesions. This is the first report of D. glomerata infection of blackberry, a novel host for this pathogen in Turkey and around the world. More research into the biology and management of the disease is required.