Identification and virules of Sphaeropsis tip blight (Sphaeropsis sapinea) on Pinus spp. in Istanbul and Bursa parks

Abstract

Sphaeropsis sapinea tip blight is one of the most destructive fungal diseases of pine trees in the world. It causes shoot blight, canker, collar rot, root disease and blue stain of Pinus spp. As a result of surveys performed in the parks, recreation areas and groves in Istanbul and Bursa provinces in January, June and October 2015, it was observed that the agent especially causes disease on Pinus spp. The disease was observed as dead, brown needles at the tips of branches, shoot blight and cankers on pine stems and branches. Twenty eight diseased pine samples were collected from parks, recreation areas and groves. Totally 15 Sphaeropsis sapinea isolates were obtained. Cultural and morphological characteristics of the isolates were determined using cultures grown on potato dextrose agar (PDA). Cultures on PDA were initially white with profuse aerial mycelia that after one week turned grey to blackish. Identification of the pathogen was based on morphological characteristics of the conidia and DNA sequence analysis. Genomic DNA was extracted and the internal transcribed spacer (ITS) region of the rDNA was amplified using primers ITS1 and ITS 4. Pathogenicity tests were made with twig inoculation method. All isolates formed lesions on twigs.