Botrytis cinerea as causal agent of sunflower seed grey mould

Abstract

Sunflower (Helianthus annuus L.) is one of the most important oil crops worldwide, including Serbia, where it is grown on about 200,000 ha with an average yield of 3 t/ha. Botrytis cinerea Pers. (1794) regularly occurs on sunflower seeds associated with the phenology of the host plant. However, sunflower seed is often affected by the Rhizopus spp., which causes similar symptoms on seed and seedlings as B. cinerea, and it is important to reliably differentiate those species based on morphological and molecular characteristics. The method used in this study for the detection of B. cinerea is described by ISTA method 7-003. The main task of this study was to isolate the causal agent of grey mould and rot of sunflower seed and seedlings. Infected seeds were covered with overgrown dark-grey mycelia with sporulation. In order to isolate the pathogen, the infected seed was transferred onto potato dextrose agar (PDA) and incubated for 7 days at 20°C. For morphological identification, 11 isolates were single-spored and subcultured onto PDA. Strains formed straight, noddy conidiophores, branched at the top and resembling a cluster with conidia. Conidia were ovoid or elliptical avg. 11.6 × 7.5 µm in size.