Morphological and Molecular Identification and PCR Amplification to Determine the Toxigenic Potential of Fusarium graminearum Species Complex (FGSC) Isolated from Wild Grasses in Iran

Abstract

In order to explo re biodiversity of Fusarium species associated with the inflorescences of gramineus weeds, heads and inflorescences were collected from wild grasses in west of Iran. Sixty samples, mostly from infected spikes were collected from different sites of western Iran. Nine species from 9 tribes of the Poaceae family were identified based on pollen morphology using light microscopy and scanning electron microscope. Sixty Fusarium isolates were obtained from diseased spikes and identified into five species F. gramin earum (40%), F. asiaticum (20%), F. acuminatum (20%), F. equiseti (10%), and F. proliferatum (10%). The identification of the members of F. Graminearum Species Complex (FGSC) was confirmed molecularly using Fg16F/Fg16R primers. F. asiaticum isolates were d istinguished from other FGSC using Fg6CTPSf177/Fg16R primers. The phylogenetic trees based on Translation Elongation Factor - 1 α (TEF - 1α) dataset clearly separated all morphological taxa. PCR - based detection of mycotoxin - synthesis - pathway gene was also used to determine the potential to produce trichothecenes (DON and NIV) . Among 60 tested isolates, 16 isolates (27%) be long ed to DON chemotype and 10 isolates (17%) were NIV chemotype. These results show that DON was the most common chemotype in western Iran. T o our knowledge, this is the first report on molecular identification of Fusarium species isolated from poaceous wild grasses in Iran. Keywords: Fusarium spp. , Iran , Poaceous wild grasses , TEF - 1α , Trichothecenes.