Infection and Colonization of Turf-type Bermudagrass by Ophiosphaerella Herpotricha Expressing Green (Gfp) or Red (Tdtom) Fluorescent Proteins

Abstract

Turf-type bermudagrasses were used to study infection and colonization by isolates of O. herpotricha expressing green (GFP) and red (tdTom) fluorescent proteins. The presence and location of O. herpotricha and necrosis were observed using epi-fluorescence microscopy. Overall, C. transvaalensis colonization by O. herpotricha was less dense, less aggregated, and less necrotic than Tifway and Midlawn. Tifway was more susceptible in terms of visible macroscopic root surface necrosis and extent of epidermal colonization. Numerous stroma or aggregates of hyphae were observed on Tifway and Midlawn root surfaces. Stele colonization was observed in C. transvaalensis roots but not in Tifway and Midlawn. Visible necrotic lesions were also observed on Tifway and Midlawn stolons. Mat-like structures were also observed at the point of attachment. No cortical colonization was observed on Tifway, Midlawn, and the C. transvaalensis at 28 days post-inoculation when stolons were inoculated at internodes without wound