Biocontrol potential of Acremonium sclerotigenum (Moreau & R. Moreau ex Valenta) W. Gams against wheat and oat rust fungi (Puccinia species)

Mycoparasitic isolates colonizing Puccinia graminis.f.sp. tritici of wheat under field conditions was isolated and purified. Morphological studies established the identity of the isolates as Acremonium sclerotigenum (Moreau & R. Moreau ex Valenta) W. Gams. In screening for the in vitro mycoparasitic activity, by blending the conidial suspension of the mycoparasitic isolate, SHZA1, with the uredospores of the respective rust pathogens, a significant reduction in germination of uredospores and germ tube elongation of cereal rust pathogens viz., stem rust (Puccinia graminis.f.sp. tritici), leaf rust (Puccinia triticina) of wheat, stem rust (P. graminis f.sp. avenae), and crown rust (P. coronata f.sp. avenae) of oats were observed. The culture filtrate of the mycoparasite also inhibited the uredospore germination of the rust fungi and was more effective than the spore suspension. Under glasshouse conditions, spraying of the culture filtrate of SHZA1 suppressed the development of uredosori of rusts. Given potential mycoparasitism, the identity of the isolate was validated by sequencing the ITS region of rDNA.