Studies on the transmission of some Fusarium spp. to potato progeny tubers from mother plants and its biological control

Fusarium spp. attack potato roots causing root-rot, damping-off and wilt disease in Assuit Governorate. Forty-five Fusarium isolates were isolated from F. nygamai, F. acutatum, F. solani, F. proliferatum, F. subglutinans, and F. oxysporum. Isolates were tested for their pathogenic capability on Burn potato variety during growing season 2007/2008. Isolates infect potato plants causing either damping-off or wilt symptoms. Isolates varied in their virulence. Role of potato tuber seed in the transmission of the causal pathogen to daughter using Electrophoresis. Protein profiles of the tested isolates divided into four sub-clusters at similarity levels 93.79, 91.55 and 92.62% while isolate of Fusarium profile No. 11 formed separate sub-clusters at similarity level 69.79%. F. nygamai and F. solani were notable exception because profile No. 4 of F. nygamai from roots and profile No. 4 from sprouts were almost identical (similarity level 96.81%); similarity level between profile No. 8 from roots and profile no/8 from sprouts was 95.44%. Results prove that F. nygamai and F. solani are potato tuber seed-borne fungus. T. harzianum, T. viride, T. longibrachiatum, G. virens and E. nigrum or its filtrate inhibited the growth of F. nygamai, F. acutatum, F. solani, F. proliferatum, F. subglutinans and F. oxysporum. The formulation of T. harzianum, T. longibrachiatum and G. virens against tested pathogenic fungi reduce disease incidence under greenhouse conditions.