Study on the inhibition of Trichoderma sp.against Fusarium oxysporum f.sp.cubense in banana

A fungal strain,designated as G2,with remarkable ability of effective antagonist against Fusarium oxysporum f.sp.cubens,was isolated and identified as Trichoderma sp.based upon 18S rDNA gene analysis.With solid and liquid cul-tures,the inhibitive efficacy to the growth of Fusarium oxysporum f.sp.cubens was primarily studied.The experimental re-sults showed that the cells of Fusarium oxysporum f.sp.cubens were completely covered by short fiber-like hyphace and spore stem of G2 within 7 days in the dual culture plate,and in the antagonist plate,the average rate of inhibitory by the cul-ture solution of G2 was about 90.4%,the average rate of the inhibitory by volatile substance reached 68.3%.After 10 days' incubation with 20%(v/v) fungal strain G2,the melt of the pathogenic mycel and spore were observed in the liquid culture containing 1.0×107 cfu·L-1 Fusarium oxysporum f.sp.cubens,suggesting that the strain G2 can strongly inhibit the growth of Fusarium oxysporum f.sp.cubens.