Antagonistic Effects of Different Soil Isolate Bio-agents against Fusarium oxysporum f. sp. Cubense TR4 In vitro and Molecular Characterizations

Bananas are the earliest fruit crop cultivated by humans from ancient times in India and have great social-economic importance, merged with the country's cultural heritage. Different bio-agents were isolated from the rhizosphere of wilt affected banana plants cultivar Grand naine on Fusarium oxysporum f. sp. cubense TR4 areas of Bihar. All isolated bio-agents were tested against FOC TR4 in vitro condition by dual culture technique. The maximum inhibition over control at 10 days of inoculation was recorded in Trichoderma asperellum 1(Tr1) (64.82%), followed by Trichoderma asperellum 2(Tr2) (62.70%), Aspergillus flavus (35.00%) and minimum in Penicillium chrysogenum (22.62%). The result clearly showed that in vitro Trichoderma asperellum 1 was highly effective while Penicillium chrysogenum was found least effective antagonistic against Fusarium oxysporum f. sp. cubense TR4 in vitro. Molecular characterizations of two morphologically different Trichoderma spp. were identified as two different strains of Trichoderma asperellum 1 and Trichoderma asperellum 2.