Biological control of Fusarium wilt of chickpea using isolates of Trichoderma atroviride, T. harzianum and T. longibrachiatum.

摘要

The efficiency of the antagonist species Trichoderma atroviride (strains Ta.3, Ta.7 and Ta.13), T. harzianum (Th.6, Th.12, Th.15, Th.16 and Th.18) and T. longibrachiatum (TL.1, TL.2, TL.4, TL.5, TL.8, TL.9, TL.10, TL.11, TL.14 and TL17) against Fusarium wilt (caused by Fusarium oxysporum f.sp. ciceris) was compared using in vitro- and in vivo-based bioassay. A significant decrease of both growth and conidia production of the pathogen was obtained compared to the control. The highest percentages of diameter colony reduction and conidial production were obtained with Ta.13, causing 65.64% reduction in colony diameter (direct confrontation), 48.71% reduction in colony diameter (indirect confrontation), and a complete inhibition of conidial production. Once more in direct confrontation, T. atroviride overgrowth the pathogen colony and sporulate above. The seed treatment by Trichoderma spp. isolates before sowing in a soil already infested by the pathogen led to a significant decrease of disease severity compared to the untreated control. The weakest index of disease severity was obtained with Ta.13, which caused 83.92% reduction compared to the control. The most effective isolates in protecting chickpea seedlings against the disease were Ta.3, Ta.7 and Ta.13 as well as Th.16. The reduction of disease severity was associated with an increase of the vegetal growth including the stem height as well as the plant fresh and dry weights.