Plant Growth Promotion of Trichoderma virens, Tv911 on Some Vegetables and Its Antagonistic Effect on Fusarium Wilt of Tomato

Abstract

Application of synthetic agro-chemicals for plant growth enhancement and weeds, pest and disease control would cause negative impacts on biodiversity, environment and human health (Debenest et al., 2010; Geiger et al., 2010). Accordingly, organic agriculture has become popular with rising trend throughout the world (Willer et al., 2009). Nowadays, many microbial products are available for pest and disease management in crop production (Berg, 2009), and also available for plant growth promotion as a biofertilizer (Rodríguez and Fraga, 1999; Vessey, 2003). The genus Trichoderma (Teleomorph Hypocrea) has attracted an increasing attention and interest because of their economic value, and it is widely used not only as a biocontrol agent especially for soil borne plant pathogenic fungi (Qualhato et al., 2013) but also for enzyme production in industrial usage (Ahamed and Vermette, 2008). Additionally, it has the potential to degrade environmental hazardous chemical residue from the contaminated agricultural soil (Arfarita et al., 2013). Antagonist mechanisms of Trichoderma spp. are competition for nutrient and space, and direct mycoparasitism with antibiosis such as cell wall degrading enzymes to inhibit the growth of plant pathogens (Benítez et al., 2004). Moreover, these species are common and persistent fungi in the rhizosphere soil microbial community in a natural ecosystem (Lidia et al., 2011). Among them, T. harzianum, T. virens, T. asperellum, T. koningii and T. hamatum were colonizing to the roots and rhizosphere and some strains of each species have been identified as a plant growth promoter of the early growth stage of bean plants (Hoyos-Carvajal et al., 2009). Isolates of T. harzianum increased plant height and leaf area of pepper and cucumber seedlings and reduced damping-off disease significantly under commercial growing conditions (Inbar et al., 1994). Isolates of T. virens produced plant growth regulator, the auxin-related compounds, and enhanced biomass and root growth of Arabidopsis (Arabidopsis thaliana) seedlings (ContrerasCornejo et al., 2009). The morphological and cultural properties of T. harzianum and T. vriens were not obviously different (Sharma and Singh, 2014), and it can be accurately identified by molecular sequencing of ITS gene (White et al., 1990). In our previous study, several Trichoderma species isolated from waste paper sludge compost abandoned by paper manufacturing company in Saga, Japan during 2014― 2016 were characterized by their paper degradation ability. As the results, these isolates are potentially responsible for production of cellulose degrading enzyme (cellulase) and total crude protein in treated paper wastes (Peng et al., 2016). Remarkably, there is no report concerned to the characterization of Trichoderma spp. derived from such paper sludge compost and possibility of usage of these isolates as a biological resource of plant growth promotion and antagonist of the plant pathogenic fungi. Although, cel-