Native Rhizospheric Microbes Mediated Management of Biotic Stress and Growth Promotion of Tomato

Abstract

The incidence of biotic perturbation in plants has been amplified due to increased resistance and the resurgence of pathogens. To mitigate stress and promote food production, agrochemicals are being used boundlessly and they have augmented the problem of disease re-occurrence and agroecosystem degradation. With the perception of urgency to reduce biotic stress sustainably, the present study was undertaken. Four native rhizospheric microbes: Trichoderma lixii, T. brevicompactum and two strains of Bacillus subtilis, were evaluated for their antagonistic potential toward soil-borne and foliar pathogens of tomato under pot conditions. The data obtained revealed T. lixii as the most effective isolate, which substantially reduced the disease severity and promoted plant growth. In two consecutive pot experiments, T. lixii was observed to reduce the fusarium wilt and early blight severity by 32% and 31%; and 30% and 25%, respectively, compared to the untreated control. Moreover, T. lixii was reported to colonize the plant roots, which was evident from the result obtained for biofilm formation and spores colonization on root cells. TvR1 also improved the photosynthetic content of both infected and non-infected plants. The conclusion drawn from the result suggested that the native microbial rhizospheric isolate T. lixii was effective in ameliorating the biotic stress, which might be due to root colonizing ability, and therefore, it could be designed into a bioinoculant for green agriculture.