screening of endophytes for the control of root rot pathogens of pepper (Capsicum annum)

Gurung, Sunil. Screening of endophytes for the control of root rot pathogens of pepper (Capsicum annum). Major diseases impact pepper production including root rot significantly damages plants. Pepper production requires routine fungicide application which increases the cost of production. In addition, chemicals exposure is toxic to human, animal, environment, and also destroys natural microflora consisting beneficial microbes. As an effort to reduce the use of chemical fungicides, the objective of this study is to identify potential biological agents against root rot pathogens of pepper. Dogwood endophytes were screened for the bioactivity against root rot pathogens (Phytophthora capsici, Fusarium solani, Fusarium oxysporum and Macrophomina phaseolina). Fungal endophyte A22F1, identified as Nigrospora sphaerica showed antagonism against fungal pathogens in invitro condition. Since no other fungal pathogens showed any virulence in invitro experiment except Phytophthora capsici isolate Lt6745, this isolate was used in the greenhouse experiment. Three cultivars California Wonder, Pepper Cayenne and Numex primarvera were used. Experimental units of all the cultivars treated with Nigrospora sphaerica (prior or later inoculated with Phytophthora capsici ) had significantly lower root rot disease severity compared to the plants only inoculated with Phytophthora capsici. While the plants inoculated only with Nigrospora sphaerica were asymptotic. In addition, Nigrospoara sphaerica effectively colonized pepper root and leaf but no significant effect was found in the growth parameters like chlorophyll content, root length and dry weight. This endophyte has a potential to be used biological control against Phytophthora capsici. Thus it can be used as a safer antifungal application as a part of integrated disease management in C. annum