Uji aktivitas biokontrol bakteri endofitik kentang terhadap Erwinia sp. dan Fusarium sp.

Abstract

Erwinia sp. and Fusarium sp. are pathogens that can decrease the production and quality of potatoes. The alternative ways to control pathogen attack by using the endophytic bacteria. This study aimed to test the biocontrol activity of potato endophytic bacteria (WT25, G053, G0169, and L12) against Erwinia sp. and Fusarium sp. Three test were conducted during this study: (1) The anti Qourum sensing (QS) test against Chromobacterium violaceum and Erwinia sp. (2) the test of Volatile Organic Compounds (VOCs) against Fusarium sp. and (3) the in vitro and in planta challenge test of Fusarium sp. using tobacco. The result of QS test against C. violaceum showed all isolates of endophytic bacteria inhibited violacein formation. The WT25 isolate had the largest inhibitory index of violacein formation which was 0.44. The diameter of no purple zone was 1.87 cm. Anti-QS test against Erwinia sp. showed that all endophytic bacteria were able to inhibit the decomposition of potato tubers. The VOCs emitted by endophytic bacteria. The VOCs were able to inhibit the mycelial growth of Fusarium sp.. G0169 isolate had the highest inhibition index. The challenge test against Fusarium sp. resulted all isolates were able to inhibit the mycelial growth of Fusarium sp. The In planta of tobacco plants had proved the inoculation of endophytic bacteria in the rhizosphere decreased the Fusarium sp. wilt symptoms. Based on these results we concluded four potato endophytic bacteria (WT25, L12, G0169, and G053) potentially to be developed as plant disease biocontrol agents caused by Erwinia sp. and Fusarium sp.