Screening of endophytes from rubber trees (Hevea brasiliensis) for biological control of Corynespora cassiicola

Abstract

With 28 samples of foliage and sapwood of Hevea brasiliensis collected from Ho Chi Minh city, Binh Phuoc province, Binh Duong province (Vietnam), we isolated and screened endophytes antagonistic to Corynespora cassiicola Berk. & Curt, the agent of Corynespora Leaf Fall disease. As a result, 21 strains of endophytic bacteria, 14 strains of endophytic fungi and Corynespora cassiicola pathogenic fungus were isolated.  Through resistance testing by dual testing method between endophytes and C. cassiicola, the results showed that T9 and T16 strains have inhibited C. cassiicola.  In the C. cassiicola-inhibited concentration testing by bacterial filtrate, T9 and T16 strains inhibited C. cassiicola at the rate of 100% at the concentration of 1:1. In the testing of ability to kill C. cassiicola, T9 and T16 strains killed C. cassiicola after 3 times of spraying bacterial filtrate. T9 and T6 strains were identified by biochemical methods, having similar characteristics to Bacillus thuringiensis.