KOMARIATUL ANJANI, HADIWIYONO AND AHMAD YUNUS
Agrotechnology Department, Faculty of Agriculture, Universitas Sebelas Maret, Ir. Sutami Street 36 A, Surakarta (Solo) 57126, Indonesia
*(e-mail : yunus.uns7@yahoo.com; Mobile : 6281548673060)
(Received : May 12, 2019; Accepted : July 15, 2019)
ABSTRACT
The problem of Cercospora janseana attacks that causes narrow brown spots in rice needs to be considered. Control of pathogens with fungicides is not environmentally-friendly. Alternative controls using biological control agents such as endophytic bacteria need to be assessed. This study aimed at determining the antagonism ability of artemisia endophytic bacteria towards C. janseana at in vitro and in vivo tests. The research methods included the isolation of endophytic bacteria from the leaves of Artemisia annua, pathogenicity test through hypersensitivity reactions, KOH test, identification of morphology and cell shape of endophytic bacteria and inhibitory test in vivo of endophytic bacteria. Five endophytic bacteria were successfully isolated. BEA12 had the highest inhibitory ability at antagonism in vitro test. Abnormal hyphae such as swelling hyphae like chlamydospore formed in C. janseana with BEA5 and BEA12 treatment also curling hyphae formed in C. janseana with BEA2 treatment indicated that endophytic bacteria produced secondary metabolite compound or antibiotic. BEA4 was not able to inhibit C. janseana at antagonism in vitro test but, it had disease inhibition ability at in vivo test. Inhibition mechanism of C. janseana by endophytic bacteria was through secondary metabolite compound or antibiotic production, or inducing host resistance. The effectiveness of diseases inhibition by endophytic bacteria was fluctuated.
Key words : Antagonism, narrow brown leaf spot, Cercospora janseana