Examination of Chitinolytic Bacteria in Alginate-Chitosan Encapsulation on Chili Seed Against Damping off Caused by Fusarium oxysporum

Abstract

One alternative in biological control of plant pathogenic fungi is to provide biological agent inoculant in coated seed. This study was to evaluate potential control and viability of two chitinolytic bacteria, Enterobacter sp. BK15 and Bacillus sp. BK17 of alginate-chitosan encapsulation coated on chili seed against damping off caused by Fusarium oxysporum. Chili seed beads were stored at refrigerator and room temperature. Examination of the bacteria ability in reducing seedling off was conducted by growing and treating the seed beads with F. oxysporum inoculum. Bacterial cell viability was measured by growing grinded chili bead in minimum salt medium with chitin as sole C source. Re-isolation of infected seedling was done by growing it in potato dextrose agar. The result showed that the bacteria in alginate-chitosan coated seeds reduced chili damping off. Chili seedling height and dry-weight did not differ with those of (-) control, treatment with no bacterial and fungal inoculation and differed with (+) control, treatment of fungal inoculation only. Re-isolation of infected seedling showed similar fungal characterization of inoculated F. oxysporum. Bacterial cell viability decreased significantly in 30 days of storage both at refrigerator and room temperature. However, cell viability stored at refrigerator was higher rather than that of room temperature.