Improvement of endophytic bacteria using ion beams and application of bio-pesticide with plant growth promoter made from oligo-chitosan

Aino, Masataka*; Sato, Katsuya; Nagasawa, Naotsugu; Taguchi, Mitsumasa; Narumi, Issey*

The endophytic bacteria produce various kinds of bioactive substances, by which the plants grow well and exhibit resistance to diseases and environmental stress. In this study, 300 isolates that were derived from FPH9601 irradiated with carbon ion beams were tested for inhibitory effect of tomato bacterial wilt. We could successfully obtain 24 mutants that have enhanced suppressiveness against the tomato bacterial wilt. In the meantime, chitosan is a linear polysaccharide composed of randomly distributed -(1-4)-linked D-glucosamine (deacetylated unit) and N-acetyl-D-glucosamine (acetylated unit). Low molecular weight chitosan (oligo-chitosan), which can be obtained by -ray irradiation of chitosan in diluted solutions, has potential uses in agriculture. In the field condition, the suppression effect against the pathogen significantly increased when tomato was treated with oligo-chitosan and endophytic bacteria.