Promotion of Tomato Plant growth by Chitosan and Alginate Immobilized Methylobacterium oryzae CBMB20 under Greenhouse Consitions = Promotion of Tomato Plant growth by Chitosan and Alginate Immobilized Methylobacterium oryzae CBMB20 under Greenhouse Consitions

다국어 초록 (Multilingual Abstract)

The formulation of plant growth promoting bacteria as a potential bioinoculant to combat against various biotic and abiotic stresses have been shown to be beneficial for both plants and environment. The industrial application and market value of bioinoculants compared to conventional fertilizers are not high. The major limitations are low quality and the lack of applicable formulation for bioinoculants. These bioinoculants need proper carrier materials for delivery into the agricultural lands for their enhanced functionality, survivability and increase in their shelf life during storage. This study was conducted to compare the plant growth promoting effects of immobilized M. oryzae CBMB20 in chitosan and alginate beads on tomato plant under greenhouse conditions. The immobilized M. oryzae CBMB20 in various formulations were c ted in tomato (Solanum lycopersicum) seeds using 1% (w/v) carboxymethyl cellulose as an adhesive. Various physiological properties of plants such as plant length, dry weight of root and shoot, etc were measured after 15 days of transplanting. The survivability of M. oryzae CBMB20 and degradation of carrier material in soil was checked in regular intervals during the growing stage of tomato plant. The application of chitosan immobilized M. oryzae CBMB20 indicated up to 1.3 fold increase in the shoot and root lengths as well as plant dry weight of tomato plant under greenhouse condition compared to other treatments. The chitosan treated tomato seeds showed significant increase in germination percentage and chlorophyll content. Immobilized M. oryzae CBMB20 showed 1.5 fold higher survivability in tomato rhizosphere soil compared to free cells with around 4.35 log CFU g^-1 of soil for chitosan at 21 DAS. The alginate beads got fully degraded whereas there was partial degradation of chitosan beads after 30 days. Chitosan was able to keep a considerable survivability of M. oryzae CBMB20 for over 20 days. These observations confer that chitosan is more suitable carrier material for immobilizing M. oryzae CBMB20. Furthermore, such formulation holds good promise to be utilized with other PGPB strains and crops for potential large scale application in agricultural fields.