[5-1130-P] Other Categories (5th)

[5-1130-P-21] Screening and Identification of Endophytic Bacteria from Thai Organic Rice for Plant Growth Promotion

*Somkid Deejing¹, Witchayaporn Pawong¹ (1. Program in biotechnology, Faculty of Science, Maejo University, Sansai, Chiang Mai(Thailand))

Keywords:Endophytic bacteria, Indole acetic acid, Organic agriculture, Bacterial characteristics

Endophytic bacteria are able to colonize in plant tissues without causing harmfulness subsequently, sharing and exchanging beneficial metabolites to plant hosts. Plant growth can be promoted by these bacteria via their phytohormones i.e. indole acetic acid (IAA) and/or enhancement of nutrient availability. IAA is associated with plant cell division, cell elongation and lateral root formation. The population of endophytic bacteria are more diverse in crops planted following to organic practice. Thus, organic crops are interesting sources for endophytic isolation for further agricultural application as plant growth promoter. The aims of this present work were to isolate and identify promising endophytic bacteria from various part of rice with respect to their IAA production. Rice tissue samples were collected from five-year-old organic farm in Chiang Mai, Thailand. Bacteria were cultured on Plate count agar (PCA), Pikovskaya ’s medium (PVK), Tryptic soy agar (TSA) and International Streptomyces project (ISP₂). The results showed that 53 bacterial isolates were obtained and further screened for IAA production in medium containing 0.2 % tryptophan. The IAA producing bacteria were RRSPCA and LRSPCA2 which produced at 20.93 and 7.12 mg/L, respectively. They were identified as Pseudomonas sp. and Chryseobacterium kwangyangense, respectively, based on 16s rRNA gene sequencing at 100 % similarity. These endophytic bacteria in this study could be applied for enhancing a plant growth, resulted a plant yield. Moreover, their bioactive compounds could be used for biotechnological applications. Therefore, the endophytic bacteria will contribute to organic agriculture for more environmentally sustainable in the future.