친환경 유기농장 토양에서 분리한 생육촉진근권세균 Chryseobacterium sp.의 생리활성 연구
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Farming area and number of farmers certified to Environmentally-Friendly Certification(hereinafter referred to as Environmental certification: EC) have been increased significantly because of active measures to expand certification and demand public interest for safe agricultural products. Environmentally-friendly materials have been developed and come into wide use for agriculture, but biopesticides that are needed by Environmentally-friendly farmers are few move short to be used so far. Almost 5,000 cases per annum are gotten punished because of use of synthetic pesticides that are prohibited for EC. To solve these problems, this study was conducted for use of Plant Growth Promoting Rhizobacteria(PGPR) promoting plant growth and preventing plant disease to aid environmentally-friendly agriculture. PGPR was selected from farms certified to environmental certification for competence. Soil samples were collected from environmental friendly farms. Fifty eight strains of bacteria having cellulase producing ability were first screened. Selected 58 strains were used to investigate auxin and siderophore production. Of them, only one strain that has produced auxin and siderophore was selected. The strain was identified as Chryseobacterium sp. by using the 16S rRNA sequnece and maldi-tof ribosomal protein sequence. Chryseobacterium balustinum's PGPR effect has already been reported by Marta S. Dardanelli etc. Auxin production by Chryseobacterium sp. was checked by TLC and HPLC. Auxin was produced at lest of 8.43(㎍ / ㎖ tryptophan amusemded medium). Growth promoting activity for lettuce root was best at 108 CFU/㎖. Lettuce rooting number was 3.5 times higher than controls. Effect on root growth of Lettuce and radish was 1.7 and 2.3 times higher than that of the controls. However increased stem growth were negligible. Emergence of 1st and 2nd leaf of Chryseobacterium sp. treated radish was 5days faster than that of control. To check that bacteria competence to roots aseptic condition and general bed soil were investigated . The bacteria was adhered well at root. In order to use Chryseobacterium sp. found from the environmentally-friendly soil, it is essential to check farther the antagonistic ability against the pathogens for using it in the environmenallyt-friendly farming.