Sesame is a major cooking oil crop in Korea. One of the primary problems in sesame cultivation is low healthy stand establishment due to the occurrence of seedling rot and damping-off resulting from a complex of soil-borne pathogens in the field. To address the problem, the bioformulation of Pseudomonas fluorescens M45 was prepared in powder form using clay and vermiculite, and was evaluated for its effect on biological control of soil-borne pathogens in sesame cultivation. In the petri dish trial, the emergence rate was overall good (> 92%) regardless of seeds being pelleted and/or M45-treated. In both pot and field trials containing disease-conducive soils, seed-pelleting substantially reduced emergence rate, whereas seed-pelleting with M45 significantly improved the emergence rate (> 26%). The emergence rate of sesame seeds treated with the strain M45 was greater than 30% regardless of seed pelletization. We also found that M45r colonized in the roots at the density of 1.6×105 cfu/g. With aid of the bioformulation, however, root colonization of the strain was significantly increased to 4.0×106 cfu/g. The powder formulation with strain M45 enhanced the rate of healthy stand establishment in disease-conducive soil. Therefore, bioformulation with strain M45 is a promising method to overcome problems associated with the successive cultivation of sesame.
이상의 결과를 종합하면, 평가대상 토양을 증류수로 20배 희석하여 200rpm 으로 30분간 진탕한 후 PDA (감자추출배지)와 혼합하여 121℃에서 20분간 살균한 후 Coriolus hirsutus (MKACC 50560) 균을 접종한다. 접종완료 후 25℃에서 5일간 배양한 후 균사 생장을 측정하여 담자균의 균사 생장률 (목적토양에서의 균사생장/PDA 에서의 균사생장×100)을 계산한다. 이 기준에 따라 균사생장률이 60%이상이 되면 대상 토양은 작물 생육에 적합한 토양이라고 추정할 수 있다. 이러한 방법은 토양의 건전성 평가를 위한 신속한 간이검사를 통하여 소량의 시료를 가지고 단기간 내 대량 분석을 가능하게 하여 토양 건정성 평가의 기초 자료로 사용될 수 있다고 사료된다.