초록
한국의 여러 지역에서 수집 분리 동정한 Bacillus subtilis의 토마토, 고추에 대한생육촉진 및 병 저항성 활성을 평가하였다. 선발된 B. subtillis JE 21-1 와 JE8-1 균주는 토마토 및 고추의 생육을 크게 증진 시켰다. B. subtillis JE21 균주 처리는 무처리 혹은 0.1 mm BTH 처리와 비교하여 고추와 토마토의 초장, 잎의 크기 등 생육을 촉진하고 고추 탄저병의 발생을 억제시켰다. ES2-1 균주는 고추 근권에 정착력이 우수하며 $1.2{\times}10^5cfu/g$ root의 밀도를 나타내었다. 생육촉진은 과실의 크기와 무게로 평가하였는데 JE9-4, ES2-2 균주를 처리하였을 때 과실크기가 향상되었고, JE 3-6, ES4-2, ES2-2 및 JE 21-2를 처리하였을 때 고추과실의 무게가 높았다. PR1a::GUS 유전자 함유 담배(Xanthi nc)에 선발된 바실러스균을 선 정착시키고 무름병균인 Pectobacterium carotovornm SCC를 접종하여 병 저항성 발현을 조사한 결과 JE9-4의 PRI::GUS 발현량이 가장 많았다.
Bacillus subtilis strains isolated from different regions of Korea were screened for their plant growth promotion and induced systemic resistance (ISR) in tomato and red-pepper. The plant growth promotion on red-pepper and tomato revealed maximum plant height (22.73 cm) on red pepper treated with B. subtilis strain JE 21-1 and 30.18cm in case of tomato treated with B. subtilis strain JE 8-1. There was also significant improvement in root and shoot dry weight in both the plants. The strain JE 21-1 showed better promise for all growth parameters in red-pepper and tomato when compared to other strains and positive check BTH. Different strains screened in square plate method also revealed maximum plant height and leaf width, and suppressed anthracnose on red pepper in case of strain JE 21-1 at $10^6$ and $10^7$ cells/ml when compared to other strains. In all the bacterial inoculations the population was significantly high when compared to untreated check. In plant growth promotion with respect to fruit length and weight, fruit length was maximal in treating with JE 9-4 and ES 2-2, while fruit weight was maximal in treating with JE 3-6, ES4-2, ES2-2 and JE 21-2 on red pepper. In case of tomato, comparatively better fruit weight was in JE 21-1, ES 3-3 and JE 10-2 when compared to BTH and untreated control. The soft rot disease caused by Pectobacterium carotovorum SCCI was completely suppressed in case of transgenic tobacco harboring GUS gene related to PR1a and increased the level of salicylic acid significantly in combined application of JE 9-4 on par with BTH. Thus, this study clarified some potential Bacillus subtilis strains for plant growth promotion and ISR in red-pepper and tomato.
