Wang Mei-Qin, Ma Lin, Han Ju-Cai, Liu Hui-Ping, He Yun-Chun
College of Agriculture, Shanxi Agricultural University, Taigu 030801, Shanxi, China.
Ying Yong Sheng Tai Xue Bao. 2012 Sep;23(9):2529-35.
An endophytic actinomycete strain St24 with acaricidal activity was isolated from the root-stem junction of tomato plants, with the taxonomic position of the strain and its control effect against gray mold disease investigated. The St24 was identified as Streptomyces vinaceus, and its broth's petroleum ether extracts could inhibit a variety of pathogens. The inhibitory effect of the extracts on Botrytis cinerea was the strongest, with the EC50 of inhibiting B. cinerea mycelia growth being 11.78 mg x L(-1). After treated with the extracts, the amount of the mycelia decreased, and the mycelia became crenate or broken, with the protoplast extravasated and the tuberculate malformation appeared. The B. cinerea culture treated with the extracts showed the maximum absorption at 260 nm, which was absent in the control, indicating that the St24 extracts increased the pathogens cell membrane permeability. Pot experiment showed that the extracts could protect tomato plants against B. cinerea. Foliar spraying the extracts at 100 mg x L(-1) had the best protective effect, with the controlling effect reached 94.3% after 24 h and 85.4% after 120 h.
从番茄植株根茎交界处分离出一株具有杀螨活性的内生放线菌菌株St24，并对该菌株的分类地位及其对灰霉病的防治效果进行了研究。St24被鉴定为酒红色链霉菌，其发酵液的石油醚提取物能抑制多种病原菌。提取物对灰葡萄孢的抑制作用最强，抑制灰葡萄孢菌丝生长的EC50为11.78 mg·L(-1)。提取物处理后，菌丝数量减少，菌丝变得皱缩或断裂，原生质体外渗，出现瘤状畸形。经提取物处理的灰葡萄孢培养物在260 nm处有最大吸收峰，而对照中没有，表明St24提取物增加了病原菌细胞膜的通透性。盆栽试验表明，该提取物能保护番茄植株免受灰葡萄孢的侵害。以100 mg·L(-1)的浓度叶面喷施提取物具有最佳的保护效果，24 h后的防治效果达到94.3%，120 h后达到85.4%。
