摘要
采用平板和离体培养法测定S-921菌株及其发酵液对苹果树腐烂病菌的作用。结果表明,S-921菌对苹果树腐烂病菌有较强的抗生作用,二者在PDA平极培养基上共同培养时,能产生直径30～40mm的抑菌圈。将苹果树腐烂病菌用S-921菌株发酵液浸泡处理12小时,可失去致病能力。离体培养的结果表明,刮除病斑后涂抹S-921菌株发酵液的治疗效果最好,治愈率达100％;在病斑处划刻(间隔2～3mm)后涂抹的,仅能短时期的抑制病斑扩大,不能治愈。S-921菌发酵液对苹果树腐烂病菌具有溶菌作用,使原生质凝集,液泡消失,菌丝壁溶解,原生质外流,菌丝体崩溃而解体。
The effects of S-921 strain (Streptomyces aureus) and its fermented broth on apple tree canker, Valsa mali,were tested by plating and free culture methods. The results shown that the S-921 strain had a strong antibiotic effect. An inhibiting circle with a diameter of 30-40 mm was produced on the PDA plate in which the S-921 strain and V. mali were inoculated. V. mali lost its pathogenicity when treated with the fermented broth for 12 hr. Results of the free culture indicated that the best effect was produced when the canker was treated with the fermented broth following scraping off the canker spot. The rate of cure could reach up to 100%. The method of cutting canker spot (2-3 mm apart) and treating with the fermented broth temporarily inhibited the development of canker spot, but the canker was not cured completely. It was found that the fermented broth caused lysis of V. mali. The vacuole of the fungus disappeared, the cytoplasm condensed, the hypha wall broke, the cytoplasm leaked and the fungus' cell degenerated.
