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为了探寻辣椒尖孢炭疽病的生防药剂,从而控制该病在辣椒生产上的扩散。以辣椒尖孢炭疽病菌(Colletotrichum acu-tata)为指示菌,从浏阳河风光带土样中分离筛选出6株拮抗放线菌株,其中菌株ND045对指示菌的拮抗效果最好,菌丝生长抑制率高达71.6%。经形态观察、培养性状、生理生化鉴定,并结合16S rDNA序列分析,将ND045菌株鉴定为吸水链霉菌(Streptomyces hygroscopicus)。抗菌谱研究表明,该菌株对稻瘟病菌(Magnaporthe oryzae)、辣椒疫霉病菌(Phytophthora cap-sici)、黄瓜枯萎病菌(Fusarium omysporum)和辣椒白绢病菌(Sclerotium rolfsii)都具有较强的拮抗作用,抑菌率达40.58%～72.00%。通过单因子变量法和均匀设计法对菌株ND045进行发酵条件研究,结果表明,其最佳的发酵条件为:15 g大米粉、5 g大豆粉、0.5 g MgSO4、0.01 g FeSO4.7H2O、1.5 g NaCl、水1 000 mL、30℃、pH 8。经优化后,菌丝生长抑制率最高达到82.61%,比优化前提高了11.01%。该研究结果为辣椒尖孢炭疽病的生物防治提供科学依据。
In order to search for biocontrol agent of anthracnose of spicerles chilli, so as to control the spread of the disease in pepper production. Colletotrichum acu-tata was used as indicator to isolate six strains of antagonistic actinomycetes from the soil samples of Liuyang River Scenery Belt. The strain ND045 showed the best antagonistic effect on indicator bacteria and mycelial growth inhibition Rate up to 71.6%. The strain ND045 was identified as Streptomyces hygroscopicus by morphological observation, culture traits, physiological and biochemical identification and 16S rDNA sequence analysis. Antibacterial spectrum analysis showed that this strain has a strong antagonistic activity against Magnaporthe oryzae, Phytophthora cap-sici, Fusarium omysporum and Sclerotium rolfsii , Antibacterial rate of 40.58% ~ 72.00%. The fermentation conditions of strain ND045 were studied by single factor method and uniform design method. The results showed that the optimum fermentation conditions were 15 g rice flour, 5 g soy flour, 0.5 g MgSO4, 0.01 g FeSO4.7H2O, 1.5 g NaCl, water 1000 mL, 30 ° C, pH 8. After optimization, mycelial growth inhibition rate up to 82.61%, 11.01% higher than before optimization. The results provide a scientific basis for the biological control of Anthracnose.