CAJ | 학술논문

为获得对水稻纹枯病有生防效果的拮抗放线菌，以水稻纹枯病菌(Rhizoctonia solani )为指示菌，从湖南郴州天鹅山风景区土样中分离筛选出5株拮抗放线菌株，其中菌株 CZB40无菌滤液的5倍稀释液对指示菌菌丝生长抑制率高达90.45%，能使菌核菌丝萌发指数降低56.30%，而且能显著抑制菌核的形成。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 CZB40菌株鉴定为极暗黄链霉菌(Streptomyces fulvissimus )。抗菌谱研究表明，该菌株对稻瘟病菌(Magnaporthe grisea )、桃褐腐病菌(Monilinia fructicola )、辣椒疫霉病菌(Phytoph-thora capsici )、草莓灰霉病菌(Botrytis cinerea )和辣椒白绢病菌(Sclerotium rolfsii )都有拮抗作用，抑菌率达27.94%~85.71%。通过单因子变量法和均匀设计法对菌株 CZB40进行发酵条件研究。结果表明，其最佳的发酵条件为：玉米粉25 g/L、酵母粉5 g/L、MgSO40.2 g/L、NaCl 0.8 g/L、K2 HPO40.4 g、水1000 mL、29℃、pH 6.0。经优化后，菌株 CZB40无菌滤液的10倍稀释液对水稻纹枯菌丝生长抑制率最高，达到94.85%，比优化前明显提高。该研究结果为水稻纹枯病的生物防治提供科学依据。
위획득대수도문고병유생방효과적길항방선균，이수도문고병균(Rhizoctonia solani )위지시균，종호남침주천아산풍경구토양중분리사선출5주길항방선균주，기중균주 CZB40무균려액적5배희석액대지시균균사생장억제솔고체90.45%，능사균핵균사맹발지수강저56.30%，이차능현저억제균핵적형성。경형태관찰、배양성상、생리생화감정，병결합16S rDNA 서렬분석，장 CZB40균주감정위겁암황련매균(Streptomyces fulvissimus )。항균보연구표명，해균주대도온병균(Magnaporthe grisea )、도갈부병균(Monilinia fructicola )、랄초역매병균(Phytoph-thora capsici )、초매회매병균(Botrytis cinerea )화랄초백견병균(Sclerotium rolfsii )도유길항작용，억균솔체27.94%~85.71%。통과단인자변량법화균균설계법대균주 CZB40진행발효조건연구。결과표명，기최가적발효조건위：옥미분25 g/L、효모분5 g/L、MgSO40.2 g/L、NaCl 0.8 g/L、K2 HPO40.4 g、수1000 mL、29℃、pH 6.0。경우화후，균주 CZB40무균려액적10배희석액대수도문고균사생장억제솔최고，체도94.85%，비우화전명현제고。해연구결과위수도문고병적생물방치제공과학의거。
To obtain antagonistic actinomycetes for biocontrol of rice sheath blight,five antagonistic actinomyce-tes strains were isolated from soil samples in Chenzhou Swan Mountain of Hunan Province.Among these samples, the 5× diluted sterile filtrate of CZB40 strain exhibited the highest antagonistic activity,showing 90.45% myceli-al growth inhibition and leading to decrease of mycelial germination index by 56.30%.In addition,the formation of sclerotia could be significantly inhibited.By studying the morphology,culture characteristics,physiological,bi-ochemical tests and 1 6S rDNA analysis,CZB40 was identified as Streptomyces fulvissimus .Further antimicrobial spectrum research demonstrated that the strain CZB40 had antagonism against Magnaporthe grisea ,Monilinia fructicola ,Phytophthora capsici ,Botrytis cinerea and Sclerotium rolfsii ,with the inhibition rate from 27.94% to 85.71%.The fermentation conditions were optimized by using the method of one variable and uniform design. The optional fermentation conditions for antibacterial substance production of CZB40 were shown as followed:corn flour 25 g,yeast 5 g,MgSO4 0.2 g,NaCl 0.8 g,K2 HPO4 0.4 g,water 1 000 mL,fermentation temperature 29 ℃ and pH 6.After optimization,the mycelial growth inhibition rate increased significantly up to 94.85% with 10 times sterile filtrate compared with previous fermentation conditions.The results provided scientific evidence in biocontrol of rice sheath blight.