CAJ | 학술논문

用传统方法从患病山女鳟体表病灶部位分离纯化一株致病性水霉菌株，将其命名为SN，并对其生物学特性进行研究。通过观察附着在油菜籽上水霉菌的形态，其菌丝有适量的分支，呈透明管状，无横隔；菌丝顶端产生棒状孢子囊，游动孢子成熟后，从孢子囊中迅速释放，新孢子囊以层出方式或侧生出芽方式发生。在一定的生长条件下，菌丝顶端或中间可见球形或不规则形状的厚垣孢子。通过与GenBank基因库中水霉属菌株ITS rDNA序列的同源性比较，确定SN菌株与鲑菌株（ GenBank 登录号EU551152）的亲缘关系最近。因此，结合形态特征及ITS序列鉴定结果，可推测菌株SN为鲑水霉（ Saprolegnia salmonis）。研究不同生长条件对菌株的生物学特性的影响，菌株SN的适宜生长温度为10～30℃，最适生长温度为25℃；适宜pH为5～11，最适生长pH为8；适宜盐度为0．5％～2％，最适生长盐度为0．5％。通过分离鉴定山女鳟水霉病致病性病原，并对其生物学特性进行初步研究，为冷水鱼水霉病的防治提供理论依据。
용전통방법종환병산녀준체표병조부위분리순화일주치병성수매균주，장기명명위SN，병대기생물학특성진행연구。통과관찰부착재유채자상수매균적형태，기균사유괄량적분지，정투명관상，무횡격；균사정단산생봉상포자낭，유동포자성숙후，종포자낭중신속석방，신포자낭이층출방식혹측생출아방식발생。재일정적생장조건하，균사정단혹중간가견구형혹불규칙형상적후원포자。통과여GenBank기인고중수매속균주ITS rDNA서렬적동원성비교，학정SN균주여해균주（ GenBank 등록호EU551152）적친연관계최근。인차，결합형태특정급ITS서렬감정결과，가추측균주SN위해수매（ Saprolegnia salmonis）。연구불동생장조건대균주적생물학특성적영향，균주SN적괄의생장온도위10～30℃，최괄생장온도위25℃；괄의pH위5～11，최괄생장pH위8；괄의염도위0．5％～2％，최괄생장염도위0．5％。통과분리감정산녀준수매병치병성병원，병대기생물학특성진행초보연구，위랭수어수매병적방치제공이론의거。
The isolation of the fungal strain from the Oncorhynchus masou masou lesion site through tradi?tional methods is named SN, and its biological characteristics. Observation of the strain attached to rapeseed showed that its hyphae was diaphanous tubular,without diaphragm and moderately branched;clavate sporangia produced at the top of the hyphae,mature zoospores were discharged from the sporocyst rapidly.New sporangia generated from the base of old sporangia by the way of internal proliferation or by basipetalous succession.In a suitable growth environment intermediate spherical or irregularly shaped chlamydospores oppeared at the top of the hyphae.Homology comparison of the ITS rDNA sequences of Saprolegnia sp.in GenBank,showed its closest relationship with Saprolegia salmonis ( GenBank accession number:EU551152) Therefore,combined with mor?phological characterization with phylogenetic analysis based on ITS rDNA sequence,strain SN was identified as Saprolegnia salmonis.This study investigated the effects of different growth conditions on the biological charac?teristics of strains.The strain SN could grow at 10-30 ℃,pH 5-11 and NaCl 0.5%-2%,and its optimum growing temperature,pH and NaCl were 25℃,7,0.5%,respectively.The pathogen of Oncorhynchus masou ma?sou saprolegniasis was isolated and identified in the present study,and its biological characteristics were pre?liminarily studied,which provides a theoretical basis for the prevention and treatment of cold?water fish fungus.