西瓜枯萎病颉颃菌的筛选研究

Screening of Bacterial Antagonists against Fusarium Wilt of Watermelon

从健康西瓜根组织和根际土壤中分离到６８个荧光假单胞菌株。８０．８８％的菌株具有较强的皿内颉颃作用；４．４１％的菌株活体和１９．１２％的菌株代谢物明显抑制西瓜枯萎菌分生孢子的萌发；５２．０８％的菌株可以不同程度抑制枯萎菌在瓜苗导管内定殖；２３．５３％的菌株可以利用几丁质作为碳源。用自然的大田土进行温室盆栽试验，Ａ６３，Ａ５１和Ａ４１菌株在各枯萎菌浓度水平下均表现出较好的防病作用。Ｄ３３，Ａ６１和Ａ６３对瓜苗具有明显促进作用。

strains of fluorescent bacteria from rhizospheres and healthy root tis-sues of watermelon were isolated on King′s Medium B(KB)agar.Of the 68 strains,80.88% showed strongly antagonistic effect on Fusarium oxysporum f.sp.niveum on PDAplates.Conidium germination was significantly inhibited by three strains and themetabolites of 13 strains. 52. 08% of the strains inhibited the colonization in the vesselsof watermelon seedlings by F. oxysporum f.sp.niveum to varying degrees.23.53% ofthe strains grew well on colloidal chitin agar(CA).As seed treatments, strains A63,A51 and A41 suppressed wiLt incidence in field soil infected with F. ozysporum f.sp.niveum at 10￣3-10￣5 cfu/g of soil and strains D33,A61 and A63 improved the growth ofwatermelon plants.