西瓜枯萎病颉颃菌的筛选研究

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。

Screening of Bacterial Antagonists against Fusarium Wilt of Watermelon

68 strains of fluorescent baeteria from rhizospheres and healthy root tissues of watermelon were isolated on King's MediumB(KB)agar.Of the 68 strains,80.88% showed strongly antagonistic effecton Fusarium oxysporum f.sp.niveum on PDA plates.Conidium germination was significantly inhibited by three strains and the metabolites of 13 strains.52.08% of the strains inhibited the colonization in the vessels of water melon seedlings by Fusarium oxysporum f.sp.niveumto varying degrees.23.53% of the strains grew well on colloidal chitin agar(CA).As seed treatments,strains A63,A51 and A41 suppressed wilt incidence in field soil infected with Fusarium oxysporum f.sp. niveum at 10³-10⁵ cfu/g of soil and strains D33,A61 and A63 improved the growthof watermelon plants.