1995 Volume 46 Pages 71-77
Among a total of 110 fluorescent bacterial isolates cultured on King's B agar medium, that originated from the rhizosphere soil of asparagus, 8 strains showed antibiosis against Fusarium moniliforme var. intermedium on potato dextrose agar (PDA) medium. These isolates also inhibited the occurrence of crown rot of asparagus in a greenhouse assay, and three strains were designated as antagonists. Two antagonists, RSA 1 and RSA9, also induced root growth promotion in asparagus seedlings in noninfected soil, while nonantagonists, RSA 7 and RSA 63, did not promote root growth. Treatment of the seedlings with a culture filtrate of an antagonist RSA 9 not only suppressed crown rot but also promoted root growth. On the other hand, when the seedlings were treated with a culture filtrate of nonantagonists, neither suppression of the disease nor root growth promotion occurred. The antagonists RSA 1 and RSA 9 were identified as Pseudomonas putida (Trev.) Migula.
