Control of Fusarium disease using antagonistic actinomycetes : 5. Mechanisms of control of radish yellows with microbial inoculum (Material A)

拮抗能を持つ放線菌を利用したフザリウム病害の抑制 : (第5報) 拮抗微生物資材Ａによるダイコン萎黄病抑制機構

Control of Fusarium disease using antagonistic actinomycetes : 5. Mechanisms of control of radish yellows with microbial inoculum (Material A)

Creators Takaki Shigeki

Creators Kitamura Akira

Creators Marumoto Takuya

Creators Tanaka Shuhei

Creators Nishiyama Masaya

Creators Ishida Daisaku

Mechanisms of control of radish yellows by using a microbial inoculum (Material A) which contains antagonistic Actinomycetes against Fusarium oxysporum f. sp. raphani with an organic carrier were investigated. First, a method for determining the chlamydospore density of F. oxysporum in soil was newly developed to enable a more accurate determination of the chlamydospore density in soil. Secondly, the effect of Material A on the control radish yellows was examined in pot experiments. The suppressive effect of Material A varied with the time of application and sowing. Material A did not exert a significant effect on the total Fusarium density but increased the density of the chlamydospores in soil. The disease was well controlled in the soil where the density of chlamydospores was high and that of infection forms, mycelia and conidia, of the fungus was low at the time of sowing. Thirdly, the effect of Material A on F. oxysporum was examined in Petri dishes. Material A suppressed the germination of chlamydospores and subsequent hyphal growth, resulting in a high density of chlamydospores and subsequent hyphal growth, resulting in a high density of chlamydospores in soil. The results obtained suggest that the enhancement of soil fungistasis is one of the mechanisms of control of radish yellows by Material A.

[ISSN]0912-2184

[NCID]AN00352796