いもち病菌によるソラマメ赤色斑点病の交叉防御

Effect of pre-inoculation with Pyricularia spp. on lesion formation of Botrytis fabae Sardina in broad bean was observed. When a spore suspension (<10>^^^6 spores/ml) of Pyricularia oryzae Cavara was previously inoculated to broad bean plant, the size and number of lesions by B. fabae in the pre-inocolated leaves were significantly reduced as compared with those in the uninoculated leaves (control). Such phenomenon was observed in broad bean leaves previously inoculated with solates of Pyricularia sp. from rice, crabgrass, Italian ryegrass or mioga plants. However, protection was not induced in broad bean, when spores of P. oryzae (isolate Hoku 1) which had been heated at 100℃ for 60 hr were pre-inoculated. The fact that Pyricularia spp. can elicit highly effective protection against B. fabae, lead to the conclusion that Pyricularia spp. are useful tools for the practical control of plant diseases.