Seed transmission of Corynespora melonis, causal fungus of target leaf spot, on cucumber.

Two types of seed transmission of Corynespora melonis on cucumber were confirmed by the transmission tests used artificially inoculated and home-raised seeds. One is ectoparasitism or simple adhesion of the pathogenic fungus to the surface of seeds, the other is endoparasitism where the location of the fungus in the seed is inside the testa as resting mycelia. Such affected seeds occur inferior germination and occasionally damping-off. Cucurbit leaf beetle, Aulacophora femoralis Motschulsky, feeds on the surface of cucumber fruit and promotes infection of the fungus.