Growth and germination of fungal spores in guttation fluids of barley grown with different nitrogen sources

Abstract

Nitrogen nutrition of barley had no uniform effect on conidial germination of Alternaria alternata, Botrytis cinerea and Cladosporium herbarum in guttation fluids in vitro or on leaves. Sterilized guttation fluids stimulated germination of C. herbarum and hyphal growth of all fungi in vitro, whereas non-sterile fluids lowered percentage germination of C. herbarum and sometimes inhibited hyphal growth of A. alternata and C. herbarum. In another experiment, non-sterile guttation fluids stimulated germination of all fungi. Non-sterile guttation fluid which promoted hyphal growth in vitro had less or no effect on germination on detached leaves. This suggests that factors other than plant nutrition are more important in determining fungal germination in guttation fluids.