Effect ofGlomus intraradiceson infection byFusarium oxysporumf.sp.radicis-lycopersiciin tomatoes over a 12-week period

摘要

The interaction betweenGlomus intraradicesSchenck amp; Smith, a vesicularndash;arbuscular mycorrhizal fungus, andFusarium oxysporumSchlecht f.sp.radicis-lycopersiciJarvis amp; Shoemaker and its effect on tomato plants were investigated over a 12-week period. The root colonization byGlomuswas not affected by the presence ofFusarium. The number ofFusariumpropagules was consistently lower when the plants were inoculated withGlomus. The presence ofGlomusdecreased root necrosis caused byFusariumin weeks 5, 11, and 12, but no significant effect was observed for the other 9 weeks. The results obtained at any observation time for the endomycorrhizal colonization and theFusariumpopulation, but not for the percent of root necrosis evaluation, were consistent throughout the 12-week experiment. It is concluded that the parameters used to study the interaction between a vesicularndash;arbuscular mycorrhizal fungus, a fungal root pathogen, and a host plant must be measured at different times after inoculation with the pathogen to make sure that observations are representative of the interaction under study.