Phaeotheca dimorphosporaincreasesTrichoderma harzianumdensity in soil and suppresses red pine damping-off caused byCylindrocladium scoparium

摘要

A fungal antagonist,Phaeotheca dimorphospora, was tested for its ability to control damping-off of red pine (Pinus resinosa) caused byCylindrocladium scoparium. In vitro, the germination of seeds coated withP.dimorphosporamicroconidia was significantly increased by 10 compared with uncoated seeds. In experiments carried out in Petri dishes, addition ofP.dimorphosporainto soil significantly reduced the population ofC.scopariumand disease incidence. In the greenhouse, application ofP.dimorphosporainto the top layer of soil reduced pre- and post-emergence damping-off by 79.5. Under greenhouse conditions,P.dimorphosporastimulated the population ofTrichoderma harzianum, a well-known antagonist of soil-borne plant pathogens. In soil treated withP.dimorphospora, the number of propagules ofT.harzianumwas 100ndash;500 times higher than in the untreated control, whereas the population ofC.scopariumdecreased rapidly and was not detectable 1 month after sowing.Key words:Phaeotheca dimorphospora,Trichoderma harzianum,Cylindrocladium scoparium, damping-off, biological control, fungal antagonist,Pinus resinosa.