Identification of the Pathogen of Sclerotiniose on Gaillardia pulchella and Screening of Antagonistic Trichoderma Strain

The pathogen was identified based on pathogenicity,disease symptom,cultivation characters and morphology.The antagonistic Trichoderma strain was screened by antagonistic ability tests in vitro and pot experiments.The results showed that pathogen of sclerotiniose on Gaillardia pulchella was identified as Sclerotinia sclerotiorum(Lib) de Bary.Trichoderma harzianum H5 gave the strongest antagonistic ability in vitro and highest control efficiency in pot experiments.Its antagonistic index and control efficiency were Ⅰ and 93.2%,respectively.Among the five tested Trichoderma strains,Trichoderma harzianum H5 had the best control potential for controlling the sclerotiniose on Gaillardia pulchella.