Abstract: The genus Ceratocystis produces a range of flavoring compounds,in this study,strains PP1-1PG and WYB were compared on the basis of characteristics of colony morphology and ITS sequences.The volatile components were analyzed by gas chromatography-mass spectrometry (GC-MS).Septate mycelia were observed on PSA substrates for both strains.Based on the ITS phylogeny,strain PP1-1PG was clustered with Ceratocystis fimbriata-forming a distinct clade while strain WYB was clustered with Ceratocystis paradoxa.Analyzing the volatile components by GC-MS,it is known that the most materials produced by two strains were ethyl acetate,isobutyl acetate and styrene,which the relative contents of ethyl acetate and isobutyl acetate were 45.85% and 61.02% in two strains.Benzaldehyde,a widely used flavour substance,was detected from strain PP1-1PG for the first time,providing chemical basis and foundation for the comprehensive development and the search for this substance.

Key words: Ceratocystis spp., ITS sequence, volatile compounds, GC-MS analysis