Species pattern, genetic diversity and biocontrol potential of Trichoderma in Sardinia

• Published in: Journal of plant pathology 2004-12, Vol.86 (4), p.309-309
• Main Authors: Balmas, V, Scherm, B, Cozzolino, CA, Fiori, S, Druzhinina, I, Kubicek, C P, Migheli, Q
• Format: Article
• Language: English
• Subjects: Phage M13; Rhizoctonia solani; Trichoderma tomentosum; Vicia faba
• ISSN: 1125-4653

We investigated the occurrence and biodiversity of Trichoderma spp. from three undisturbed soil ecosystems in Sardinia, Italy. Seventy-two isolates were identified at the species level by sequence analysis of their internal transcribed spacer regions 1 and 2 (ITS1 and ITS2) of the rDNA cluster and by microsatellite-primed PCR based on the phage M13 core sequence. For some of the isolates, a fragment of the translation elongation factor 1a (tef1) gene was also sequenced. Forty-nine isolates were positively identified as T. harzianum, three each as T. tomentosum and T. hamatum, one each as T. spirale and T. koningii. Ten isolates belonged to the Hypocrea rufa complex (anamorph T. viride). Five isolates showed peculiar ITS1 and 2 as well as tef1 sequences and M13 amplification profiles, and possibly represent a new taxon of Trichoderma. Sixty-seven Trichoderma isolates were tested for their biological control potential. Fourteen strains (the majority of which did not belong to the harzianum species) showed remarkable antagonistic properties when tested in a mini-pot assay under glasshouse against Rhizoctonia solani on Vicia faba, leading to complete emergence of the seedlings even in the presence of very high disease pressure.