Genetic and metabolic diversity of Trichoderma: a case study on South-East Asian

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Genetic and metabolic diversity of Trichoderma: a case study on

South-East Asian isolates

Christian P. Kubicek, , a, Bissettb, 1, Irina Druzhininaa,

Cornelia Kullnig-Gradingera and Szakacsc

a Microbial Biochemistry and Gene Technology Group, Institute of

Chemical Engineering, Technical University of Vienna, Getreidemarkt

9/166, A-1060, Vienna, Austria

b Agriculture and Agri-Food Canada, Eastern Cereal and Oilseed

Research Center, Central Experimental Farm, Ottawa, Ont., Canada K1A

0C6

c Department of Agricultural Chemical Technology, Technical

University of Budapest, 1111, Budapest, Gellert ter 4, Hungary

Received 17 June 2002; accepted 22 October 2002. ; Available online

7 January 2003.

Abstract

We have used isolates of Trichoderma spp. collected in South-East

Asia, including Taiwan and Western Indonesia, to assess the genetic

and metabolic diversity of endemic species of Trichoderma. Ninety-

six strains were isolated in total, and identified at the species

level by analysis of morphological and biochemical characters

(Biolog system), and by sequence analysis of their internal

transcribed spacer regions 1 and 2 (ITS1 and 2) of the rDNA cluster,

using ex-type strains and taxonomically established isolates of

Trichoderma as reference. Seventy-eight isolates were positively

identified as Trichoderma harzianum/Trichoderma inhamatum (37

strains) Trichoderma virens (16 strains), Trichoderma spirale (8

strains), Trichoderma koningii (3 strains), Trichoderma atroviride

(3 strains), Trichoderma asperellum (4 strains), Hypocrea jecorina

(anamorph: Trichoderma reesei; 2 strains), Trichoderma viride (2

strains), Trichoderma hamatum (1 strain), and Trichoderma ghanense

(1 strain). Analysis of biochemical characters revealed that T.

virens, T. spirale, T. asperellum, T. koningii, H. jecorina, and T.

ghanense formed clearly defined clusters, thus exhibiting species-

specific metabolic properties. In biochemical character analysis T.

atroviride and T. viride formed partially overlapping clusters,

indicating that these two species may share overlapping metabolic

characteristics. This behavior was even more striking with T.

harzianum/T. inhamatum where genotypes defined on the basis of ITS1

and 2 sequences overlapped significantly with adjacent genotypes in

the biochemical character analysis, and four strains from the same

location (Bali, Indonesia) even clustered with species from section

Longibrachiatum. The data indicate that the T. harzianum/T.

inhamatum group represents species with high metabolic diversity and

partially unique metabolic characteristics. Nineteen strains yielded

three different ITS1/2 sequence types which were not alignable with

any known species. They were also uniquely characterized by

morphological and biochemical characters and therefore represent

three new taxa of Trichoderma.

Author Keywords: Trichoderma; Biodiversity; Molecular phylogeny;

Biolog; Hypocrea

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