Molecular Characterization of Trichoderma harzianum isolates from different Agroclimatic Zones of Karnataka.

Abstract

Trichoderma species are the fungi that are present in nearly all soils and other diverse habitats. Trichoderma are common and are relatively easy to isolate and culture. In addition, isolates grow quickly on many substrates, produce metabolites with demonstrable antibiotic activity, and may be mycoparasitic against a wide range of pathogens (Grondona et al., 1997). Among Trichoderma genera Trichoderma harzianum is both plant growth promoter as well as antagonist against many pathogenic fungi. An effort was made to isolate ten isolates of Trichoderma harzianum from soil samples collected from different agroclimatic zones of Karnataka. A total of ten Trichoderma isolates representing each agroclimatic zone was isolated using Potato dextrose agar medium and purified. The fungal isolates were subjected to morphological tests and characterized as listed in The Manual of Soil Fungi (Gilman, 1961). Colony morphology and microscopic observation confirmed that all isolates belonging to the Trichoderma harzianum. Molecular diversity of ten isolates of Trichoderma harzianum was characterized by using SDSPAGE and RAPD markers. The data on the protein banding patterns of Trichoderma harzianum isolates were presented based on relative mobility value (Rm), squared euclidean distances and intensity of the bands. In RAPD a total of 125 bands were scored out of which 100 bands were found to be polymorphic (80%). Statistical analysis of both SDS-PAGE and RAPD data enabled the classification of 10 T.harzianum isolates in to two major groups. Thus SDS-PAGE and RAPD banding pattern of these isolates could easily distinguish the isolates of different zones.