Biocontrol Potential of Trichoderma Spp. Aganlst Fusarium Oxysporum

Abstract

Trichoderma spp., are free-living. fungi that are common in -soil and root ecosystems. The filamentous fungal genus Trichoderma are well known as potential candidates for the biological control of plant pathogenic fungi and produces several hydrolytic enzymes for. biotechnological importance. They are highly interactive in root, soil and foliar ecosystem. Under present investigation a total of 25 soil samples were collected from the rhizospheric and non-rhizospheric soil from different crops and various. locations. Isolation ·of Trichoderma was made using serial dilution techniques. Seventeen native isolates of Trichoderma spp were isolated and identified for the present study. On the basis of Colony characters, growth rate in culture., pigmentation, and colour of conidia. are the important characters used to distinguish different species of Trichoderma . Initially On the basis of cultural and morphological characteristics Trichoderma spp. were identified as T. koningii, T.-Harzianum and T. viride. Among. them three isolates were ider.~tified as T. koningii; eleven isolates were T. harzianum and two isolates were identified as T. viride and one isolate is still unidentified. For . molecular characterization ITS analysis were used. The DNA of eight isolates were extracted. using modified.·CTAB methods. A total eight isolates among them were used for ITS analysis Internal transcribed spacer- 1 region (ITS1) of the ribosomal DNA was amplified by polymerase chain reaction ·(PCR) by using selected universal primers. (ITS1 and ITS4) for eight Trichoderma isolates. The size of PCR product amplified with the primer pair ITS1 and ITS4 ranged from 563-602bp. These 17 isolates also showed different morphology and growth kinetics features The. physical interaction was observed between Trichoderma spp. and Fusarium oxysporum f. sp. Jycopersici from 4th day as both fungus come in contact. The growth of Fusarium oxysporum f. sp. lycopersici was increases upto 4th and 5th day thereafter this was checked by the antagonist at 5th and 7th day. The maximum suppression of the Fusarium oxysporum f. sp. Jycopersici at 7th day was recorded by SVPU-Thar7, which was 81.40 Percent .The minimum suppression of the mycelia growth of the Fusarium oxysporum f. sp. Jycopersici was show by SVPU-Thar4 (57.05 percent). These results will be useful to develop a potential biocontrol agent for plant diseases.