Screening Of Trichoderma Strains For Biological Control Of Main Turfgrass Diseases In Dalian Golf Courses

As a new industry, the turfgrass growth has developed rapidly in China. Many cities have stressed the lawn areas as a modern city symble. With the rapid increase in turfgrass growing area, various diseases have gradually become the main limiting factor of turf industry in China. The fungal species of the genus Trichoderma have been widely confirmed to be good biological control agents against lawn diseases. These fungi usually express significant antagonism against plant pathogens by means of ocupation of living space, scrambling for nutrients, parasitism, antibiosis, induction of plant resistance and so on. The paper is designed to investigate the fungal species of Trichoderma in turfgrass field in Dalian city and screen for effective biocontrol agents.Totally 45 soil samples were collected in three golf courses for fungal isolation and culture. After fungal isolation by means of soil dilution and plant tissue isolation, totally 78 strains of Trichoderma and two pathogens of Fusarium oxysporum and Rhizoctonia solani were obtained. After dual culture of Trichoderma and the pathogen in PDA plate, 15 strains of Trichoderma were found to show evident biological control effect. After morphological identification and rDNA ITS sequence analysis, eight Trichoderma species were at last identified, namely T. harzianum, T. hamatum, T. asperellum, T. viridescens, T. aureoviride, T. atroviride, T. viride and T. virens.Among the effective Trichoderma strains, strain Th12 of T. hamatum is a good potential bio-control agent against turfgrass Fusarium blight and brown spot diseases. The strain is further investigated for liquid fermentation. The test results show that the optimum liquid fermentation conditions were as follows: glucose as carbon source, peptone as nitrogen source, initial pH 6, seed inoculation amount 0.8ml, 50ml of liquid medium in 250ml flask, shaking speed 180r/min, at 25℃for 3 days. Under the expected conditions the maximum mycelial yield was achieved. The research results provide a useful base for further application of the fungal strain in bio-control of turf grass diseases.