Prevalence of Trichoderma species in soils of Delhi and its neighbouring states.

摘要

A survey was conducted from January 2004 to July 2006 to determine the prevalence of different species of Trichoderma in the soils of Delhi (IARI farm), Uttar Pradesh (Bagpat and Ghaziabad) and Haryana (Sonipat), India. Soil samples collected at 2-10 cm deep were mixed with distilled water, and shaken. After settlement of soil particles, 1 ml of the supernatant was inoculated on potato dextrose agar medium, and cultured. Total colony forming units were recorded and the cultures were segregated into groups of presumptive species. The maximum population of Trichoderma (1.05x103 /g air dried soil) was recorded in the soil of IARI farm in New Delhi, followed by Bagpat-Kakorkhurd (Uttar Pradesh). T. harzianum and T. viride made up 24.3 and 18% of the total Trichoderma isolates obtained, respectively. The highest number of Trichoderma species was recorded from IARI farm and Sonipat-Begga (8 species), followed by Bagpat-Kakorkhurd (7 species), Bagpat-Sunhera and Ghaziabad-Garh Mukteshwer (6 species), and Ghaziabad-Noli (5 species). The occurrence of Trichoderma species in the soil water significantly influenced by soil texture and structure, nutrient and environmental condition of the soil. In uncultivated systems, inland soil appeared to harbour higher populations of Trichoderma than coastal soil.