09-08-2013, 03:34 PM
Collection of Trichoderma strains from various regions of Jammu Province
ABSTRACT
Trichoderma species are cosmopolitan fungi frequently present in all types of soil, manure and decaying plant tissues. Their dominance in soil may be attributed to their diverse metabolic capability and aggressive competitive nature. In the present study, soil samples were collected from fields of rice and pulses from various districts of Jammu Province viz. Jammu, Samba, Kathua, Reasi, Udhampur, Rajouri and Doda. A serial dilution technique was followed and a 103 to 10 8dilution of each sample was prepared. One millilitre of each solution was pipetted onto a Potato Dextrose Agar medium and incubated at 28 °C for 1 week. The culture plates were examined daily and each colony that appeared was considered to be one colony forming unit (cfu). After enumeration of cfu, individual colonies were isolated from the same plates and each uncommon colony was reisolated onto a fresh Potato Dextrose Agar (PDA) plate. Distinct morphological characteristics were observed for identification, and the plates were stored at 4 °C. Two techniques, visual observation on petri dishes and micro-morphological studies in slide culture were adopted for identification of Trichoderma species. For visual observation, the isolates were grown on PDA agar for 3-5 days. The mode of mycelia growth, colour, odour and changes of medium colour for each isolate were examined every day. For studies, a slide culture technique was used. Examination of the shape, size, arrangement and development of conidiophores or phialides provided a tentative identification of Trichoderma spp. Samples were compared to a taxonomic key for the genus Trichoderma spp.