Study of Genetic diversity in Rhizospheric Trichoderma isolates from Uttarakhand

Thirty isolates of Trichoderma obtained from rhizospheric soils of various crops from different locations of Uttarakhand, India were characterized morphologically as Trichoderma harzianum and T. virens. They were compared using RAPD markers to estimate the genetic variations. A total number of 792 reproducible polymorphic bands were obtained using 13 random primers and data were subjected to numerical analysis using NTSYS software and unweighted pair-group (UPGMA) cluster analysis to generate a dendrogram showing the relationship among them. The isolates were grouped into two major clusters; the first major cluster consisted of isolate number PB10, 13, 23, 26, 27 and 28. The remaining isolates in second major cluster were further separated into two sub-clusters; the first sub-cluster consisted of isolates PB5, 15 and 16, and the second sub-cluster consisted of isolates PB 1–4, 6–9, 11, 12, 14, 17–22, 24, 25, 29 and 30. The similarity matrix indicated that isolates PB 8 and 21 were genetically distinct as they showed only 1% similarity followed by PB 11 and 21 (2%) while the isolates PB 29 and 30 were genetically closer, with 61% similarity between them followed by isolate number PB 13 and 14 with 59% similarity.