Variation in rDNA ITS sequences in Glomus mosseae and Gigaspora margarita spores from a permanent pasture

To study the genetic variability in Glomas mosseae and Gignaspora margarita sequence similarities of ITS regions of rDNA were analysed from spores col lected from a permanent pasture and from pot cultures. PCR amplification wi th the primers ITS1 and ITS4 was performed and produces were cloned and seq uenced. The sequences from single spores of G. mosseae and Gi. margarita co nfirmed that there is variation in the ITS region in a single spore. Phenet ic analysis of sequences from both species supported the morphological iden tification which placed the species into two separate groups. Through the a nalysis of these sequences an estimate of genetic diversity was derived whi ch clearly showed that the three field spores of G. mosseae were at least 2 -5 times more genetically diverse than one single spore (field) and a pool of spores (pot culture) of Gigaspora margarita. This demonstrates that a hi gh degree of variation exists in this natural population of G. mosseae.