GENERATION OF RAPD-PCR PRIMERS FOR THE IDENTIFICATION OF ISOLATES OF GLOMUS-MOSSEAE, AN ARBUSCULAR MYCORRHIZAL FUNGUS

Mycorrhizal fungi are usually identified on the basis of the morpholog ical characters shown by fruit bodies, spores, vegetative mycelia or s ymbiotic structures. The development of molecular techniques provides a valuable and alternative approach to identify mycorrhizal fungi, esp ecially when it is difficult to gather a sufficient number of data on morphological features. Short arbitrary oligonucleotides were used as primers for the amplification of genomic DNA extracted from spores of arbuscular fungi. The RAPD fingerprints showed banding patterns which allowed us to distinguish between species and even isolates within Glo males. In order to identify mycorrhizal fungi during their symbiotic p hase, a nonpolymorphic RAPD band identified as marker for some isolate s of Glomus mosseae was purified from agarose gels and cloned in a blu escript vector. The fragment was sequenced and specific primers (PO-M3 ) were designed for the mycorrhizal fungus. They specifically and succ essfully amplified the DNA not only from G. mosseae spores, but also f rom roots of pea, clover, leek and onion plants when they were coloniz ed by G. mosseae isolates.