GADKAR, VIJAY, REENA SINGH & ALOK ADHOLEYA.
Microbial Biotechnology, TATA Energy Res Inst, Habitat Place, Lodi Road,New Delhi 110003, INDIA.
VAM fungi are characterized by their inability to grow under pure culture. Of the vast majority of VAM fungi only few are culturable under in vitro conditions by using Ri-T DNA transformed root organ culture (ROC) technique. Using ROC none of the species belonging to the genus Gigaspora has been reported to be subcultured. We report a simple method by which we have been able to continuously culture G.margarita starting from a single spore and have been able to get thousands of viable spores in bigger jar containers.By our method we were able to subculture the progeny spores (starting from a single mother spore) and have been able to get viable spores over more than four generations. Analysis of the progeny spores for polymorphism over four generation on the basis of morphological parameters and DNA fingerprinting using RAPD was done. No variation among the progeny spores of each generation of fungi cultivated under in vitro condition was detected. This technique of culture has proved to be useful for the long term cultivation of this fungi. The lack of observed polymorphism among the generations confirms the genetic stability of these fungi despite the hetrokaryotic nature of the fungus.
Key words: Ri-T DNA, Gigaspora margarita, Subculturing process, RAPD