Optimizing of carrot hairy root induction and stabilization for monoxenic culture of arbuscular mycorrhizal fungi

This study was conducted to optimizing of in vitro culture of Arbuscular Mycorrhizal Fungi (AMF) on in vitro root and petiole and greenhouse petiole and stem of carrot. Carrot seeds were disinfested and cultured on MS medium and pot. Four weeks old of in vitro root and petiole and 3 months old of greenhouse petiole and stem were inoculated with Rhizobium rhizogenes MSU, 15834 and A4 strains and cultured on MS medium. The effects of bacterial strain and explants type on hairy root production were studied. After the elimination of bacteria, growth rate of hairy roots obtained from each explants were measured in factorial experiment with completely randomized design with three replications and three explants in each replicate. Molecular confirmation of hairy roots induction and bacterial strains were performed using specific amplification of rolC gene in PCR reactions. The results showed that all bacterial strains could initiate hairy root production. Transgenic roots were thicker, more branches and higher growth rate compared to normal roots. 15834 bacterial strain and greenhouse petiole and in vitro root explants demonstrate the highest ability in hairy root production. The highest growth of hairy roots were observed in greenhouse stem explant with MSU bacterial strain.