Study on Life Cycle of Arbuscular Mycorrhizal Fungus Glomus intraradices using In Vitro Culturing Technique

Abstract

In this study, life cycle of arbuscular mycorrhizal fungus, Glomus intraradices isolated from wheat rhizospheres of Damghan region studies using carrot
(Daucus carota L.) transformed hairy roots. Mycorrhizal spores and roots were used as inocula. Spore germination was observed 3-5 days after surface sterilization as well as co inoculation with transformed roots. Fungal growth was also recorded 2-10 days after inoculation. Fungal germinating hyphae branched and produced radical shape network 2.5mm in diameter. The first contact between fungus mycelium and roots occurred 1-3 days after germination. 7 days after fungus- host contact, several secondary spores or vesicle like structures observed which were similar to true spores except of their size (20-30µm diameter). The first true spore formed 25 days after contact and then number of spores increased exponentially. These spores were hyaline and whitish at first but then turned to brownish yellow. After 12 weeks, 1000-2500 spores could be recorded in each plate.