Modified Strullu and Romand (MSR) medium devoid of sucrose promotes higher in vitro germination in Rhizophagus irregularis

Abstract

Arbuscular mycorrhizal fungi (AMF) are obligate symbionts belonging to the phylum Glomeromycota (Schuler et al 2001), that cannot complete their life cycles without establishing a functional symbiosis with a host plant. Spore germination ability has considerable impact on different host plant species (Pawlowska et al 1999) and capacity of the fungi to complete its life cycle relies on the production of adequate spores. Though the potential of AMF's plant growth promotion and biocontrol efficacy is well recognized, culturing and mass multiplication still remain a constraint in their popularization. A primary pre-requisite for germination of AM propagules (spores and root fragments) is hydrometabolism activation (Dalpe et al 2005). The time required for spore germination of different genera may range from 2 to 90 d. Attempts to determine requirements for spore germination and germ tube growth on artificial media have met with variable success, probably due to variation in methodology, fungal species and the culture conditions employed.