Arbuscular Mycorrhizal Fungi (AMF) can form symbiotic relationship with rice, preferably in the modern rice production systems such as System of Rice Intensification (SRI), aerobic and upland conditions. Their association with rice roots under in vitro conditions was investigated in this study. A suspension containing one lakh (1, 00,000) spores of Rhizophagus irregularis was employed to standardize optimum AMF spore load/seedling and evaluate its effect on Root System Architecture (RSA). The results indicated that different spore loads of AMF inoculated with rice seedlings, under in vitro conditions, modified most of the traits of RSA of rice at early stages significantly better than the uninoculated Control. The in vitro study clearly showed that the seedlings of rice with AMF inoculated with a dose of 14 µl/seedling (31 spores/ seedling) recorded maximum root colonization of 100 per cent by AMF in rice.
Key words : AM Fungi, Spore load, Rice (Oryza sativa), RSA, in vitro, Principal Component Analysis (PCA).