Spore multiplication and infectivity of arbuscular mycorrhizal fungi

Spores are reproductive structures produced by arbuscular mycorrhiza fungi (AMF) and they multiply in the soil, enhancing their potential for infection. This study aimed to evaluate spore multiplication (SM) and the infectivity percentage (IP) of AMF. A maize rhizosphere soil was identified as an AMF niche and verified through spore extraction and microscopic observations. A portion of 200g of AMF spore-enriched soil (AMFSS) was combined with full and half rates of chemical fertilizers (CF) and compost for the treatments, using mung bean as the host plant. A pot experiment was conducted under controlled conditions, arranged in a Completely Randomized Design (CRD) with three replicates for each treatment. The sterilized soils (SS) were added to the pots before the application of treatments. Treatments were T1 (SS + AMFSS), T2 (SS + 100% compost + AMFSS), T3 (SS+ 100% CF+ AMFSS), and T4 (SS + 50% CF + 50% compost+ AMFSS). Spore count (SC) per 1g of soil and root infectivity percentage (IP) were assessed at two week intervals up to two months. All the data were statistically analyzed using analysis of variance (ANOVA), and means were separated using LSD test. Results revealed that the significantly highest cumulative SC (49 spores/g ± 2.5) and the root IP (61.67% ± 1.43) were recorded in the SS + 100% compost and AMFSS mixed treatment (T2) over time.  Accordingly, this study concludes the higher spore multiplication and infectivity of AMF with compost compared to chemical fertilizers. Therefore, these AMF spores demonstrate promising potential for use as inoculum in biofertilizer production.