Abstract Arbuscular mycorrhizal (AM) fungi display a wide range of life history strategies, yet these strategies remain insufficiently characterized in several Glomeromycota lineages, particularly within the understudied Entrophosporaceae. Elucidating this variation is important for understanding the influence of AM fungal diversity on symbiotic function and plant performance. This study quantified temporal patterns of sporulation, root colonization, extraradical hyphal production, and plant growth responses for 13 fungal isolates representing Entrophosporaceae, Acaulosporaceae, Gigasporaceae, and Glomeraceae. We predicted that (i) Entrophosporaceae would exhibit trait conservatism and (ii) traits of Entrophosporaceae is relatively more similar to Glomeraceae than to the other AM fungal families, considering their closer phylogenetic relationship. Sorghum bicolor was cultivated in compartmented pots equipped with 45-µm mesh bags and inoculated with individual fungal isolates; plants were harvested at 21, 28, 42, 56, and 84 days after germination. Significant differences among fungal isolates were observed in sporulation, root colonization, extraradical hyphal length, and effects on shoot biomass, with these responses varying over time. All Entrophosporaceae isolates significantly increased host shoot biomass relative to the non-mycorrhizal control but showed increased sporulation over time and contrasting colonization dynamics. We observed rapid early colonization followed by decline at 84 days or bell-shaped temporal patterns. In contrast, extraradical hyphal length in Entrophosporaceae remained relatively stable throughout the experiment. Host shoot biomass was positively correlated with both root colonization and extraradical hyphal length, but not with arbuscule abundance. Root colonization and extraradical hyphal length over time in Entrophosporaceae were comparable to those in Acaulosporaceae, Glomeraceae, and Gigasporaceae. Collectively, these findings demonstrate that Entrophosporaceae encompasses substantial functional diversity, including both ruderal, competitive, and stress-tolerant strategies. Evaluating temporal dynamics using trait-based approaches is important for resolving AM fungal life history variation and predicting contributions to plant growth.
Laurindo et al. (Sat,) studied this question.