Arbuscular mycorrhizal fungi as a promising biomaterial for controlling root rot of Panax notoginseng

Abstract

Root rot is a main disease in Panax notoginseng, which is severe and difficult to control. Arbuscular mycorrhizal fungi (AMF) are known to effectively prevent plant diseases caused by soil-borne pathogens. However, the potential role of AMF as a biocontrol agent against root rot in P. notoginseng is still unclear. This study aims to investigate the efficacy of AMF, including Funneliformis mosseae, Rhizophagus intraradices and Claroideoglomus etunicatum, individually and in combination, for controlling root rot in P. notoginseng seedlings. The effect of different AMF on the indicators of P. notoginseng growth, superoxide dismutase, peroxidase activity, proline, malondialdehyde, soluble sugars and proteins were measured. The effects of different AMF on root rot resistance were comprehensively evaluated using the subordinate function method. The results showed that the incidence of root rot decreased from 75% to 12.5%–50.0% after inoculation with different AMF agents, and the disease index decreased from 22.92% to 6.25%–16.67%. Moreover, AMF significantly increased the growth parameters of P. notoginseng, such as plant height (6.35%–41.73%), stem diameter (12.98%–45.96%), fresh weight (6.28%–95.35%), and leaf area (8.89%–97.71%). Moreover, AMF also improved the content of chlorophyll (2.40%–50.67%) and rate of net photosynthetic (52.08%– 279.17%), enhancing superoxide dismutase (4.02%–114.89%) and peroxidase activity (85.60%–139.98%), as well as promoting the accumulation of soluble sugars (30.21%–90.00%), proteins (3.31%–65.81%), and proline (4.02%–114.89%) in the root and leaf, while reducing the malondialdehyde content (19.99%–139.98%). Particularly, C. etunicatum was found to be the most effective in promoting growth and disease resistance in P. notoginseng. These findings provide insights into the potential use of AMF as an effective biocontrol agent to manage root rot.