Plant growth-promoting ability and control efficacy of Penicillium aurantiogriseum 44M-3 against sesame Fusarium wilt disease

Penicillium sp. 44M-3, previously isolated from soil samples in Sanmenxia City (Henan Province, China), was identified as Penicillium aurantiogriseum Dierckx based on sequence analysis of ITS-rDNA, beta-tubulin, and calmodulin. In co-culture assays against 14 pathogenic fungi, the inhibition ratios achieved by isolate 44M-3 ranged from 42.90% to 66.0%. Optimising the culture medium conditions to maximise the production of inhibitory substances increased the average inhibitory activity of the filtrate by 44.25% compared to that of the original culture filtrate. Isolate 44M-3 secreted extracellular enzymes such as protease, cellulase, and beta-1,3-glucanase on agar plates. Treatment with a spore suspension of isolate 44M-3 significantly reduced the incidence of Sesame Fusarium wilt (P = 0.036) in pot experiments, achieving a maximum control efficacy of 75.88%, which did not differ significantly from carbendazim treatment (P = 0.292). Treatment with isolate 44M-3 spore suspension increased the root length of wheat and dry weight of whole sesame, maize, and tobacco plants, likely due to the isolate's ability to dissolve insoluble inorganic phosphorus and secrete siderophores and indole acetic acid. Consequently, isolate 44M-3 provides a promising candidate for plant growth promotion and prevention of sesame Fusarium wilt disease.