Soil Nematode Dynamics and Microelement Responses to Talaromyces funiculosus Applications in Bean Cultivation

Abstract

The soil fungus Talaromyces funiculosus plays a crucial role in shaping soil microbial and faunal dynamics, yet its influence on nematode communities and plant nutrition remains poorly understood. This study aimed to evaluate the effects of different concentrations of T. funiculosus aqueous suspensions (20, 40, and 80 cc per pot) on the soil nematode community structure and microelement composition in common bean (Phaseolus vulgaris L.). A control group irrigated with distilled water was included for comparison. Nematode trophic groups were identified microscopically, and diversity indices were calculated using the Shannon–Wiener method. In addition, the concentrations of Fe, Zn, Mn, and Cu in leaves and whole plant tissues were determined by atomic absorption spectrophotometry (AAS). The results demonstrated that T. funiculosus applications markedly altered nematode community structure. Total nematode abundance increased up to sevenfold compared to the control, primarily due to significant rises in bacterivore and fungivore groups, indicating a strong stimulation of the microbial energy channel. However, plant-parasitic nematodes also increased in certain replicates, suggesting variable effects on plant health depending on dosage and soil conditions. Shannon diversity indices ranged between 0.56 and 1.15, reflecting heterogeneous community responses. Microelement analyses revealed that T. funiculosus treatments affected nutrient uptake, particularly decreasing Fe and Cu concentrations in plant tissues, while Mn and Zn levels remained relatively stable. These results indicate that T. funiculosus can substantially influence soil biological structure and plant mineral composition, emphasizing the need for careful optimization of its application levels in sustainable bean cultivation.