Potencial biocontrolador de Purpureocillium lilacinum contra Meloidogyne incognita en condiciones controladas
Abstract
Meloidogyne incognita is one of the most economically important plant-parasitic nematodes, causing substantial yield losses in horticultural crops worldwide. The increasing restrictions on chemical nematicides have intensified the search for sustainable biological control alternatives. This study evaluated the biocontrol potential of three Purpureocillium lilacinum isolates (CEP1, CEP2, and CEP3) against M. incognita in tomato plants under controlled conditions. The number of root galls, second-stage juvenile (J2) density per gram of soil, fungal colonization of the root system and soil, and fresh and dry root biomass were assessed. Pearson correlation analysis and principal component analysis (PCA) were performed to investigate the relationships among nematological, microbiological, and agronomic variables. All P. lilacinum isolates significantly suppressed nematode development compared with the infested control. Isolate CEP1 exhibited the highest biocontrol efficacy, reducing root gall formation by 93.9% and J2 density by 89.8%. CEP1 also achieved the greatest root colonization (70.7%) and soil colonization (33.3), which was associated with increased fresh (7.3 g plant⁻¹) and dry (1.10 g plant⁻¹) root biomass. Correlation analysis revealed a positive association between root gall formation and J2 density (r = 0.68), whereas both variables were negatively correlated with fungal colonization and root biomass. PCA explained 91.9% of the total data variability and clearly separated the infested control from the fungal treatments, highlighting the close association between P. lilacinum establishment, nematode suppression, and improved root development. These findings demonstrate that P. lilacinum, particularly isolate CEP1, is a promising biological control agent for the sustainable management of M. incognita in tomato production systems and supports its integration into environmentally friendly nematode management strategies