Effects of the Fungal Endophyte Paecilomyces Lilacinus in Cotton On the Root-Knot Nematode Meloidogyne Incognita

Some populations of the fungus Paecilomyces lilacinus are parasitic on eggs of the root-knot nematode Meloidogyne incognita.  Further, cotton in Texas recently was found to harbor P. lilacinus as a naturally-occurring endophyte. Greenhouse experiments were conducted to test for an effect of endophytic P. lilacinus in cotton on reproduction of the root-knot nematode. Seeds were planted after treatment with two different concentrations of P. lilacinus conidia solutions, and young seedlings were transferred to sandy soil at the first true-leaf stage. Plants were harvested seven weeks after inoculation with 10,000 nematode eggs/plant. Significant decreases in egg masses and total number of eggs per plant were found among plants treated as seeds with a higher concentration of fungal conidia solution, compared to untreated plants. However, no significant difference was found between untreated plants and plants treated with a lower concentration of endophyte conidia solution. These data suggest that the endophytic association of P. lilacinus with cotton may affect the relationship between cotton and the nematode parasite.