Evaluation of the combined application of Purpureocillium lilacinum PLSAU-1 and Glomus sp. against Meloidogyne incognita: implications for arsenic phytotoxicity on eggplant

Abstract

Glasshouse pot experiments were conducted to evaluate the efficacy of Purpureocillium lilacinum PLSAU-1 (Pl) either alone or in combination with Glomus sp. (G) to control southern root-knot nematode, Meloidogyne incognita (Mi) in Solanum melongena in arsenic (AS)-contaminated soil. Root fragments of maize seedlings were applied to 5 g roots containing approximately 200 G colonized root fragments/100 g potting soil and G colonized 100 g rhizosphere soil of maize containing 30 chlamydospores/g soil and thoroughly mixed with sterilized potting soil for the G treatment. Pl was applied to the potting soil at 5 × 106colony-forming units (CFU/g soil). AS solution was added to the potting soil at 50 mg kg−1. Sixteen treatments comprising single and combined applications of Pl, G, AS, and Mi with five replications were applied and pots were randomly arranged in the glasshouse. Single nematode-free eggplant seedlings (30-days old) were transplanted. Eggs of Mi were inoculated at 10000 eggs/seedling pot. Data were recorded on root gall index, plant growth parameters, N, P, K and S uptake, and AS uptake 2 months after transplantation. The combined application of Pl and G enhanced plant growth, leaf area, chlorophyll content, nutrients uptake and reduced AS toxicity. Gall index and AS uptake were reduced by 84.50% and 51.72%, respectively with the combined application of Pl and G. We conclude that Pl and G can be integrated as biological management tools against Mi in AS polluted vegetable growing areas.