Inoculation of Pinus pinea seedlings with Pisolithus tinctorius and Suillus bellinii promotes plant growth in benfluralin contaminated soil

Abstract

In order to develop new strategies aiming at reconverting agriculture-managed soils into forest plantations, pesticides effect on plant growth needs to be further understood. Thus, the development of Pinus pinea seedlings on soil spiked with benfluralin mimicking different application rates was evaluated, as a well as its effect on root colonisation with Pisolithus tinctorius and Suillus bellinii. P. pinea development and ectomycorrhiza colonization on soil spiked with benfluralin were assessed after 6 month growth. P. pinea seedlings inoculated with P. tinctorius showed higher plant growth and increased nutrient levels than seedlings inoculated with S. bellinii. At field application rate, benfluralin had an inhibitory effect on growth of non inoculated plants. Inoculation with P. tinctorius promoted plant development and nutrient uptake whereas inoculation with S. bellinii did not seem to confer plant protection against the toxic. Although P. tinctorius and S. bellinii were able to form ectomycorrhizae in the presence of benfluralin, the extent of root colonisation was affected by the herbicide. P. tinctorius conferred protection to P. pinea against benfluralin toxicity, overcoming the effect of the herbicide on P. pinea growth and nutrient uptake. This approach can be advantageous for plant establishment on pesticide contaminated soils.