Improved parameters of Pinus greggii seedling growth and health after inoculation with ectomycorrhizal fungi

Pinus greggii Engelm. ex Parl. is an endemic pine of Mexico with notorious adaptability to eroded, shallow and poor soils. It is widely used in reforestation programmes worldwide. The purpose of the present study is to develop an ectomycorrhizal fungi (ECM) treatment with different native ectomycorrhizal fungal species (collected in P. greggii and Abies vejarii stands) to improve seedling survival of P. greggii. Four-month-old P. greggii var. greggii seedlings were inoculated with ground fruiting bodies of the ECM species Astraeus spp., Boletus barrowsii, Geastrum minimum, Lactarius deliciosus var. deterrimus, Russula cf. atroglauca, Russula spp., Suillus caerulescens, as well as a mixture of three species (Russula sp., R. lutea and L. deliciosus) and soil litter with mycelium from the base of a fruiting body of L. deliciosus. Agronomic variables, and total phosphorous and glucosamine contents were measured in P. greggii seedlings. Inoculated treatments with B. barrowsii, Geastrum minimum and S. caerulescens showed increases in seedling height and basal diameter as well as dry shoot biomass compared with those of the control plants. Geastrum minimum, B. barrowsii and R. xerampelina significantly increased values of dry weight compared with that of the control. Inoculation of soil litter from the base of a fruiting body of L. deliciosus induced the maximum glucosamine response (40.2 mg g⁻¹ of dry root biomass). Geastrum minimum, a fungus collected in P. greggii stands, enhanced basal diameter of pine seedlings in the nursery. Fungal species B. barrowsii, Suillus caerulescens, Russula cf. atroglauca and Russula spp. from the Abies forest improved plant quality in terms of the Dickson quality index and root and shoot biomass, compared with those of the control.