Mycorrhizal syntheses between Lactarius spp. section Deliciosi and Pinus spp. and the effects of grazing insects in Yunnan, China.

Ectomycorrhizal fungi (EMF) in Lactarius sect. Deliciosi produce valuable edible mushrooms. Market supplies are harvested from natural populations. Sustainable cultivation could increase commercial crop production. The first step in EMF cultivation is the production of host seedlings well colonised by the target species. The aim of this study was to compare the efficiency of vegetative versus spore inoculum for controlled mycorrhizal synthesis between Lactarius and Pinus species native to China. Inoculated seedlings were incubated in a glasshouse for up to 14 months. Mycorrhizae were synthesised, using vegetative inoculum, for 13 distinct combinations of five Pinus and five Lactarius species, 12 of these unprecedented. Spore inoculation was not successful. The successful mycorrhization presented here provides a foundation for establishing mushroom orchards, with L. deliciosus × P. yunnanensis or P. radiata, L. hatsudake × P. yunnanensis or P. tabuliformis, and L. vividus × P. massoniana or P. radiata appearing as promising symbionts for cultivation. Beginning 5 months following inoculation, mycorrhizal seedlings underwent extensive insect grazing. Adult forms of Bradysia impatiens were the most frequent insects caught on sticky traps, while their larvae were observed foraging through roots. The control of insects in the nursery will be critical to large-scale production of mycorrhizal seedlings. [ABSTRACT FROM AUTHOR]