Effects of volatile organic compounds (VOCs) emitted by three different types of fungi on the root growth of Pinus massoniana. a–f represent the number of root branches and root length of Pinus massoniana exposed to VOCs emitted by symbiotic fungi (Sl, Suillus luteus; Sc, Scleroderma citrinum; Pf, Phialocephala fortinii), a saprophytic fungus (Lp, Lycoperdon perlatum) and a pathogenic fungus (Fo, Fusarium oxysporum), respectively. Due to the fast growth rate of F. oxysporum, only 14 days of P. massoniana root growth data were collected, while the rest of the fungi collected 28 days of data. n = 10. NM, P. massoniana grown in the absence of fungal VOCs. Different letters above bars indicate significant differences between treatments (P < 0.05).