Fig. 4 Effects of spectrum treatments on growth of (A) shoot length, (B) total length of roots, (C) surface area of roots, (D) volume of roots, (E) root tips, (F) average diameter of roots in nematode-resistant Pinus thunbergii plantlets. Data represent mean ± standard error (SE). Different lowercase letters indicate significant differences between spectrum treatments (p < 0.05, by Duncan’s test). G: Performance of plantlet growth under different light spectrum treatments.