Fig. 19. Light micrograph of peach tissues inoculated with L. persoonii. Longitudinal section through a portion of colonized bark showing relative position of polysaccharide-rich zone (AYZ), ligno-suberized tissue (IT), and newly generated phellogen (PG). Note hyphae (arrow) and small callus lip (C). x560. (From Biggs, 1984).