Figure 4.

Changes of cell wall degrading enzymes activity in the ‘Ruixue’ and ‘Ruixianghong’ varieties and their parents apples during fruit development and ripening. (A) Polygalacturonase (PG), (B) β-galactosidase (β-gal), and (C) cellulase (CEL). Data are presented as means from three independent experiments; the vertical bars indicate the standard error of the mean. Different lowercase letters in columns denote significant differences between sampling dates for each cultivar by Duncan’s multiple range test (p < 0.05). Different capital letters in columns denote significant differences by Duncan’s multiple range test (p < 0.05) among different cultivars. Different colors represent different periods.