highly significantP < 0.0001
By applying Design Expert 8.0.7.1 to fit a multiple regression to the data, the quadratic equation of Schisandra chinensis AC yield (Y) to each factor variable can be obtained as: (1) Y = 1.11 + 0.14 A + 8.3 × 10 - 3 B + 0.14 C + 0.067 A B + 0.098 A C + 0.15 B C - 0.21 A 2 - 0.16 B 2 - 0.29 C 2 The results of the regression model analysis shown in Table 7 indicate that this quadratic multinomial regression model had highly significant differences ( P < 0.0001), indicating a highly significant correlation between the three independent variables involved and the response values of AC.