Abstract: To establish an accurate, rapid, and non-destructive leaf area estimation model for Atractylodes macrocephala, the allometric growth method was used to determine the leaf area coefficient (K) of different leaf shapes of undivided leaves of Atractylodes macrocephala. Linear regression analysis was conducted to analyze the observed leaf area (OLA) and predicted leaf area (PLA) of undivided leaves and pinnately compound leaves, so as to verify the applicability and accuracy of K. The results showed that the K values of six types of undivided leaves (ovate, broadly elliptical, elliptical, oblong-ovate, oblanceolate, and long elliptical) were 0.681, 0.646, 0.631, 0.616, 0.619, and 0.616, respectively. There was no significant difference between the average K of all leaves and the K values of elliptical, oblanceolate, oblong-ovate, and long elliptical leaves, so it was determined as the universal leaf area coefficient of Atractylodes macrocephala (0.625). Linear regression analysis of OLA and PLA for the six types of undivided leaves showed that PLA was highly fitted with OLA for each leaf shape, and all correlations reached an extremely significant level. Linear regression analysis of pinnately compound leaves showed that there was also an extremely significant correlation between OLA and PLA (R²=0.952), and the difference between the two conformed to a normal distribution, indicating that K=0.625 was also applicable to the leaf area estimation of pinnately compound leaves. Finally, the leaf area coefficient of Atractylodes macrocephala was determined to be 0.625, and the established estimation model was PLA=0.625×L×W (R²=0.989) (L: leaf length, W: leaf width).

Key words: Atractylodes macrocephala Koidz., leaf morphology, leaf area coefficient, allometric growth method, estimation model