Objective To explore the feasibility of antioxidant enzymes as germplasm evaluation indices of chestnut (Castanea mollissima) and improve the evaluation system of excellent germplasm resources.

Method Eighteen chestnut germplasms were collected in the areas of Yanshan Mountains in Hebei Province. The appearance traits, nutrients and antioxidant components (including 4 enzymatic indexes: superoxide dismutase (SOD), polyphenol oxidase (PPO), peroxidase (POD), catalase (CAT), and 3 non-enzymatic indexes: total polyphenols, total flavonoids and vitamin C) were determined and the qualities of chestnut germplasms were evaluated through subordinate function and factor analysis (with or without antioxidant enzymes) to screen excellent germplasm resources.

Result Among these germplasms, the average weight of single fruit was 9.65 g, the largest was TPZ (12.51 g), and the smallest was QTC (7.88 g); the average water content was 48.85%, the highest was TPZ (51.59%), and the lowest was LJT (45.95%); the average value of starch content was 46.81%, LJT was the highest (53.69%), and JCY-1 was the lowest (38.28%); the average value of soluble sugar content was 7.96%, ZQ1 was the highest (11.62%), and YHZ was the lowest (4.51%); the average value of SOD activity was 1 012.37 U·g⁻¹, the highest was TPZ (1 310.42 U·g⁻¹), and the lowest was ZQ1 (717.40 U·g⁻¹); the average value of POD activity was 4 168.67 U·g⁻¹, JIH was the highest (5 965.33 U·g⁻¹), and JCY-3 was the lowest (3 009.33 U·g⁻¹).

Conclusion Regardless of whether four antioxidant enzymes were used or not in the comprehensive evaluation ranking, the top one was QX107, followed by QL3113, QX3113, and HHZ20. In addition to the above three cultivars, ZJ2 and ZQ1 could be used as candidate elite germplasms for further test. The antioxidant enzymes SOD, POD, CAT and PPO could be considered as the evaluation indices of chestnut germplasms in future.