Abstract: [Objective] The quality of Ginkgo(Ginkgo biloba) kernel from different agroforestry systems was studied to explore variations of seed yield and properties, kernel nutrients and secondary metabolites among different agroforestry systems,in order to provide a reference for application of different agroforestry systems in Ginkgo trees for nut production. [Method] Five traditional Ginkgo agroforestry systems (Ginkgo-Cole (Brassica campestris)-Peanut (Arachis hypogaea), Ginkgo-Wheat (Triticum aestivum)-Peanut, Ginkgo-Broadbean (Vicia faba)-Peanut, Ginkgo-Mulberry (Morus alba), Ginkgo-Cole-Corn (Zea mays)) and a control system (the pure Ginkgo stand) were chosen, and seed yield and mass, nut mass, kernel mass, and content of starch, protein, fat, soluble sugar, total flavonoids, terpene lactones, ginkgoic acid, HCN were measured to evaluate the quality of Ginkgo kernels using an improved analytic hierarchy process. [Result] Significant differences were observed in Ginkgo seed yield, nut mass, and contents of starch, protein, soluble sugar, total flavonoids, terpene lactones, ginkgoic acid, HCN among different systems (P<0.05). The Ginkgo seed yield, nut mass, contents of protein and soluble sugar were higher in the agroforestry systems than in the pure Ginkgo stand. The highest Ginkgo seed yield was found in Ginkgo-Mulberry system with 31.07 kg per tree, and Ginkgo-Broadbean-Peanut system had the highest nut mass, and contents of protein and soluble sugar, reaching 2.34 g, 101.73 mg·g^-1, 88.11 mg·g^-1, respectively. Higher contents of starch (0.55 g·g^-1), total flavonoids (2.69 mg·g^-1), terpene lactones (7.32 mg·g^-1), ginkgoic acid (47.54 μg·g^-1), HCN (0.44 μg·g^-1) were found in the pure Ginkgo stand than in Ginkgo agroforestry systems. The lowest total flavonoids, ginkgoic acid, and HCN were found in Ginkgo-Cole-Peanut system, only reaching 1.84 mg·g^-1, 28.52 μg·g^-1and 0.27 μg·g^-1, respectively, and the lowest content of terpene lactones was found in Ginkgo-Broadbean-Peanut system with a value of 4.82 mg·g^-1. The improved analytic hierarchy process showed that the content of HCN was the most impacting factor for Ginkgo kernel quality, and its weight reached 0.210 3, followed by protein, soluble sugar, total flavonoids, ginkgoic acid, kernel mass, starch, terpene lactones, seed mass, and nut mass. Further calculation of Ginkgo kernel quality indicator showed that Ginkgo agroforestry systems had better Ginkgo kernel quality indicator than pure Ginkgo stand, and Ginkgo kernel quality in Ginkgo-Broadbean-Peanut system was the best with 0.414 8, followed by Ginkgo-Wheat-Peanut, Ginkgo-Mulberry, Ginkgo-Cole-Peanut, and Ginkgo-Cole-Corn.[Conclusion] The quality of Ginkgo kernel was improved in agroforestry system; it can be applied in Ginkgo trees for nut production, especially in Ginkgo-Broadbean-Peanut system which is suitable for promotion and application.

Key words: Ginkgo biloba, Ginkgo trees for nut production, agroforestry system, Ginkgo kernel quality, analytic hierarchy process