Callus Culture System from Lonicera japonica Thunb Anthers : Light Quality Effects on Callus Quality Evaluation

Abstract Lonicera japonica Thunb has significant edible and medicinal value, offering properties like heat clearing, detoxification, antibacterial, and blood pressure reduction. However, its quality is limited by climate, environment, flowering period, and germplasm degradation. This study established the first embryogenic callus culture system for L. japonica anthers. Using abiotic inducers (light quality), the effects on callus morphology, metabolite accumulation, and antioxidant activity were examined. Results showed that adding 1.0 mg·L− 1 6-BA, 1.5 mg·L− 1 NAA, 1.5 mg·L− 1 2,4-D, and 0.2 mg·L− 1 KT to MS medium induced 81% embryogenic callus. Subculturing with 2.0 mg·L− 1 6-BA, 0.5 mg·L− 1 NAA, and 0.2 mg·L− 1 KT yielded uniform callus lines. SEM and paraffin sectioning distinguished callus types. After 15 days of blue light induction, active metabolites and antioxidant activities peaked. This system supports germplasm innovation and suggests abiotic inducers as a method for higher metabolic product yields.