Germination and abscisic acid analysis in the seeds of forest resource trees after storage at different temperatures

Abscisic acid (ABA) is a plant hormone that plays a significant role in various developmental and physiological processes in higher plants. In this study, ABA was quantified in Chamaecyparis obtusa, Pinus rigida × Pinus taeda, and Pinus densiflora seeds stored for 20 years at −18 °C, 4 °C, or 25 °C using high-performance liquid chromatography. At all temperatures, C. obtusa had the highest ABA concentration, followed by P. rigida × P. taeda and then P. densiflora. The germination rates of the seeds were also investigated. For the two Pinus species, there was an inverse relationship between ABA content and germination rate. However, as all C. obtusa seeds failed to germinate, no such correlation was observed for this species. This study provides important information for advancing ABA research in gymnosperms, which may provide insight into their physiological and biochemical mechanisms.