Seed recalcitrance of Careya arborea- A medicinal plant from a dry deciduous forest

Careya arborea is an important medicinal plant, and the storage behavior of the seeds of this species is not well-studied. The objective of this investigation is to test the recalcitrant nature of the seeds of C. arborea. The developmental changes, desiccation sensitivity, and storage capability of the seeds were studied. Seeds were harvested at different maturation stages and fresh weight, dry weight, moisture content, germination percentage, and desiccation tolerance were evaluated. Desiccation sensitivity was determined by recording germination after drying the fresh seeds. Seeds were stored at different conditions and viability was assessed at intervals. During its development, full germinability of seed was achieved long before mass maturation, and seeds were found to be desiccation-sensitive at all stages of development. Maximum drying tolerance was observed 7–10 days after mass maturity when the color of the seed was greenish-brown, which can be considered an indicator of the best time for seed collection. The lowest safe moisture content of mature seeds was 25–30%. Among different storage conditions, storage at 28–30°C at shedding moisture content (39-42%) could best retain viability for 120 and 150 days for ungerminated seeds and sprouts, respectively. Seeds cannot be stored at low temperatures (even at 15°C) which indicates their highly recalcitrant nature.