Water loss and response to desiccation of Castanopsis sclerophylla (Fagaceae) seeds

In many -but not all- recalcitrant Quercus seeds, water loss during drying only occurs through scar. Consequently, embryo sitting on the opposite side of scar is well protected from desiccation. However, whether such mechanism is common throughout Fagaceae species is unexplored. Similarly, little is known about the desiccation response of other Fagaceae genera. Germination and desiccation tolerance of Castanopsis sclerophylla (Fagaceae) were studied by drying the seeds. Fresh seeds had a moisture content (MC) of 36% and germinated to 93% when incubated at 15/20°C. Drying seeds to 22.5 and 20.7% MC decreased germination to 27 and 0%, respectively; indicating seeds are recalcitrant. X-ray computed tomography and photomicrographs showed that embryo of C. sclerophylla sits just below scar. Regardless of drying occurring either through only scar or whole pericarp, embryo drying was deemed unavoidable. Nevertheless, germination percentage during drying showed exceptional similarities with the other Fagaceae species.