Seed germination behaviour and dormancy of Martynia annua: First confirmed report of physiological dormancy in martyniaceae

Despite its medicinal value and invasive nature, the ecophysiology of seed germination in Martynia annua remains poorly understood. Thus, a study was conducted to explore the seed germination behaviour of this species. Diaspores were collected from the dry zone of Sri Lanka and brought to the University of Peradeniya, Sri Lanka. Seed moisture content and seed coat: seed mass ratio were determined. Imbibition and germination of fresh seeds were evaluated. The effect of dry storage and gibberellic acid (GA₃) on germination was tested. Seeds with and without woody endocarp imbibe water readily and their seed mass increased to 61 and 104% within 10 days of imbibition. Water-permeable seeds with fully developed embryos suggest that germination of M. annua seeds was not affected by the presence of the woody endocarp, indicating the absence of physical, morphological and morphophysiological dormancy in its seeds. However, seeds with and without endocarp failed to germinate under control (distilled water) treatment, whereas 500 ppm GA3 treated seeds germinated >90% both with and without endocarp. Removal of endocarp considerably enhanced germination speed as GA3-treated seeds completed germination within 11 days, while GA3-treated seeds with intact endocarp took 1 month. Dry-stored seeds retained >90% viability even after 12 months of storage. These results confirm that M. annua produces desiccation-tolerant seeds with physiological dormancy, enabling long-distance dispersal across both spatial and temporal scales. This trait likely contributes to the species’ successful distribution and invasion.