Seed priming increases the vigor of seeds and seedlings through metabolic and biochemical processes occurring during controlled hydration, followed by dehydration. In the field, seeds are exposed to hydration-dehydration events in and on the soil after dispersal, as in seed priming. Nevertheless, seed priming has been sparsely tested on desiccation-sensitive seeds, which are vulnerable to climate change effects. We evaluated the effect of two priming methods on seeds from two tropical rainforest species: Cupania glabra and Cymbopetalum baillonii. For hydropriming, the seeds were fully hydrated and then dehydrated to three dehydration levels. For natural priming, the seeds were buried for 12 days in either closed forest or forest gap. Primed seeds were sown in 1% agar medium and placed in an environmental chamber. The growth of the seedlings from the highest germination priming treatments was evaluated for 1 year in the field. Our results showed that for C. glabra and C. baillonii, hydroprimed seeds varied in their germination response, depending on the degree of their dehydration. However, for C. baillonii, hydropriming seems to invigorate seeds, compared to non-imbibed seeds of the same dehydration level. Natural priming increased germination speed in both species without any difference between closed forest and forest gap. Moreover, seeds with natural priming had a higher final germination percentage than seeds with hydropriming. Seedlings from seeds with natural priming showed a higher growth rate than the controls in both species, whereas hydropriming produced a similar effect in C. glabra. Both priming methods could be used for restoration practices with the studied species, natural priming being a novel method. The ecological implications of priming in desiccation sensitive seeds are discussed in this study.

To design conservation strategies, the extent of plant richness of tropical forests needs to be characterized in terms of their seed longevity. In this study, we examined the potential seed longevity, that is, storage ex situ, of species from southeastern Mexico: Chamaedorea glaucifolia, Cymbopetalum baillonii, Magnolia mexicana, Nectandra coriacea, and Ternstroemia tepezapote. Immediately after collection, seeds were stored at different temperatures (23 C). We evaluated seed germination after different storage durations. Seed water content (WC) was determined for each period. Seed desiccation sensitivity was determined as WC 50 , which is the WC at which the initial seed viability decreases to 50%; further, the time required to reach WC 50 was also determined. Subsequently, we analyzed the relations between seed functional traits with other morphological and functional traits, along with the weather characteristics of their respective habitat. All of the studied species had shortlived seeds; they exhibited desiccation sensitivity after storage with differences across the species. Additionally, C. baillonii exhibited differences in seed desiccation sensitivity across 2 years of seed collection. Interaction was observed between storage time and storage temperature: Seeds exhibited less deterioration at 15 C in C. glaucifolia and C. baillonii and at 5 C in M. mexicana and N. coriacea. Seed storage behavior is discussed in this article. Finally, a relationship determined between germination traits, and seed WC, embryo size, endosperm amount, and rain and temperature patterns in the month of seed dispersal explained the limited longevity of the studied species.