Multiple shoots of Carapa surinamensis seeds: Characterization and consequences in light of post-germination manipulation by rodents

Post-germination manipulation of seeds by rodents arrests shoot development, yet seed tissues may remain alive becoming an important food supply over several months. Seeds of Carapa surinamensis show polyembryony in the Central Amazon, which could counter predatory seed manipulation. To test this concept, we characterized the polyembryony of C. surinamensis seeds by assessing the number of shoots per seed over time and with respect to seed mass. We also simulated rodent manipulation over two post-germination stages, comparing re-sprouting of C. surinamensis with Carapa guianensis, the latter usually producing only one shoot. Metabolic activity of the seed reserves was tested by tetrazolium staining. We found multiple shoots in over 50% of C. surinamensis seeds and up to five shoots per seed; however, the number of shoots was not related to seed mass. The interval between successive shoot production by the same seed was up to 46 days. Some re-sprouting occurred after radicle pruning (45% of C. surinamensis and 57% of C. guianensis seeds). The removal of two meristems resulted in “zombie seeds” (76% in C. surinamensis and 81% in C. guianensis). Polyembryony did not provide an advantage in re-sprouting in comparison to monoembryonic seeds. Seed manipulation maintained the viability of seed reserves under moist and hot (25 °C) conditions for 6 months.