Germination of palm seeds under periods of rehydration

Abstract

Palm seeds are indicative of being recalcitrant species. Seeds germination for many species, is slow and uneven, even in favorable conditions, often due to the resistance of the woody endocarp that makes them impermeable to water. Most species also have the characteristic of not tolerating the drying process at low moisture levels, thus losing their viability. In view of these considerations, the objective was to evaluate the effect of different periods of rehydration on the germinative process of seeds of royal palm, dwarf palm and jeriva. Seeds were homogenized and immersed in water containing 3 times their volume, with daily replacement. The experimental design used was completely randomized, with 5 treatments (0, 3, 6, 9, and 12 days of rehydration), with 4 replications of 25 seeds. The seeds were placed in transparent “gerbox” plastic boxes containing medium vermiculite as substrate and placed in BOD with a photoperiod of 16-hour of light and their respective optimum temperatures for each species. The number of germinated seeds was counted every 2 days until germination stabilized. The variables analyzed were germination percentage, germination speed index (GSI), average germination time (AGT) and distribution of germination over the days. Rehydration for 3 days increased the germination rate of royal palm seeds. For dwarf and jeriva species, rehydration did not influence the analyzed variables. The GSI and AGT were negatively influenced by the rehydration periods for royal palm. Rehydration prolonged the peak of germination of the studied species.

Water immersion and one-year storage influence the germination of the pyrenes of Copernicia alba Morong, a palm tree from a neotropical wetland

“…Palm seeds often display morphophysiological dormancy due to underdeveloped embryos (Baskin & Baskin 2014) and a thick endocarp that delays germination and embryo growth (Pérez 2009, Ribeiro et al 2011, Oliveira et al 2013, Carvalho et al 2015, Oliveira et al 2015, Soares et al 2021. Water treatments may accelerate the germination process of palm seeds by facilitating oxygen absorption and loosening mechanical restrictions of the surrounding tissues (e.g., Bovi 1990, Martin et al 1996, Ferreira & Gentil 2006, Fava & Albuquerque 2011, Rubio Neto et al 2012, Pinto et al 2012, Goudel et al 2013, Ferreira et al 2021. On the other hand, hot-water treatments (~75°C) have been tested on the germination of tropical palm seeds but may not promote a dormancy break (Martin et al 1996, Rodrigues-Junior et al 2016.…”