Viability, germination, and storage of pollen from açaí palms and their implications for genetic conservation and breeding

Abstract

Assessments of pollen viability can facilitate the enhancement of genetic breeding and resources conservation of Euterpe oleracea Mart. and E. precatoria Mart., species of socioeconomic relevance in the Amazon. This study aimed to evaluate the pollen viability of both species through colorimetric and in vitro germination tests, as well as analyze the effects of pollen storage temperatures and durations. Coloring methods using tetrazolium, trypan blue and cotton blue were tested, and a germination test was performed in medium with concentrations of sucrose, calcium, and boron. Cotton blue (0.05 %) presented the greatest efficiency, practicality, and reproducibility, with viability values exceeding 85 % for both species. The stored pollen maintained a viability above 70 % for up to 180 days, with a better performance at -20 ºC, a more economical and stable condition for conservation. For the in vitro germination, the medium containing 100 g L-1 of sucrose and 300 mg L-1 of Ca(NO₃)₂·4H₂O provided the highest germination rates, whereas the addition of boron alone reduced the response. The pollen of the two species presents adequate viability when stored for use in controlled hybridization and genetic conservation by means of a pollen bank.

KEYWORDS: Euterpe oleracea, Euterpe precatoria, in vitro germination.