Reserve mobilization and in vitro germination of Euterpe edulis (Martius) seeds at different maturation stages

Abstract

Euterpe edulis (Arecaceae) is a typical palm of the Atlantic Forest with great ecological and economic value. Its seeds are characterized by hard coats, as well as recalcitrant, slow, and uneven germination, which hinder efficient seedling production. Given its risk of extinction, the objective of this study was to investigate reserve mobilization and how this impacted on the quality of maturing E. edulis seeds. Seven maturation stages separated by 20-day intervals, were assessed from 108 to 228 days after anthesis. The morphological characteristics, germination, vigor, and biochemical properties of in vitro germinated seeds, as well as the quality of the seedlings from each maturation stage were assessed. Four replications with ten seeds were evaluated at each stage. Over the experimental period, total relative growth rate of the fruits was 0.0037 mm day− 1, while moisture content decreased from 79.49 to 46.59%. The concentrations of phenols, soluble sugar, proteins, and starch decrease significantly during maturation, while there is an increase in lipids and fibers. Most variables displayed a positive correlation, except moisture, phenols, soluble sugar, proteins, and starch. E. edulis seeds possessed sufficient reserves to allow for normally developed embryos 148 days after anthesis, their 100% germination, and formation of 100% normal seedlings.