Germination and effects of storage of fruits of Prosopis ruscifolia (Fabaceae)

Abstract

Prosopis ruscifolia is a promising forest species for restoration of saline areas that produces high quality wood and nutraceutical interest fruits. Its germination requirements and optimal storage conditions are unknown. The objectives of the work were 1) to evaluate different methods to stimulate germination, 2) to establish if there is an interaction between pregerminative treatments and the substrate used in laboratory tests (paper or sand), and 3) to analyze the effect of three different conditions of fruit storage on germination. Normal seedlings (PG), abnormal seedlings, hard and dead seeds were recorded. Three fruit samples were stored for eight months at 7 ± 2 °C, -17 ± 2 °C and the control at 25 °C. Afterwards, germination tests were carried out and the speed indexes (IVG) and mean germination time (TMG) were determined. Results indicated that chemical scarification with sulfuric acid was the most efficient pregerminative treatment to stimulate germination in both substrates. Immersion in water at room temperature showed the lowest percentage of germination in both substrates. The seeds of fruits stored at 7 ± 2 ° C had the highest germination percentage. Low temperatures improved velocity indices (IVG) and mean germination time (TMG). Results indicated the need for methods to overcome seed dormancy in P. ruscifolia and the excellent tolerance to low temperatures during fruit storage.