Potencial de disseminação e aspectos morfoanatômicos de sementes de espécies da caatinga contidas em cíbalas de caprinos e ovinos

Abstract

The Brazilian Northeast region is the main producer of national sheep and goat herds, which are considered efficient seed dispersing agents and can promote improvements in germination. Thus, the objective of this work was to evaluate the effect of the passage of seeds of Caatinga species through the digestive system of goats and sheep on the recovery, anatomy and physiological quality of seeds. Initially, an experiment was set out with eight Saanem goats, being adopted as treatments the passage of the seeds through the digestive system of goats and nine periods of ingestion (12, 24, 36, 48, 60, 72, 84, 96 and 108 hours) and four forest species - Piptadenia stipulacea (Benth.) Ducke, Mimosa tenuiflora Willd., Desmanthus virgatus L. and Mimosa caesalpiniifolia Benth., and an additional treatment (intact seeds). There was recovery of the seeds of the four species after passing through the digestive system, with the beneficial effect being the germination of P. stipulacea and D. virgatus. A second of experiments was carried out, using 24 animals (12 goats and 12 sheep) and the recovery periods of excreted seeds and an absolute control (intact seeds). For D. virgatus and M. tenuiflora, there was seed recovery up to 120 hours after passing through the digestive system, while for M. caesalpiniifolia, it lasted up to 192 hours, with the highest amount of seeds recovered after 48 hours for all plants. species, both in goats and sheep. For D. virgatus, passing the seeds through the digestive system for 24 hours in goats and for 24 and 120 hours in sheep promotes improvements in germination. In M. tenuiflora, retention for 120 hours in goats and 96 hours in sheep improves germination. While for M. caesalpiniifolia, the passage for 120 and 168 hours in goats and 96 in sheep, provides greater germination and seed vigor. The anatomical analysis of the tegument of M. tenuiflora and M. caesalpiniifolia, indicates that during the passage of the seeds through the digestive system of goats and sheep, causes the scarification of the tegument in the different evaluation periods.