Sub-freezing effect on viability of Anadenanthera peregrina (L.) Speg. seeds with different moisture contents

Abstract

Angico (Anadenanthera peregrina (L.) Speg.) is a forest species, Leguminoseae-Mimosoideae, occuring from the Amazon Region down to the Southeast of Brazil, mainly in the savannas. It is used in urban landscaping and tannage, due to the high tannin content (15-20%) of its bark. The purpose of this work was to study angico seed behaviour under different moisture contents and storage conditions, aiming at the establishment of methods for germplasm preservation. Seeds were submited to the following treatments: seeds with 5.56% initial moisture content (control); seeds hydrated until reach 8.24% moisture content; seeds hydrated (8.24%) and dehydrated to 4.37%, and seeds hydrated (8.24%) and dehydrated to 3.51%. After these treatments, seeds were packed in sealed trifoliated bags and stored for 72 hours at environmental temperature, -20 ºC (freezer) and -196 ºC (liquid nitrogen). Seed parameters evaluated were germination, vigor and water uptake. Viability was maintained in each one of the storage methods, distinguishing, however, the better performance of hydrated seeds (8.24% moisture content) stored at liquid nitrogen. It was evident from the results obtained that seeds of this species presented orthodox behaviour, as they were tolerant to drying and freezing at sub-zero temperatures.