CRYOPRESERVATION TECHNIQUES FOR THE LONG-TERM STORAGE OF MAHOGANY (SWIETENIA MACROPHYLLA) SEEDS

Abstract

Research on cryopreservation of mahogany seeds (with and without testa) and embryonic axes was carried out using liquid nitrogen either by direct immersion or slow cooling. The best treatment for seeds was six hours desiccation, without testa, using a slow cooling regime, which resulted in 77% survival. The moisture content after six hours desiccation was 5.59%. The initial moisture content of the excised embryos was 11.52% and viability at this moisture was 97%. The best pretreatment for axes before cryopreservation was six hours desiccation (resulting in a 4.59% moisture content) in which 63% survival was obtained after direct immersion in liquid nitrogen. By comparison 87% of the embryonic axes survived cryopreservation using the slow cooling technique.