The current status of plant genetic diversity in Turkey and implications for cryopreservation studies

Abstract

At the moment, cryopreservation techniques have not yet been put into practice in Turkey, but in 2005 studies were initiated at the Gebze Institute of Technology in order to develop effective procedures for the conservation at -196°C of seeds and embryonic axes from valuable germplasm. Important results have already been obtained for Pistacia spp. and Arachis hypogaea. Hulled seeds (embryos plus cotyledons) from three Pistacia species (P. vera, P. terebinthus and P. lentiscus) showed the capacity to be stored in liquid nitrogen after the application of an appropriate dehydration/one-step freezing protocol. A maximum of 90% germinability was obtained when P. vera seeds underwent 8 hr of dehydration over silica gel prior to their direct immersion in liquid nitrogen. In P. terebinthus and P. lentiscus, shorter periods of dehydration (1 hr and 15 min, respectively) were sufficient to achieve the best germination percentages (16% and 47%, respectively). In the case of Arachis hypogaea, effective one-step freezing procedures, based on vitrification or dehydration of embryonic axes, were developed for the cv. Virginia. The best protocol (100% germination) involved a 2.5-hr pre-dehydration of embryonic axes in sterile air flow. The optimized protocols were then applied to three Turkish cultivars, resulting in high recovery percentages. © 2008 Elsevier B.V., All rights reserved.