Regeneration of Dioscorea floribunda Plants from Cryopreserved Encapsulated Shoot Tips: Effect of Plant Growth Regulators
Abstract:The encapsulation-dehydration protocol for the cryopreservation of in vitro shoot tips of Dioscorea floribunda was optimized. Maximum survival of 87% was obtained when overnight pretreatment with 0.3 M sucrose was followed by encapsulation, preculture in 0.75 M sucrose for 4 d, dehydration in a laminar air flow for 5½ h, quenching in liquid nitrogen and thawing at 40°C. During recovery growth, 29% shoot formation was obtained when cryopreserved shoot tips were initially cultured for 25 d on a medium with 1.5 mg l-1 BAP, 0.2 mg l-1 NAA and 0.2 mg l-1 GA3 followed by culturing for 15 d on a medium with reduced BAP (1 mg l-1) but increased NAA (0.5 mg l-1) and GA3 (0.3 mg l-1). Finally, transfer on to a medium with further reduced doses of BAP (0.05 mg l-1) and NAA (0.15 mg l-1) but without GA3 stimulated production of fully grown plantlets. All plants regenerated without callus formation. Modification of post-thaw culture media with plant growth regulators was essential for regrowth of shoot tips to plantlets.
Document Type: Research Article
Publication date: 2007-09-01
CryoLetters is a bimonthly international journal for low temperature sciences, including cryobiology, cryopreservation or vitrification of cells and tissues, chemical and physical aspects of freezing and drying, and studies involving ecology of cold environments, and cold adaptation
The journal publishes original research reports, authoritative reviews, technical developments and commissioned book reviews of studies of the effects produced by low temperatures on a wide variety of scientific and technical processes, or those involving low temperature techniques in the investigation of physical, chemical, biological and ecological problems.