G M Volk1, A N Shepherd2, R Bonnart2. 1. USDA-ARS National Center for Genetic Resources Preservation, 1111 S. Mason St., Fort Collins, CO 80521. Gayle.Volk@ars.usda.gov. 2. USDA-ARS National Center for Genetic Resources Preservation, 1111 S. Mason St., Fort Collins, CO 80521.
Abstract
BACKGROUND: Secure back-up of Vitis genetic resource collections requires cryopreservation methods that give long-term survival of clonal germplasm having diverse genetic backgrounds. OBJECTIVE: This work sought to increase survival of Vitis shoot tips exposed to liquid nitrogen using combinations of pretreatments and cryoprotection procedures. The new procedure should give high survival of shoot tips from a wide range of Vitis species. MATERIALS AND METHODS: In vitro plants from nine Vitis species were used as source material for nodal sections. Shoot tips were then excised from nodal sections that were grown on medium containing benzyladenine, salicylic acid, glutathione, and ascorbic acid. The shoot tips were treated with loading solution, and then half-strength PVS2 for 30 minutes, prior to full-strength PVS2 treatments for between 60 and 90 minutes prior to liquid nitrogen (LN) exposure. RESULTS: Shoot tip regrowth levels were highest 90 minutes in PVS2+LN and ranged from 24-43% and averaged 35±2% across the nine Vitis species. CONCLUSION: The pretreatment, cryopreservation, and recovery methods yielded successful regrowth for multiple Vitis species using a droplet-vitrification procedure.
BACKGROUND: Secure back-up of Vitis genetic resource collections requires cryopreservation methods that give long-term survival of clonal germplasm having diverse genetic backgrounds. OBJECTIVE: This work sought to increase survival of Vitis shoot tips exposed to liquid nitrogen using combinations of pretreatments and cryoprotection procedures. The new procedure should give high survival of shoot tips from a wide range of Vitis species. MATERIALS AND METHODS: In vitro plants from nine Vitis species were used as source material for nodal sections. Shoot tips were then excised from nodal sections that were grown on medium containing benzyladenine, salicylic acid, glutathione, and ascorbic acid. The shoot tips were treated with loading solution, and then half-strength PVS2 for 30 minutes, prior to full-strength PVS2 treatments for between 60 and 90 minutes prior to liquid nitrogen (LN) exposure. RESULTS: Shoot tip regrowth levels were highest 90 minutes in PVS2+LN and ranged from 24-43% and averaged 35±2% across the nine Vitis species. CONCLUSION: The pretreatment, cryopreservation, and recovery methods yielded successful regrowth for multiple Vitis species using a droplet-vitrification procedure.