K van der Walt1, P Kemp2, S Sofkova-Bobcheva2, D Burritt3, J Nadarajan4. 1. Otari Native Botanic Garden and Wilton's Bush Reserve, Wellington City Council, 160 Wilton Road, Wellington; Massey University of New Zealand, Private Bag 11222, Palmerston North, New Zealand. Karin.vanderwalt@wcc.govt.nz. 2. Massey University of New Zealand, Private Bag 11222, Palmerston North, New Zealand. 3. University of Otago, Department of Botany, P.O. Box 56, Dunedin, New Zealand. 4. Massey University of New Zealand, Private Bag 11222, Palmerston North; the New Zealand Institute for Plant and Food Research Limited, Private Bag 11600, Palmerston North, New Zealand.
Abstract
BACKGROUND: Syzygium maire is a threatened tree species with limited information on long-term storage options for its recalcitrant seed. OBJECTIVE: To evaluate the cryopreservation of S. maire zygotic embryo axes (EA) using dehydration, encapsulation-dehydration as well as PVS2 vitrification using droplet vitrification (DV) and the novel droplet vacuum infiltration vitrification (DVIV) methods. MATERIALS AND METHODS: Excised naked and sodium alginate encapsulated EA were desiccated to various moisture contents (MC) using a laminar flow cabinet. Moisture content, embryo survival and plantlet formation, before and after cryopreservation, were assessed at 1 h intervals during the desiccation period (0-6 h). The influence of PVS2, using DV and DVIV, was assessed for various desiccation times and temperatures. RESULTS: Encapsulated EA desiccated to 31% and 37% MC survived but no plantlets formed following cryopreservation. Exposure to PVS2 using the DV method had a negative impact on embryo survival and plantlet formation, while DVIV resulted in improved results for non-cryopreserved EA. However, neither PVS2 vitrification method resulted in embryo survival following cryopreservation. CONCLUSION: S. maire embryos are sensitive to desiccation and likely require physical, chemical or a combination of protection methods to increase embryo survival and plantlet formation following cryopreservation.
BACKGROUND: Syzygium maire is a threatened tree species with limited information on long-term storage options for its recalcitrant seed. OBJECTIVE: To evaluate the cryopreservation of S. maire zygotic embryo axes (EA) using dehydration, encapsulation-dehydration as well as PVS2 vitrification using droplet vitrification (DV) and the novel droplet vacuum infiltration vitrification (DVIV) methods. MATERIALS AND METHODS: Excised naked and sodium alginate encapsulated EA were desiccated to various moisture contents (MC) using a laminar flow cabinet. Moisture content, embryo survival and plantlet formation, before and after cryopreservation, were assessed at 1 h intervals during the desiccation period (0-6 h). The influence of PVS2, using DV and DVIV, was assessed for various desiccation times and temperatures. RESULTS: Encapsulated EA desiccated to 31% and 37% MC survived but no plantlets formed following cryopreservation. Exposure to PVS2 using the DV method had a negative impact on embryo survival and plantlet formation, while DVIV resulted in improved results for non-cryopreserved EA. However, neither PVS2 vitrification method resulted in embryo survival following cryopreservation. CONCLUSION: S. maire embryos are sensitive to desiccation and likely require physical, chemical or a combination of protection methods to increase embryo survival and plantlet formation following cryopreservation.
Authors: Lyndle K Hardstaff; Karen D Sommerville; Bryn Funnekotter; Eric Bunn; Catherine A Offord; Ricardo L Mancera Journal: Plants (Basel) Date: 2022-04-08