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Title: Cryopreservation of Ribes nigrum cultivars maintained in vitro and in the field
Author: Green, Jonathan Edward
ISNI:       0000 0004 2669 2551
Awarding Body: University of Essex
Current Institution: University of Essex
Date of Award: 2008
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A range of Ribes cultivars of different geographical orlgm find recognised horticultural 'hardiness', have been investigated with respect to foliar and winter responses to freezing. Differences were observed in the freezing responses of actively-growing foliar material given cold pretreatments but no significant effects persisted below -10°C, suggesting that the selected cultivars possess little in the way of genetically determined cold response that might be exploited in ultra-low temperature cryopreservation. Differences were observed between cultivars in their ability to cold harden, and a rootstock with high cold hardening ability was able to significantly increase the foliar hardiness of a scion with lesser cold hardening ability. This improvement did not extend beyond performance -10°C. The natural cold hardiness of overwintering buds was exploited in a simple and effective cryopreservation protocol that used field material directly with a -20°C pretreatment in a conventional freezer, did not require cryoprotectants and needed only a single passage of in vitro culture. Geographical origin did not appear to be related to survival following freezing at 20° C and -196°C (LN). The biochemical responses of in vitro material of selected cultivars to the various stages of cryopreservation showed some significant differences, largely with respect to protein changes, but there was no clear pattern of response for any of the selected criteria. However, both before and after low temperature treatment, reproducible biochemical differences were seen between two accessions of the cultivar Ojebyn from different, accredited sources. This material has shown stable, phenotypic differences over several subsequent field seasons suggesting the possibility of genetic or epigenetic change as a consequence of in vitro maintenance. The field material has subsequently been transferred to the University of Copenhagen where DNA fingerprinting will be carried out on material from 2007.
Supervisor: Not available Sponsor: Not available
Qualification Name: Not available Qualification Level: Doctoral
EThOS ID:  DOI: Not available