Articles
CRYOPRESERVATION OF POTATO CULTIVARS – DESIGN OF A METHOD FOR ROUTINE APPLICATION IN GENEBANKS
Article number
447_97
Pages
477 – 482
Language
Abstract
To improve germplasm preservation of potato cultivars many attempts have been made to freeze potato meristems in the past.
Slow freezing, ultra rapid freezing, vitrification as well as encapsulation/dehydration have been successfully applied for cryopreservation.
Nevertheless all methods have only been applied to a single or a few cultivars and under conditions of academic research.
Our aim was to design a method suitable for routine genebank work, which provides high sample throughput, low costs, fitting into a working days time schedule, low susceptibility to errors and applicability to a broad range of different potato cultivars.
Working at suboptimum conditions for a specific cultivar was accepted as long as plants could be regenerated.
The method developed is based on ultra rapid freezing.
Apical shoot tips were incubated in DMSO, transferred into 2,5 ml droplets placed on small leaflets of aluminium foil and immersed directly into liquid nitrogen.
Under these conditions the droplets stick to the aluminium foil and the leaflets can be stored in cryovials.
Tests to compare different methods for the pregrowth of mother plants, type and size of meristems, methods for cryoprotection and pregrowth stimulation after thawing have been carried out.
The method could be applied routinely without adaptations to more than 150 different cultivars up to now.
Genetic stability was tested by phenotypical inspection of regrown plants and tubers, flow cytometry and DNA fingerprinting.
Only one polyploid was found.
From 161 tested samples no polyploids or abnormal banding patterns have been found.
The developed method is applicable for routine genebank work and provides a safe cryopreservation method for potato cultivars.
Slow freezing, ultra rapid freezing, vitrification as well as encapsulation/dehydration have been successfully applied for cryopreservation.
Nevertheless all methods have only been applied to a single or a few cultivars and under conditions of academic research.
Our aim was to design a method suitable for routine genebank work, which provides high sample throughput, low costs, fitting into a working days time schedule, low susceptibility to errors and applicability to a broad range of different potato cultivars.
Working at suboptimum conditions for a specific cultivar was accepted as long as plants could be regenerated.
The method developed is based on ultra rapid freezing.
Apical shoot tips were incubated in DMSO, transferred into 2,5 ml droplets placed on small leaflets of aluminium foil and immersed directly into liquid nitrogen.
Under these conditions the droplets stick to the aluminium foil and the leaflets can be stored in cryovials.
Tests to compare different methods for the pregrowth of mother plants, type and size of meristems, methods for cryoprotection and pregrowth stimulation after thawing have been carried out.
The method could be applied routinely without adaptations to more than 150 different cultivars up to now.
Genetic stability was tested by phenotypical inspection of regrown plants and tubers, flow cytometry and DNA fingerprinting.
Only one polyploid was found.
From 161 tested samples no polyploids or abnormal banding patterns have been found.
The developed method is applicable for routine genebank work and provides a safe cryopreservation method for potato cultivars.
Authors
A. Schäfer-Menuhr, H. Martin Schumacher, G. Mix-Wagner
Keywords
Solanum tuberosum L., germplasm preservation, apical meristems, shoot tips, ultra rapid freezing, flow cytometry, DNA fingerprinting
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