Constant relative humidity chambers using phosphoric acid for controlled desiccation of small recalcitrant biological samples
| Autor: | Masaya Ishikawa, P.V. Hemachandra, T. Kitashima, T. Toyomasu, E. Yamaguchi |
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| Rok vydání: | 2005 |
| Předmět: | |
| Zdroj: | Seed Science and Technology. 33:741-752 |
| ISSN: | 1819-5717 0251-0952 |
| DOI: | 10.15258/sst.2005.33.3.22 |
| Popis: | For successful storage and cryopreservation of recalcitrant (short-lived or desiccation-sensitive) plant seeds, excised seed embryos or pollen, precise control of water content and/or slow drying rates are often crucial. To realize such controlled desiccation, we developed simple and safe constant relative humidity (RH) chambers using a single compound, phosphoric acid (PA). It consisted of a bowl of PA-water solution placed in a hermetically sealed box. With this apparatus, RH ranges of 4-88% were obtained from 100-10% PA solutions, respectively. Similar RH-PA concentration profiles were obtained at 24 and 7°C. Constant RH was ensured at a constant temperature as temperature fluctuations resulted in mirror-image RH oscillations within the chamber. When the temperature was greatly changed within 5-30°C ranges, the chamber regained the same equilibrium RH in 4-8 h. Using this system, typical recalcitrant winter rye pollen was successfully stored under RH50% at 7°C for 10 days. Alginate beads, irrespective of sucrose concentrations (0.7-1.2 M), were desiccated to equilibrium water contents of 11.5-32% (fresh weight basis) under constant RH of 27-78% at 24°C. This system is simple, economical and safer than conventional RH chamber systems using saturated solutions or sulfuric acid. It allows constant RH available at various temperatures and is useful for controlled desiccation of small recalcitrant genetic or in vitro resources for dry-cold or cryogenic storage. |
| Databáze: | OpenAIRE |
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