INVESTIGADORES
ZARITZKY Noemi Elisabet
artículos
Título:
Partial dehydration and cryopreservation of Citrus seeds
Autor/es:
GRAIVER NATALIA; CALIFANO A; ZARITZKY NOEMI.
Revista:
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
Editorial:
JOHN WILEY & SONS LTD
Referencias:
Lugar: LOndres; Año: 2011 vol. 91 p. 2544 - 2550
ISSN:
0022-5142
Resumen:
BACKGROUND: Three categories ofseed storage behavior are generally
recognized among plant species:orthodox, intermediate and recalcitrant.
Intermediate seeds cannot be stored in liquid nitrogen (LN) without a previous
partial dehydration process.
The
water content (WC) of the seeds at the moment of immersion in LN must be
regarded as the most critical factor in cryopreservation. The purpose of this
studywas to investigate the basis of the optimal hydration status for
cryopreservation of Citrus
seeds: C. sinensis (sweet orange), C. paradisi (grapefruit), C. reticulata (mandarin) in LN.
RESULTS:
To study the tolerance to dehydration and LN exposure, seeds were desiccated by
equilibration at relative humidities between 11 and 95%. Sorption isotherms were
determined and modeled; lipid content of the seeds was measured. Seed desiccation
sensitivity was quantified by the quantal response model. Differential scanning
calorimetry (DSC) thermograms were determined on cotyledon tissue at different
moisture contents to measure ice melting enthalpies and unfrozen WC.
Samples
of total seed lipid extract were also analyzed by DSC to identify lipid
transitions in the thermograms.
CONCLUSIONS:
The limit of hydration for LN Citrus seeds treatment corresponded to the unfrozen
WC in the tissue, confirming that seed survival strictly depended on avoidance
of intracellular ice formation.