Freeze-substitution transmission electron microscopy of gentian shoot tips cryopreserved at ultra low temperatures.

Transmission electron microscopy (TEM) combined with freeze substitution was employed to examine the ultrastructure of cells of gentian shoot tips cooled to the ultra-low temperature of slush nitrogen and liquid nitrogen. When shoot tips were cooled in ultra-low temperature without plant vitrification solution 2 (PVS2) treatment, massive ice formation was observed throughout the cells, indicating that severe injury occurred during cooling. In contrast, when shoot tips were treated with PVS2 and subsequently cooled to ultra- low temperatures, no ice crystals were observed in the cells.

Cryopreservation of Plant Genetic Resources.

Cryopreservation encompasses several interconnect disciplines including physiology and cryophysics. This chapter reviews the current techniques for cryopreservation of plant genetic resources (PGRs). Vitrification is an effective ice crystal avoidance mechanism for hydrated cells and tissues.

Cryopreservation of blueberry shoot tips derived from in vitro and current shoots using D cryo-plate technique.

Cryopreservation is an important tool for long-term storage of plant germplasm that is currently used for plant germplasm storage at many institutes worldwide. Recently, novel cryogenic procedures (V and D cryo-plate methods) have been developed. In this study, the most suitable conditions for preserving blueberry shoot tips derived from in vitro and current shoots using the D cryo-plate method were investigated.

Cryopreservation of sugarcane using the V cryo-plate technique.

Background: Sugarcane is a tropical crop of major importance primarily for its high sucrose content. It is difficult to conserve it in the field or in vitro because of biotic and abiotic stresses. Cryopreservation of sugarcane germplasm is an appropriate approach for conserving its genetic diversity.

Cryopreservation for preservation of potato genetic resources.

Cryopreservation is becoming a very important tool for the long-term storage of plant genetic resources and efficient cryopreservation protocols have been developed for a large number of plant species. Practical procedures, developed using in vitro tissue culture, can be a simple and reliable preservation option of potato genetic resources rather than maintaining by vegetative propagation in genebanks due their allogamous nature. Cryopreserved materials insure a long-term backup of field collections against loss of plant germplasm.

Genetic stability assessment of wWasabi plants regenerated from long-term cryopreserved shoot tips using morphological, biochemical and molecular analysis.

This study compared the effect of cryopreserved storage duration of wasabi shoot tips, which derived from the same in vitro mother-plant. We compared the survival of shoot tips and the genetic stability of regenerated plants originating from four experimental groups: shoot tips stored in a -150°C deep-freezer for 10 years; shoot tips stored in liquid nitrogen for 2 h; shoot tips treated with PVS2 vitrification solution; and untreated controls. No significant difference in survival was observed between the four experimental groups.

Development of a cryopreservation procedure using aluminium cryo-plates.

A cryopreservation procedure using an aluminium cryo-plate was successfully developed using in vitro-grown Dalmatian chrysanthemum (Tanacetum cinerariifolium) shoot tips. Shoot cultures were cold-hardened at 5 degree C on MS medium containing 0.5 M sucrose over a period of 20 to 40 days.

Cryopreservation of basal stem buds of in vitro-grown mat rush (Juncus spp.) by vitrification.

An optimal protocol for the cryopreservation of in vitro-grown mat rush (igusa) buds by vitrification has been successfully developed. Established multiple stemmed cultures, which were induced in liquid MS medium containing 8.9 microM BA by roller culture, were cut into small clumps, plated on solid MS medium and cultured for three weeks at 25 degree C.

Cryopreservation of shoot apices of in-vitro grown gentian plants: comparison of vitrification and encapsulation-vitrification protocols.

Using vitrification and encapsulation-vitrification protocols, we successfully cryopreserved shoot apices from in-vitro plants of different Gentiana cultivars (lines). Although both protocols gave high survival percentages after storage in liquid nitrogen, the encapsulation-vitrification protocol had several distinct advantages over the vitrification protocol: (i) survival was higher under optimal conditions, (ii) the range of optimal exposure periods to the plant vitrification solution 2 (PVS2) was broader, and (iii) regrowth of cryopreserved shoot apices was apparently more vigorous and faster. Shoot apices from ten cultivars/lines of three Gentiana species (G.