Cryopreservation of Strawberry Meristems and Mass Propagation of Plantlets1

Abstract

Meristems isolated from strawberry (Fragaria X ananassa Duch. cv. Redcoat) runner-tips were cultured on a Murashige and Skoog (MS) medium supplemented with 6-benzylamino purine (BA), indolebutyric acid (IBA) and gibberellic acid (GA3) at concentrations of 1, 1 and 0.1 μm, respectively. The meristems regenerated shoots within 3 to 4 weeks when incubated at 26°, 16 hour photoperiods and 4000 lux intensity. On medium supplemented with BA at a concentration of 10 μm these shoots proliferated into “clumps,” each consisting of 150 to 200 shoots. Meristems isolated from these in vitro shoots were precultured on medium supplemented with dimethylsulfoxide (DMSO) or glycerol as cryoprotectants, frozen either slowly at cooling velocities of 0.5° to 1.0°C/minute to −40° or rapidly and stored in liquid nitrogen (−196°). Maximum viability and plant regeneration (95%) was obtained when the meristems were precultured on medium supplemented with 5% DMSO, and then frozen at a cooling velocity of 0.84°/min. A viability of 35% was observed when meristems precultured on 5% glycerol-supplemented medium for 3 days were frozen at a cooling velocity of 0.94°/min. Rapid freezing and rapid dry freezing using either DMSO or glycerol resulted in reduced viability. A viability and plant regeneration frequency of 95% was obtained after the meristems were in storage for one week in liquid nitrogen. From samples assayed after 8 weeks of storage in liquid nitrogen, more than 55% of the meristems regenerated into plantlets.

Acclimatization of ex Vitro Strawberry Plantlets in CO2-enriched Environments and Supplementary Lighting

“…Apical meristems of strawberry crowns ('Kent' and 'Honey oye') were excised according to Boxus (2). After an initiation period on Boxus medium (2), the plantlets were transferred to a proliferation medium (16) and subcultured five to six times at regular 4-week intervals. Axillary branches located at the base of cultures then were excised and transferred onto rooting medium.…”

Cryopreservation of in Vitro Established Shoot Tip Explants of Date Palm Cv. Zaghlool

“…Several authors indicated that cold hardening and /or preculturing with a high concentrations of sugar in the medium are essential to successful cryopreservation of In vitro cultured plant materials (Kartha et al, 1979(Kartha et al, , 1980Engelmann et al, 1995;Reed 1988Reed , 1990Reed , 1992Dereddure et al, 1990;Niino, et al, 1992;Kartha and Engelmann 1994).…”

Direct Shoot Regeneration from Strawberry Leaf Disks

“…Tissue culture studies in strawberry primarily have been confined to meristem culture for virus elimination, vegetative propagation, and cryopreservation of germplasm (Boxus et al, 1977;Kartha et al, 1980). However, it recently has been demonstrated that plant regeneration is also possible from both primary and subcultured callus induced on immature leaves (Nehra et al, 1988;Jones et al, 1988).…”