Cryopreservation of Ornamental Plants

Transcription

1 Cryopreservation of Ornamental Plants Adela Halmagyi Institute of Biological Research, branch of NIRDBS, Republicii str. 48, Cluj-Napoca, Romania

2 Cryopreservation benefits for ornamental plants long-term conservation of vegetatively propagated species; recalcitrant seeds or no viable seeds are formed; endangered, rare or endemic wild species for ecological reasons; wild species as a source of special traits; old cultivars and land races or breeding lines; loss of plants by diseases and climatic stress; eliminate somaclonal variation; provides long-term genetic stability; 2

3 Plant material Selection of species and cultivars of interest roses (Rosa x hybrida L.) carnation (Dianthus caryophyllus L.) ornamental citrus species Explants type (shoot apices, axillary nodes, seeds); age of plants (duration in culture); dimension of explants; 3

4 Overview of the cryopreservation methods Cryopreservation method / technique Plant species Abb. ultra-rapid freezing droplet-vitrification (PVS2) rose, carnation D-V encapsulation-dehydration carnation E-D encapsulation-vitrification seeds carnation citrus E-V

5 Results Rose D-V Effect of PVS2 treatment duration on post-thaw regrowth of cryopreserved rose small (1-2 mm) and large (3-4 mm) shoot tips. (a) cv. Kardinal, (b) cv. Fairy, (c) cv. Maidy. Halmagyi A, Pinker I (2006) Plant Cell Tiss Org Cult 84,

6 Rose D-V Effect of sucrose preculture on regrowth of cryopreserved rose shoot tips. Sucrose conc. (M) Duration of preculture (h) cv. Kardinal Shoot development (% ± SD) cv. Fairy cv. Maidy No preculture ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± ± 4.81 Shoot tips (3-4 mm in length) were precultured for 24 and 48 h in liquid medium supplemented with sucrose and treated with PVS2 for 20 min prior to freezing in liquid nitrogen. 6

7 Carnation D-F Shoot formation from carnation shoot tips, following incubation (at 0 C or 24 C) in DMSO, direct immersion in liquid nitrogen, thawing and plating on culture medium. A) cv. Anthares; B) cv. Coralie; C) cv. Kinero; D) cv. Pallas; E) cv. Pink Candy; F) cv. Wanessa. Halmagyi A, Lambardi M (2006) In: Floriculture, Ornamental and Plant Biotechnology. Advances and Topical Issues. Vol. II. (Teixeira JA ed.). 7

8 Carnation D-V Effect of exposure to PVS2 at 0ºC on post-thaw recovery of cryopreserved carnation shoot tips. a) cv. Anthares, b) cv. Coralie, c) cv. Kinero, d) cv. Pallas, e) cv. Pink Candy, f) cv. Wanessa. 8

9 Carnation E-D Regeneration of carnation shoot tips after cryopreservation by encapsulation-dehydration. A) cv. Anthares, B) cv. Coralie, C) cv. Kinero, D) cv. Pallas, E) cv. Pink Candy, F) cv. Wanessa; Shoot tips were precultured in sucrose (0.5 or 0.75 M), partially dessicated in laminar air-flow and directly immersed in liquid nitrogen. 9

10 Carnation E-V Effect of PVS2 exposure time on shoot regrowth from encapsulated carnation shoot tips following cryopreservation; (a) cv. Pallas, (b) cv. Pink Candy, (c) cv. Wanessa. Shoot tips (2-3 mm in length) were encapsulated, precultured in sucrose, dehydrated in PVS2 at 24ºC and directly immersed into liquid nitrogen. Halmagyi A, Deliu C. (2007) Sci Hortic 113,

11 Citrus - seeds Table 3. Effects of different dehydration levels, followed or not by cryopreservation, on citrus seed moisture content and germinability. Species MC (% FW) Dehydration (h) Final seed MC Germinability (%) Dehydrated (-LN) Dehydrated (+LN) C. aurantium Foetifera C. aurantium x C. paradisi C. volkameriana 34 C. lumia Pyriformis 41 C. sinensis Lambardi M, Halmagyi A, Benelli C, De Carlo A, Vettori C. (2007) Adv in Hort Sci 21(4),

12 Concluding remarks the most important goal of the cryostorage is the recovery of true-to-type plants; appropriate choice of technique depends on the type of plant material, existing facilities, etc.; the quality of explants is essential to ensure homogeneity of plant material; take effective measures too prevent dehydration and osmotic shock during excision of shoot tips; development of the best rewarming techniques and growth media is essential for the success of any protocol; protocol optimization is crucial for success. 12