An improved encapsulation protocol for regrowth and conservation of four ornamental species

The encapsulation technology, initially developed for clonal propagation through the production of synthetic seeds with somatic embryos, is currently proposed for use with non-embryogenic explants, such as buds and nodal segments (unipolar propagules). In the present study, the encapsulation procedure and its effect on shoot regeneration were evaluated. Apical buds isolated from shoot cultures of four ornamental species (Photinia × fraseri Dress., Polygala myrtifolia L., Metrosideros excelsa Soland. ex Gaertn., and Rosa) were encapsulated in 3% sodium alginate. Effects of complexation time, sucrose concentration, and storage temperature on the regrowth ability of propagules were assessed. With the appropriate combination of sucrose concentration and polymerization time, the encapsulated explants proved to have a better regrowth (80–100%) after sowing than the naked ones. In addition, medium-term storage of Metrosideros encapsulated explants promoted a high level of regrowth (74%) after 4 months in the dark at 10°C; while polygala beads were preserved up to 8 months regardless of storage temperatures. Potential current applications of encapsulation technology and the future use of beads in vivo conditions are also discussed

Cryopreservation of quince (Cydonia oblonga mill.)

BACKGROUND: Quince (Cydonia oblonga Mill.) has great potential for utilisation in pharmaceutical and food industries. OBJECTIVE: The study was to develop an efficient cryopreservation approachfor quince. METHODS: Factors on the survival and regrowth such as cold acclimation, explant type and recovery media composition were assessed. The effectiveness of the resultant protocols for a number of quince cultivars was determined. RESULTS and CONCLUSION: Quince shoot tips and nodal sections are successfully cryopreserved. Sustained regrowth of quince ‘Angers A’ was observed after encapsulation-osmoprotection/dehydration, encapsulation-dehydration and PVS2 vitrification. The highest regrowth rate (80%) was obtained from explants excised from cold hardened shoots and cryopreserved using encapsulation-osmoprotection/dehydration and vitrification protocols. The optimised vitrification protocol in combination with shoot cold hardening and a MS recovery mediumwithout activated charcoal and auxin resulted in satisfactory regrowth of shoots from six quince cultivars. The morphology of acclimatised plants derived from cryopreserved shoots was comparablewith non-cryopreserved plants.Ayesha Siddika is grateful to the University of Derby for the research studentship. The authors acknowledge the Commission of European Union for funding 196 support through CRYMCEPT (Establishing Cryopreservation Methods for Conserving European Plant Germplasm Collections, Quality of Life and Management of Living Resources, QLK5-CT-2002-01279) and CRYOPLANET, COST Action 871 (Establishing Cryopreservation of Crop Species in Europe ). Maurizio Lambardi thanks the Ente Cassa di Risparmio of Florence for the support for this study (project POLICENTRO)

An improved encapsulation protocol for regrowth and conservation of four ornamental species

The encapsulation technology, initially developed for clonal propagation through the production of synthetic seeds with somatic embryos, is currently proposed for use with non-embryogenic explants, such as buds and nodal segments (unipolar propagules). In the present study, the encapsulation procedure and its effect on shoot regeneration were evaluated. Apical buds isolated from shoot cultures of four ornamental species (Photinia × fraseri Dress., Polygala myrtifolia L., Metrosideros excelsa Soland. ex Gaertn., and Rosa) were encapsulated in 3% sodium alginate. Effects of complexation time, sucrose concentration, and storage temperature on the regrowth ability of propagules were assessed. With the appropriate combination of sucrose concentration and polymerization time, the encapsulated explants proved to have a better regrowth (80–100%) after sowing than the naked ones. In addition, medium-term storage of Metrosideros encapsulated explants promoted a high level of regrowth (74%) after 4 months in the dark at 10°C; while polygala beads were preserved up to 8 months regardless of storage temperatures. Potential current applications of encapsulation technology and the future use of beads in vivo conditions are also discussed

Effect of a double phase culture system and activated charcoal on in vitro propagation of Malus sylvestris (L.) Mill.

The effectiveness of a double phase (solid/liquid) culture system (DPS) in comparison to a conventional (solid) system (CS) as well as, the role of various concentrations of activated charcoal in both systems on the enhancement of micropropagation of Malus sylvestris (L.) Mill. were investigated. In this study, lateral shoots were used as primary explants and a comparison for shoots regeneration and rooting abilities was assessed between DPS and CS micropropagation systems. Also, the effect of activated charcoal concentration (0, 250, 500, 1000 mg l-­1) during rooting stage was evaluated for both micropropagation systems. All assessed biometric parameters were higher in the DPS propagation system. The addition of activated charcoal induced effectively rhizogenesis in both systems, whereas the highest value of roots length (13.16 cm) was in the DPS system supplemented with activated charcoal at 500 mg l-­1. The DPS culture system represents a promising low-­cost and time­-saving technique which may improve micropropagation efficiency in producing a large quantity of homogenous wild apple plants

Development of an efficient 'one-step freezing' cryopreservation protocol for a Georgian provenance of chestnut (Castanea sativa Mill.) zygotic embryos.

Experiments were performed to determine the influence of various dehydration and vitrification treatment times on the 'one-step freezing' cryopreservation of embryonic axes (EAs), composed of zygotic embryos and cotyledon residuals, from mature seeds of a Georgian provenance of chestnut (Castanea sativa Mill.). Dehydration was carried out in laminar flow hood from 1 to 5 h, and vitrification experiments were carried out by immersion of EAs in PVS2 vitrification solution up to 120 min, both followed by direct immersion in liquid nitrogen. Both systems resulted in inducing specimen tolerance to ultra-rapid freezing, although to a different extent. Full germination of cryo-stored EAs after 5 h of dehydration (reducing moisture content from initial 66% to 21%) has been increased from 0% to 66.7%. A pre-treatment of EAs in PVS2 vitrification solution for 30 min produced fully developed plantlets at a rate of 55.6% in post-cryopreservation. Plantlet regrowth from cryopreservation was faster in EAs that underwent the dehydration/'one-step freezing' procedure. All the plantlet from cryopreserved EAs could be easily acclimatized, producing healthy potted plants. Finally, the TTC test showed to be useful for a fast evaluation of specimen survival after thawing and, as a consequence, to speed up the development of optimized cryo-protocols. ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 4, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. ********

Plant Cryopreservation: A Look at the Present and the Future

Cryopreservation is known as an applied aspect of cryobiology or the study of life at low temperatures [...

Encapsulation of Shoot Tips and Nodal Segments for in Vitro Storage of “Kober 5BB” Grapevine Rootstock

In vitro preservation of the “Kober 5BB” rootstock (Vitis berlandieri × Vitis riparia) was assessed with the encapsulation technique and slow growth storage. Shoot tips and nodal segments excised from in vitro cultures were encapsulated in calcium-alginate beads. A 30 min ion exchange time proved optimal for forming proper beads. The encapsulated and naked explants were stored at 4 °C in the dark or light. After 9 months of cold storage, the highest regrowth, 83.3%, was recorded for the encapsulated shoot tips maintained in darkness. The development of the encapsulated nodal segments was 55.6% under the same storage conditions. The encapsulated explants had a better regrowth capacity after storage than the naked explants

Application of cryopreservation to the long-term storage of poplar and aspen (Populus spp.) germplasm

vokMyynti MTT, Tietopalvelut 31600 Jokioine

In Vitro Conservation through Slow Growth Storage Technique of Fruit Species: An Overview of the Last 10 Years

Plant genetic resources conservation may be a potential option for the improvement of agricultural crops through modern biotechnologies, and in vitro conservation is a tool available to safeguard plant biodiversity. Ex situ conservation of plant genetic resources using the in vitro procedures is in progress in many countries. The slow growth storage (SGS) technique is a valid in vitro approach to preserve several vegetatively propagated species by controlling the growth and development of plantlets, economizing storage space and labor and reducing costs. Moreover, SGS prolongs the timing between subcultures, lowers the risk of losing germplasm through handling errors, such as contamination problems, and decreases the risk of genetic instability due to the reduction in the number of subcultures. SGS is applied by considering different factors: temperature, light or darkness conditions, medium composition, including mineral or sucrose concentrations, and the presence/absence of plant growth regulators, osmotic agents and growth inhibitors. SGS protocols for some fruit species have been well defined, others require additional research. The present review focuses on the effect of several factors that influence the SGS of in vitro shoots derived from temperate and tropical fruit species during the last ten years