10 research outputs found
Detection of somaclonal variation by random amplified polymorphic DNA analysis during micropropagation of Phalaenopsis bellina (Rchb.f.) Christenson
Phalaenopsis bellina (Rchb.f.) Christenson orchid species are known for their beautiful flower shape, graceful inflorescence and fragrance. Protocorm-like bodies (PLBs) of P. bellina were induced from leaf segments. The PLBs were then subjected to proliferation using ½ strength Murashige and Skoog (MS) media with two subcultures at three months intervals. Twelve decamer random amplified polymorphic DNA (RAPD) primers were used to study somaclonal variation among the mother plant, the initially induced PLBs and proliferated PLBs after 3 and 6 months in culture. Eight out of twelve primers produced 172 bands with 18 polymorphic bands in all the treatments. The amplified products varied between 125 to 8000 bp. Among the primers used, P 16 produced the highest number of bands (29), while primer OPU 10 produced the lowest number (15). The range of similarity coefficient was from 0.83 to 1.0 among the different sub-cultures and mother plant (MP). It was found that minimal or no changes occurred between the MP and the PLBs produced after 3 months of induction. The induced PLBs were then subcultured for six months for proliferation and this resulted in about 17% dissimilarity with MP. It is reported that micropropagation of P. bellina can be carried out successfully using ½ strength MS media for 6 months but further proliferation may result in somaclonal variation which might change the prolific characteristic of this orchids.Key word: Moth orchid, somaclonal variation, random amplified polymorphic DNA, protocorm-like bodies
Dry Sliding-Friction and Wear Behavior of Hot-Extruded Al6061/Si3N4/Cf Hybrid Metal Matrix Composite.
The effects of reinforcement addition and hot extrusion on the microstructures, micro hardness, friction, and wear behavior of aluminium (Al) hybrid composite were investigated. Al6061 dispersed with electroless nickel-coated Si3N4 (6wt.%) and copper-coated carbon fiber (Cf) (1wt.%) hybrid composites was developed through stir casting followed by hot extrusion. Optical micro structural studies confirmed that the size of reinforcements decreased, and their orientations were in the extrusion direction. The decrease in the grain size (29%) of hybrid composites was larger than that in the grain size of matrix alloys under hot-extruded conditions. The synthesized hot-extruded Al6061 hybrid composite exhibited a lower coefficient of friction (51%) and high wear resistance (39%) compared with the hotextruded Al6061base alloy
Fundamental concept of cryopreservation using Dendrobium sonia-17 protocorm-like bodies by encapsulation-dehydration technique
This study was carried out to evaluate the potential of using the encapsulation-dehydration technique on cryopreservation protocorm-like bodies (PLBs) of Dendrobium sonia-17. The survival of the PLBs was assessed based on the effects of 4 dehydration periods (0, 1, 3 and 5 h) and 4 different concentrations of 24-h sucrose pretreatment (0, 0.3, 0.5 and 0.7 M). Upon dehydration, moisture content was determined and the PLBs were evaluated for survival using absorbance values from 2, 3,5- triphenyltetrazolium chloride (TTC) assay at 530 nm and regeneration observations. Moisture content declined with the dehydration time, but the decline was not significant for encapsulated PLBs. All cryopreserved PLBs gave very low survival irrespective of the dehydration period. The best survival percentage in the cryopreservation of the PLBs of Dendrobium sonia-17 was obtained when the combination of 0.5 M sucrose pretreatment and 3 h dehydration time was applied in the experiment.Key words: Dendrobium sonia-17, protocorm-like bodies, encapsulation-dehydration, 2,3,5-triphenyltetrazolium chloride (TTC) assay
A cryopreservation protocol for ex situ conservation of terrestrial orchids using asymbiotic primary and secondary (adventitious) protocorms
© 2015, The Society for In Vitro Biology. In a bid to better conserve endangered terrestrial orchids, we detail cryogenic research using a widely distributed terrestrial orchid, Caladenia latifolia, as a model species for development of cryopreservation for primary (seed generated) and secondary (adventitious) protocorms. Primary protocorm cryopreservation (using droplet vitrification) involved a number of experimental lines of inquiry: investigation of a suitable plant vitrification solution (PVS) by comparing three variants of a standard PVS (2, 3 and 4), determining the most suitable primary protocorm developmental stage for successful cryopreservation, testing the effectiveness of a preculture medium treatment prior to cryopreservation, and investigating temperature preconditioning at the preculture stage as well as different components of the recovery medium. Primary protocorms were generated using asymbiotic in vitro germination media developed by the authors specifically for the test species (half-strength MS macroelements and microelements with 5% (v/v) fresh filter sterilized coconut water). Secondary protocorms were propagated using an in vitro proliferation medium (½ MS with 5 µM a-naphthaleneacetic acid + 2 µM 6-benzylaminopurine). A modified preconditioning step was developed, involving incubation on ½ MS with 0.2 M raffinose for 48 h at 15°C instead of 20°C. The standard recovery medium (½ MS 1 µM zeatin + 0.5 µM gibberellic acid) was replaced after the first week following warming from liquid nitrogen (LN), with asymbiotic germination medium (½ MS + 5% (v/v) coconut water) for the remainder of the recovery phase. This new step increased the survival of primary protocorms from 68 to 85%. The average post-cryostorage regeneration of plants from primary protocorms increased from 17 to 48% after a 6-wk incubation. A similar protocol increased the survival of secondary protocorms from 63 to 84%. Regeneration of plants from secondary cryostored protocorms increased from 11 to 26% after 14 wk. The protocols developed here provide a useful template for advancing cryoconservation of other orchid taxa, particularly rare and threatened species
Synthetic Seed Production of Flower Bulbs
WOS: 000558565200013Flower bulbs are perennial or annual plants with underground structures such as bulb, corn, tuber, and rhizomes. These plants have economic value especially in ornamental plant sector as cut flower, potted flower, and outdoor plants. Most of these plants have garish flower, and many of them are monocotyledon. Cyclamen, Tulipa, Lilium, Narcissus, Gladiolus, Hyacinthus, Crocus, Iris, Allium, Alstroemeria, Anemone, Orchis, Rhododendron, Freesia, Hippeastrum, Muscari, Ornithogalum, Ranunculus, and Zantedeschia are the most important geophytes that are commercially used in the world. These plants can be propagated using conventional and tissue culture techniques. Synthetic seed production is one of these techniques. Synthetic seed, namely, artificial seed, is described as artificially encapsulated plant tissues and somatic embryos with alginate hydrogel. Synthetic seed technology has significant effect on the conservation of the plant tissues and sustainability of the plants. Recently, conservation of the plant species studies significantly increased, and artificial seed method was used as the most common process to conserve important species. in this chapter, oldest and newest synthetic seed production researches were discussed and presented chronologically
In vitro propagation and germplasm conservation of wild orchids from South America
Orchids are an important part of plant biodiversity on this planet due to their high variability among species and their habitats. South America represents more than thirty percent of all known orchid species, Colombia, Ecuador, Brazil, Peru, and Bolivia being among the richest countries in the world in terms of orchid biodiversity. Nevertheless, concerning the orchid conservation status, in Colombia precisely orchids occupy the unlucky first place as the plant family with the highest number of threatened species. There is a similar situation in the rest of the South American countries. The two main threats to orchid survival are both anthropogenic: the first one is deforestation, and the second largest threat to orchids is collection from the wild. One desirable action to safeguard these endangered species is to develop procedures that make possible their massive propagation, which would provide material for both environmental restoration and commercial purposes avoiding extractions from nature. Likewise, the development of systems that allow the ex situ conservation of orchid germplasm is imperative. This chapter reviews the progresses of different in vitro approaches for orchid propagation and germplasm conservation, safeguarding the genetic biodiversity of these species. Several study cases are presented and described to exemplify the protocols developed in the Botanical Institute of Northeast (UNNE-CONICET) for propagating and long-term storing the germplasm of wild orchids from Argentina (Cattleya lundii, Cohniella cepula, C. jonesiana, Gomesa bifolia, Aa achalensis, Cyrtopodium brandonianum, C. hatschbachii, Habenaria bractescens). Moreover, it has been attempted to put together most of the available literature on in vitro propagation and germplasm conservation for South American orchids using different explants and procedures. There are researches of good scientific quality that even cover critical insights into the physiology and factors affecting growth and development as well as storage of several orchid materials. Moreover, studies are still necessary to cover a major number of South American species as well as the use of selected material (clonal) for both propagation and conservation approaches.Fil: Dolce, Natalia Raquel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Medina, Ricardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: Terada, Graciela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; ArgentinaFil: González Arnao, María Teresa. Universidad Veracruzana; MéxicoFil: Flachsland, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Nordeste. Instituto de Botánica del Nordeste. Universidad Nacional del Nordeste. Facultad de Ciencias Agrarias. Instituto de Botánica del Nordeste; Argentin