| 1. |
- Helmersson, Andreas, et al.
(författare)
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Embryogenic cell lines of Juniperus communis, easy establishment and embryo maturation, limited germination
- 2009
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Ingår i: Plant Cell, Tissue and Organ Culture. - : Springer Science and Business Media LLC. - 0167-6857 .- 1573-5044. ; 96, s. 211-217
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Tidskriftsartikel (refereegranskat)abstract
- Several coniferous species belonging to the Pinaceae family can be propagated via somatic embryogenesis, while species belonging to the Cupressaceae family cannot. The aim of this study was to identify possibilities and limitations with somatic embryogenesis in Cupressaceae. Juniperus communis was chosen as model species. We show that a high initiation frequency of embryogenic cell lines can be established from intact megagametophytes at the time when intensive cleavage polyembryogeny takes place. The embryogenic cell lines proliferate fast on medium lacking plant growth regulators. Early somatic embryos develop after transfer to medium with decreased content of nitrogen and calcium. The early embryos mature after exposure to abscisic acid. Mature cotyledonary embryos germinate after partial desiccation. A high proportion, over 40%, of the germinating embryos retain the embryogenic potential in the basal part, resulting in development of new embryogenic tissue
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| 2. |
- Sriskandarajah, Sridevy, et al.
(författare)
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High frequency shoot organogenesis and somatic embryogenesis in juvenile and adult tissues of seabuckthorn (Hippophae rhamnoides L.)
- 2009
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Ingår i: Plant Cell, Tissue and Organ Culture. - : Springer Science and Business Media LLC. - 0167-6857 .- 1573-5044. ; 99, s. 259–268-
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Tidskriftsartikel (refereegranskat)abstract
- Seabuckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values. A clonally propagated plant originating from a 20-year-old tree of H. r. rhamno- ides 9 mongolica hybrid cultivar Julia and seedling offspring of this cultivar were investigated regarding induction of shoot organogenesis in leaf explants and in roots of intact seedlings, and induction of direct somatic embryogenesis in explants from shoot tissue. The highest percentage of leaf explants showing shoot organogenesis was achieved (juvenile explants, 65%; adult explants, 75%) when incubated in Mu- rashige and Skoog (MS) medium supplemented with either 4.5 lM of the phenylurea cytokinin thidiazuron (TDZ) or 2.25 lM TDZ plus 2.2 lM 6-benzyladenine (BA), for juve- nile and adult explants, respectively, both supplemented with 0.53 lM a-naphthaleneacetic acid (NAA). Juvenile explants developed on average 18 shoots per explant in the MS med- ium supplemented with 4.5 lM TDZ, a four fold increase over those incubated on the medium supplemented with 2.25 lM TDZ and 2.2 lM BA. Adult leaf explants grown on medium containing 2.25 lM TDZ and 2.2 lM BA medium produced 12 shoots per explant, while those grown on med- ium containing 4.5 lM TDZ produced 5 shoots per explant. Shoot organogenesis was observed in roots of intact seedlings pre-cultured on plain medium lacking nutrients (PM) or woody plant medium (WPM) salts and then grown on WPM salts supplemented with 4.4 lM BA, 0.29 lM gibberrelic acid (GA3), and 57.0 lM indoleacetic acid (IAA). The number of shoots formed on each seedling root system was ten fold higher when the pre-culture was in WPM medium indi- cating a promoting effect of mineral nutrients in the pre-cul- ture medium. Somatic embryogenesis was induced in both juvenile and adult leaf explants in 65 and 78% of the explants, respectively, in MS-based medium supplemented with 2.0 lM N-(2-Chloro-4-pyridyl)-N1-phenylurea (CPPU), 0.53 lM NAA and varying concentrations of BA. There was an interaction effect between MS salt strength and BA con- centration. The most effective medium for inducing somatic embryogenesis in juvenile explants contained half strength MS salts and 2.2 lM BA and full strength MS salts and 13.2 lM BA for adult explants
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