Efficient plant regeneration from embryogenic cell suspension cultures of Euonymus alatus

To establish an efficient plant regeneration system from cell suspension cultures of Euonymus alatus, embryogenic callus formation from immature embryos was investigated. The highest frequency of embryogenic callus formation reached 50% when the immature zygotic embryos were incubated on Murashige and Skoog (MS) medium supplemented with 1 mg/L 2,4-dichlorophenoxy acetic acid (2,4-D). At higher concentrations of 2,4-D (over 2 mg/L), the frequency of embryogenic callus formation declined significantly. The total number of somatic embryos development was highest with the 3% (w/v) sucrose treatment, which was found to be the optimal concentration for somatic embryo formation. Activated charcoal (AC) and 6-benzyladenine (BA) significantly increased the frequency of plantlet conversion from somatic embryos, but gibberellic acid (GA3) had a negative effect on plantlet conversion and subsequent development from somatic embryos. Even though the cell suspension cultures were maintained for more than 1 year, cell aggregates from embryogenic cell suspension cultures were successfully converted into normal somatic embryos with two cotyledons. To our knowledge, this is the first successful report of a plant regeneration system of E. alatus via somatic embryogenesis. Thus, the embryogenic cell line and plant regeneration system established in this study can be applied to mass proliferation and production of pharmaceutical metabolite in E. alatus.

The evaluation of java fine flavor cocoa propagation through somatic embryogenesis technique for germplasm preservation

Somatic embryogenesis is one of the newest technology that applied for the mass production of cocoa. This research aims to evaluate the regeneration rate of somatic embryos through somatic embryogenesis propagation techniques on java fine flavor cocoa. Cultivars in this study are ICCRI 01, ICCRI 02, DR 1, DR 2, DRC 16, DR 38, PNT 16, and PNT 30. Observations include parameters to determine the percentage of primary callus and embryogenic callus formation and the number of somatic embryos produced. Based on data, the ability of callus to produce primary embryos is highly dependent on plant cultivars and explant sources. Five cultivars showed a higher regeneration rate using explants from the petal part, while the rest showed a higher regeneration rate using explants from the staminode section. Embryogenic callus from each cacao cultivar has the same basic structure: a nodular friable structure consisting of many embryonic cells. Some fine flavor cacao cultivars that were able to produce callus and primary somatic embryos could not produce secondary somatic embryos and plantlets. However, two cultivars, which had low potential in producing primary embryos, had the high ability to produce secondary somatic embryos and develop into plantlets.

Cryopreservation of Brazilian green dwarf coconut plumules by droplet-vitrification

ABSTRACT: This study evaluated the effect of vitrification solutions and exposure time on the cryopreservation of Brazilian green dwarf coconut plumules (BGD) using the droplet vitrification technique. Explants were excised from BGD mature fruits from the Active Germplasm Bank of Embrapa Tabuleiros Costeiros, Sergipe, Brazil. Firstly, embryos were disinfected, and after excision, plumules were pre-cultivated for 72 hours in Y3 + 0.6 M sucrose + 2.2 g L-1 Gelrite® culture medium. Plumules were exposed to PVS2 and PVS3 solutions for 15 and 30 minutes and rapidly immersed in liquid nitrogen (-196 ºC). After cryopreservation, they were thawed in culture medium solution (Y3 + 1.2 M sucrose) and cultured in regeneration medium. The experimental design was completely randomized in a 2x2 factorial scheme (vitrification solutions per exposure times), with five replicates per treatment. Data were compared by the Tukey’s test at 5% probability. Significant differences were observed in the callogenesis percentage for the solutions x exposure time interaction for non-cryopreserved cultures (-NL) and for exposure time after cryopreservation (+NL). PVS2 and PVS3 combined with 15 minutes of exposure promoted the highest callus formation (70 and 100%, respectively) in control cultures. The exposure time of 30 min, regardless of vitrification solution, resulted in 30% embryogenic callus formation after cryopreservation. These results contributed to the long-term conservation of coconut palm.

Studies on In Vitro Response to Callus Induction and Regeneration of Five High Yielding Indica rice Varieties

Due to growing population, there is an increasing demand of rice production but the productivity of rice is lessened day by day. To overcome this problem various biotechnological tools can be used for developing various rice varieties. However, the lack of a simple and efficient protocol for callus induction, embryogenic callus formation and quick plant regeneration in this cereal crop. In this study embryogenic calli from mature seeds of five indica rice varieties viz. Binadhan-5, Binadhan-6, BRRI dhan-48, BRRI dhan-58 and IR-64 were observed that is done in four different types of media composition. The highest callus induction were observed in media containing Sucrose as a carbon source. Among those varieties Binadhan-6 and BRRI dhan-48 showed highest rate of callus induction respectively. This study will be useful for selecting suitable callus induction medium for callus induction in future that will be useful for not only national but also international plant breeders for producing new variety and so on.

Induction of somatic embryogenesis in two cultivars of anthurium analysed by scanning electron microscopy

Somatic embryogenesis is an advantageous tool in the commercial production of micropropagated anthurium plantlets. As such, the aim of this study was to establish a protocol for the induction of somatic embryogenesis in Jureia and Luau cultivars. Defoliated nodal segments, 1.0 cm in length and containing one bud, were used as explants. The experimental design was completely randomised, in a 2 x 3 x 5 factorial scheme (cultivar: Jureia and Luau x auxin: 2,4-D, NAA and Picloram x concentration: 0, 2.5, 5.0, 7.5, and 10.0 μM), with 30 treatments in a scheme of plots split over time (15, 30, 45, 60, 75 and 90 days). The anatomy and percentage of embryogenic callus formation were analysed. The structures formed, analysed by scanning electron microscopy, corresponded to embryogenic calli. The Luau cultivar was superior in forming embryogenic calli. For the two cultivars, among the auxins under study, NAA demonstrated a greater induction potential for somatic embryogenesis, with the concentration of 7.5 μM giving the highest mean values. The 90-day evaluation period showed the maximum formation of embryogenic calli; however, mean values were fairly similar to the 75-day evaluation period. To induce embryogenic calli, therefore, it is suggested that the nodal segments be inoculated into a culture medium with added NAA growth regulator at a concentration of 7.5 μM, and that the explants remain in this medium for 75 days after inoculation.

Somatic Embryo from Basal Leaf Segments of Vanda tricolor Lindl. var. pallida

<p class="Els-Abstract-text">Somatic embryogenesis is one of techniques in plant micropropagation. The induction of somatic embryogenesis through callus phase was done on <em>Vanda tricolor</em> Lindl. var. pallida. This study aimed to find out the effect of naphtalene acetic acid (NAA) and benzyl amino purine (BAP) in inducing somatic embryogenesis via callus on the basal leaf segments of <em>Vanda tricolor</em> Lindl. var. pallida. The half-strength of Murashige and Skoog (½ MS) medium with 1 % sucrose, incorporated with (0.02 mg · L^–1and 0.05 mg · L^–1) NAA and also 0.01 mg · L^–1 BAP were used in this experiment. The best medium for embryogenic callus formation and proliferation was 0.05 mg · L^–1 NAA in combination with 0.01 mg · L^–1 BAP. The formation of somatic embryos occurred 30 d after the calluses were cultured on to ½ MS without the addition of plant growth regulator and subsequently formed shoots.</p>

High embryogenic ability and regeneration from floral axis of Amorphophallus konjac (Araceae)

Amorphophallus konjac (Araceae) a perennial herb, it has high medicinal and industrial value. In this study, a simple and efficient system for direct somatic embryogenesis and plantlet regeneration of Amorphophallus konjac was developed. The floral axis was used as the experimental material. The primary callus, developed from the floral axis grown on Murashige and Skoog (MS) medium supplemented with different hormone combination at different concentrations. The highest rate of embryogenic callus formation was observed on the MS medium containing 9.04 µM 2, 4-dichlorophenoxyacetic acid (2, 4-D) and 5.37 µM naphthalene acetic acid (NAA). The maximum induction rate was 79.8%, and the embryogenic calli were able to subculture on a medium containing similar hormone combination for over 1 year. The calli were also placed on different media for regeneration and it produced complete plants with shoots and root systems simultaneously. The highest differentiation rate of the embryogenic calli grown on differentiation medium supplemented with 8.88 µM 6-benzylaminopurine (6-BA) and 5.37 µM NAA was 95.6%. Flow cytometry analysis showed no ploidy variation in all the regenerate plantlets.