Picloram-induced enhanced callus-mediated regeneration, acclimatization, and genetic clonality assessment of gerbera

Background Gerbera jamesonii Bolus ex Hooker f. (African daisy) is listed among the top five most important ornamental plants in the global floricultural industry. To satisfy its demand, the floriculture industry relies on reproducible and effective propagation protocol while retaining the genetic uniformity of G. jamesonii. The present study, for the first time, reports the potential of picloram for enhanced induction of organogenic calli from leaves of G. jamesonii and its high-frequency indirect regeneration. Results The fastest induction of calli with maximum fresh and dry weight was recorded in the Murashige and Skoog (MS) semisolid medium supplemented with 1 mg/l picloram. In addition, callus induction was observed in 2,4-dichlorophenoxy acetic acid- and α-napthaleneaceticacid-supplemented media but with delayed response and reduced fresh and dry weight. The proliferated calli were transferred to shoot induction media containing MS salt and 0.5–1 mg/l N6-benzylaminopurine, kinetin, or thidiazuron. A mean number of ~6 shoots per callus were developed after 5 days of culture in the MS medium supplemented with 1 mg/l kinetin, with a mean length of 5.2 cm. Successful rooting of shoots was achieved in the MS medium fortified with 1.5 mg/l indole-3-acetic acid, wherein the earliest root initiation (~5 days), as well as the maximum number (~9) and length (~4.8 cm) of roots, were recorded. Complete plantlets were primarily acclimatized in sand before being transferred to a mixed substrate (of soil, sand, tea leaf waste, and cow urine) that secured >90% survival and further growth of the plantlets. Eventually, clonal fidelity of the in vitro regenerants assessed via inter-simple sequence repeats (ISSR) primers exhibited a monomorphic banding patterns that suggested genetic integrity within the plantlets as well as with their mother plant. Conclusions The results of the present study should be of interest for commercial propagation and mutagenesis- as well as genetic transformation-related research.

Effect of 2,4-Dichlorophenoxy Acetic Acid and Activated Charcoal on Callus Induction of Cocos Nucifera L. Hybrid MATAG Inflorescence

Cocos Nucifera Linn. Var. MATAG is a Dwarf coconut variety that had high demand in Malaysia but low supply. Vegetative propagation of high-yielding MATAG coconut by using in vitro cloning must be considered in contributing to increase coconut productivity. Thus, attempts were made to develop a protocol that would enhance callogenesis as a first preliminary step towards a protocol for mass propagation of C. nucifera L. var. MATAG. The anther isolated from immature inflorescence was used as explants and cultured on modified Eeuwens Y3 media in different concentrations of 2,4-dicholorophenoxy acetic acid (2,4-D) and activated charcoal. The highest callus induction percentage (31.25 ± 12.18) was observed in 20 mg/L 2,4-D. However, 2,4-D at any level tested were not statistically significant. Callus induction media supplemented with 0.5 mg/L activated charcoal gave the highest callusing percentage (25.89 ± 13.59 %) indicating a positive effect of activated charcoal on callusing even though the result obtained not significant compared to control (15.95 ± 6.76 %). But, activated charcoal supplemented in media produced a significant effect compared to control in reducing the percentage of browning. In conclusion, media supplemented with activated charcoal produced a higher rate on callus induction and preventing tissue browning in explant. Besides that, the anther and ovule explant may serve as an efficient explant to study the callus induction of C. nucifera L. var. MATAG and as a basis to screen the potential useful plant growth regulators for somatic embryogenesis.

Effects of the growth regulators for the induction of somatic embryos from explants in an endemic and threatened Echinocactus parryi Engelm.

Introduction: The list of threatened species is enhancing and needs to be revised by integrating plant tissue culture tools with conventional techniques that support the appropriate management of these species. Objective: To assess the effects of the growth regulators for the induction of somatic embryos from mature seeds, shoots, and compact green callus of Echinocactus parryi Engelm. and the histological analysis of the embryogenic structures. Materials and methods: A completely randomized design was utilized to evaluate three types of explants (apical, medium, and basal) cultured on basal Murashige & Skoog media (MS) with different growth regulators concentrations (2, 4-D [dichlorophenoxy acetic acid], BAP [6-benzylaminopurine] and kinetin, at four levels: 0.5, 1, 1.5, and 2 mg∙L -1 ). Histological analysis of the embryogenic structures was performed. Results and discussion: The 2, 4-D induced both embryogenic and organogenic callus from seeds and shoot explants. The globular stage did not evolve to their maturity, presumably because of 2, 4-D accumulation. The compact callus explants were the more efficient to induce 19.2 somatic embryos per explant when they were cultured in the medium with 0.5 mg∙L -1 kinetin. However, the latest phases did not germinate, probably due to abnormalities generated by genetic and epigenetic changes in the DNA that can cause abnormal somatic embryos. The histology image demonstrated that the globular and torpedo structures were visible under a microscope showing stained nucleus and numerous starch grains. Conclusions: E. parryi is a species that can produce a high number of embryogenic structures, which represents a great potential to grow massive plants.

Synthesis of Hybrid Organic-Inorganic Hydrotalcite-Like Materials Intercalated with Duplex Herbicides: The Characterization and Simultaneous Release Properties

In this study, a controlled-release formulation of duplex herbicides, namely, 2,4,5-trichlorophenoxybutyric acid (TBA) and 3,4-dichlorophenoxy-acetic acid (3,4D), was simultaneously embedded into Zn-Al-layered double hydroxides (LDHs). The resulting nanohybrid Zinc-Aluminium-3,4D-TBA (ZADTX) was composed of a well-ordered crystalline layered structure with increasing basal spacing from 8.9 Å to 20.0 Å in the Powder X-ray Diffraction (PXRD) with 3,4D and TBA anions located in the gallery of LDHs with bilayer arrangement. The release of 3,4D and TBA fit the pseudo-second-order model. This duplex nanohybrid possessed a well-controlled release property (53.4% release from TBA and 27.8% release from 3,4D), which was highly effective, requiring the use of a small quantity and, hence, environmentally safer.

Sterile Tissue Preparation and Callus Induction of Curcuma longa Linn.

Curcuma longa Linn. (family Zingiberaceae), commonly known as ‘turmeric’, is native to Southeast Asia. Turmeric has been used for color, flavor as a spice in cuisine and employed for treatment of various diseases. The major component in yellow-pigmented fraction of turmeric is curcuminoids. Curcuminoid production in callus of C. longa Linn. is our focus of study. Sterile techniques to obtain germ-free of C. longa Linn. explants were investigated and the results showed that immersing rhizome buds in 70% ethanol for 5 min, followed by 0.10% HgCl2 for 10 min offered approximately 66% survival rate. Multiple shoots were generated from the aseptic rhizome explants cultured on Murashige and Skoog (MS) agar medium fortified with 3.00 µM of 6-Benzylaminopurine (BA) and 0.50 µM of 1-Naphthaleneacetic acid (NAA) at 25 ± 2°C under a photoperiod of 16 h light and 8 h dark. The sterile leaf sheath and root were subsequently used for callus induction which produced various responses when cultured on MS agar medium fortified with different concentrations of 2,4-dichlorophenoxy acetic acid (2, 4-D), Thidiazuron (TDZ) and BA. The highest induction yields of friable callus were obtained from leaf sheath segments cultured on MS agar medium fortified with 0.50 mg/l 2, 4-D which are the conditions proposed for successful production of callus culture of C. longa Linn. Keywords: Callus induction, Curcuma longa Linn., Turmeric, Plant tissue culture

High-Frequency Shoot Regeneration From Flower Bud Derived Callus of Gymnostachyum Febrifugum Benth., an Endemic Medicinal Plant to the Western Ghats

Gymnostachyum febrifugum Benth. is a small, scapigerous, rare and endemic medicinal herb indigenous to India belonging to the family Acanthaceae. This study reports an efficient protocol for high-frequency flower bud derived callus induction and shoot organogenesis in G. febrifugum. Flower buds at 7d before anthesis (dBA) were excised from the inflorescence and cultured on MS medium supplemented with various concentrations of 2, 4-dichlorophenoxy acetic acid (2, 4-D; 0.5-2.0 mg/l) for callus induction. The optimum callus induction (78%) was obtained on MS medium supplemented with 1.5 mg/l 2, 4-D. The calli when subcultured on MS medium supplemented with different concentrations of thidiazuron (TDZ; 0.5-2.5 mg/l) or 6-benzylaminopurine BAP (0.5-2.5 mg/l) alone or in combination with 1- naphthaleneacetic acid (NAA; 0.2-0.7 mg/l) induced shoots. The highest frequency (94%) and number of shoots (44.6 shoots/unit callus) were obtained on MS medium supplemented with 2.0 mg/l TDZ and 0.5 mg/l NAA. The optimum rooting frequency (95%) and number of roots (10.2) were observed on ½ MS medium supplemented with 3.0 mg/l indole-3- butyric acid (IBA). The rooted plantlets were acclimatized and transferred to soil with 94% success.

Synthesis of a plasmonic AgCl and oxygen-rich Bi24O31Cl10 composite heterogeneous catalyst for enhanced degradation of tetracycline and 2,4-dichlorophenoxy acetic acid

Photocatalytic degradation of tetracycline and 2,4-dichlorophenoxy acetic acid using AgCl/Bi24O31Cl10 photocatalyst in visible light.