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Open access

Jaime A. Teixeira da Silva

Abstract

High frequency protocorm-like body (PLB) production from hybrid Cymbidium Twilight Moon ‘Day Light’ has been developed through a new medium, Teixeira Cymbidium (TC) medium. Two new TC media containing variable amounts of macroand micronutrients and other additives, inspired by Winarto and Teixeira (WT) medium for Anthurium and Murashige and Skoog (MS) basal medium were used to induce PLBs and callus. Control medium was research- and industry-standard Vacin and Went (VW) medium. The first TC medium, TCPLB, could induce significantly more PLBs than on VW while high levels of macronutrients in the second TC medium, TCCALLUS, and MS were required to induce callus. All PLB induction media contained 0.1 mg/l α-naphthaleneacetic acid (NAA) and 0.1 mg/l kinetin (KIN), 2 g/l tryptone and 20 g/l sucrose, and solidified with 8 g/l Bacto agar while callusinduction media were identical, except that KIN was substituted by thidiazuron (TDZ). Basal medium had a significant effect on PLB and callus formation. This protocol could be used to induce PLBs and callus from other Cymbidium species or cultivars.

Open access

Jaime A. Teixeira da Silva

Abstract

The Committee on Publication Ethics (COPE) is the largest ethics-related body in the world. However, the lack of clear policy related to the ethics of self-plagiarism, its stated inability to intervene in ethics-related conflicts involving several of its members causing a relative lack of opacity when authors wish to communicate concerns with or about a COPE member, inconsistent use of ethics guidelines by all its members, and the inability to call out its members when these may appear to be violating COPE editorial guidelines all contribute to the decrease in trust that authors - who are clearly not represented by the COPE charter - have in this organization and its members. One of the key corrupting factors is money. COPE members pay annual fees to become members, but only editors and publishers can become members. Consequently authors′ rights and concerns about COPE members are rarely addressed. Authors, who already have minimal rights in the entire publishing process, and very limited recourse for self-defense or protest, are considerably marginalized should conflicts with a COPE member exist. How then, can authors and the public hold COPE members more accountable?

Open access

Jaime A. Teixeira da Silva

Abstract

Synthetic seed were produced from protocorm-like bodies (PLBs) of hybrid Cymbidium Twilight Moon ‘Day Light’ after culture on a new medium, Teixeira Cymbidium (TC) medium. This new medium contained, in addition to a unique selection of macro- and micronutrients, 0.1 mg/l α-naphthaleneacetic acid and 0.1 mg/l kinetin, 2 g/l tryptone and 20 g/l sucrose, and was solidified with 8 g/l Bacto agar. Several explant types and sizes (intact PLBs, half-PLBs, PLB longitudinal thin cell layers) were tested. In addition, pretreatment of PLB-synseeds with 200 mM KNO3 solution, the addition of activated charcoal or coconut water to synseeds, light vs dark culture, short-term (1 month) and long-term (6 and 12 months) low-temperature (4°C) storage, as well as cryostorage were also tested. All treatments resulted in less PLBs than the control treatment. Among all these treatments, only the use of TC medium or incorporation of coconut water into synseeds resulted in “germination” while lowtemperature storage (1-6 months) was only possible under liquid TC. These results would allow for the short-term preservation of Cymbidium germplasm but not for effective cryopreservation.

Open access

Jaime A. Teixeira Da Silva

Abstract

Teixeira da Silva J.A., 2014: Response of hybrid Cymbidium (Orchidaceae) protocorm-like bodies to 26 plant growth regulators [Cymbidium (Orchidaceae) hibrido į protokormą panašių kūnelių reakcija į 26 augalų augimo reguliatorius]. - Bot. Lith., 20(1): 3-13.

Plant growth regulators (PGRs) are one of the most effective means of controlling plant organogenesis in vitro. Hybrid orchid production relies on effective protocols to maximize clonal shoot output. This is best achieved when protocormlike bodies (PLBs) are propagated. In a bid to deepen orchidologists’ understanding of basic responses of Cymbidium to PGRs, this study aimed to establish the organogenic response of hybrid Cymbidium Twilight Moon ‘Day Light’ half-PLBs or PLB thin cell layers (TCLs) to a single application of PGRs (6 auxins; 7 cytokinins; 3 alternative PGRs), 3 herbicides or 7 growth inhibitors/retardants at 4 concentrations (1, 2, 4 or 8 mg·1-1) as well as a control (0 mg·1-1), both in the light and in the dark. The control (PGR-containing TC medium) performed best, but all auxins and growth inhibitors and retardants were toxic to neo-PLB formation, resulting in 100% death. A synthetic auxin (BSAA), a cytokinin (4-CPPU) and two herbicides (dicamba and picloram) were equally toxic. No auxins, TIBA, GA3 or SA induced any organogenic response. 1 or 2 mg·1-1 2,4-D or 1 mg·1-1 TDZ induced embryogenic callus, but 2-8 mg·1-1 2,4-D resulted in abnormal shoots. TDZ induced direct multiple shoots. Only five remaining cytokinins (Ads, BA, Kin, ZR, 2iP) could form neo-PLBs, but always significantly less than the controls, independent of the explant used (half- PLBs or tTCLs) and light conditions (light vs darkness). These five cytokinins could be useful for neo-PLB induction of other Cymbidium hybrids. A new concept, the average cumulative value or ACV, is introduced

Open access

Jaime A. Teixeira da Silva

ABSTRACT

The mid- to long-term preservation of papaya (Carica papaya L.) would allow for the safeguarding of important germplasm. In this study, soft friable callus (SFC) and hard callus (HC) were induced from the first two true leaves of 10-day-old seedlings containing a midrib derived from the germinated seed of two cultivars (‘Rainbow’ and ‘Sunrise Solo’). Following germination on a Murashige and Skoog (MS) medium that contained 3% sucrose and was free of plant growth regulators (PGRs), sections of the first true leaves from 10-day-old seedlings were exposed to seven published callus or somatic embryogenesis protocols for zygotic embryos, leaves or hypocotyls. Optimal SFC and HC induction was carried out on a half-strength MS medium following the Fitch (1993) or the Ascêncio-Cabral et al. (2008) protocol, respectively. SFC formed shoots that could then convert to plants when transferred to a full-strength MS medium devoid of PGRs. Plantlets 10-cm tall were acclimatised in two steps: first by in vitro acclimatisation in aerated vessels, the Vitron, under CO2-enriched (3000 ppm CO2), then by the transfer of individually rooted plantlets in Rockwool® blocks to a substrate of soil: pine bark : perlite (1:1:1, v/v/v). SFC and HC were then encapsulated in alginate beads, which were exposed to low temperature storage (LTS) at 10°C and 15°C, and also cryopreserved for 30 days. All encapsulated alginate beads that contained SFC, HC or leaf tissue that had been stored under LTS or cryopreserved were able to regenerate callus when placed on an optimal callus induction medium. Plants derived from the control, LTS and cryopreservation protocols, either from SFC or HC, were successfully acclimatised.

Open access

JAIME A. TEIXEIRA DA SILVA

Abstract

Only few studies in the plant tissue culture literature have examined the impact of filter paper on in vitro plant organogenesis. In this study, using a model plant, hybrid Cymbidium Twilight Moon ‘Day Light’, the impact of a single or double layer of Advantec #2 or Whatman #1 filter paper on new protocorm-like body (neo-PLB) formation on Teixeira Cymbidium (TC) medium was examined for half-PLBs (transgenic and non-transgenic), PLB-derived transverse thin cell layers (tTCLs), and PLB synseeds. In addition, the response of half-PLBs or tTCLs to two antibiotics (kanamycin and cefotaxime, commonly used in plant genetic transformation studies) was investigated either directly on gelled medium or on filter paper-overlaid medium. Filter paper negatively affected most growth and developmental parameters of all the explants tested, both transgenic and non-transgenic. A double sheet of filter paper had a significantly (P ≤ 0.05) more negative impact than a single sheet, relative to the control values (i.e., no filter paper). Kanamycin inhibited neo-PLB formation on TC medium, the negative impact being greater on a single layer than on a double layer of filter paper, i.e., filter paper buffered the growth-inhibiting characteristics of kanamycin. Up to 100 mg/l, cefotaxime showed no apparent negative effects on neo-PLBs formation and growth, although hyperhydricity was observed when filter paper was not used.

Open access

Jaime A. Teixeira Da Silva

Abstract

Teixeira da Silva J.A., 2014: Novel factors affecting shoot culture of chrysanthemum (Dendranthema × grandiflora) [Alternatyvių standiklių, skystų terpės priedų, CO2 sodrinimo ir kitų faktorių įtaka chrizantemų (Dendranthema × grandiflora (Ramat.) Kitamura) ūglių kultūrų auginimui]. - Bot. Lith., 20(1): 27-40.

Chrysanthemum (Dendranthema × grandiflora (Ramat.) Kitamura) continues to be one of the most important ornamental plants in the world. Although the tissue culture of chrysanthemum has been widely explored, several unexplored topics remain, and, in developing countries, there is always the constant search for reducing the cost of raising tissue cultured plants. In this study, by focusing on a leading market cultivar in Japan, ‘Shuhouno- chikara’, alternatives to agar (as the gelling agent) and sucrose (as the carbon source) for chrysanthemum tissue culture were sought. Both Gellan gum and agar resulted in greater shoot and root production than all other gelling agents tested, including Bacto agar, phytagel, oatmeal agar, potato dextrose agar, barley starch and corn starch. All of the alternative liquid-based medium additives tested (low and full fat milk, Coca-cola ®, coffee, Japanese green, Oolong and Darjeeling teas) negatively impacted plant growth, stunted roots and decreased chlorophyll content (SPAD value) of leaves. There was no difference between plants grown on medium with refined sucrose or table sugar, although poor growth was observed when stevia (Stevia rebaudiana) extract was used. Photoautotrophic micropropagation increased significantly the shoot mass relative to control plants, even when the density of plants was doubled. Aeration improved plantlet growth. The tetrazolium test was a simple, but effective essay to see the intensity and strength of root growth in different basal media. MDH activity decreased in the root+shoot extract of plants grown on most alternative media, but remained high on TCSGM (Teixeira’s chrysanthemum shoot growth medium), Gellan gum, aerated and CO2-enriched cultures. A similar trend was observed for deaminating GDH, while an opposite trend was observed for aminating GDH activity. These experiments indicate that tissue culture research for chrysanthemum still provides a rich field for exploration with interesting and valuable results

Open access

Jaime A. Teixeira da Silva and Vedran Katavić

Abstract

In this opinion piece, some of the practices of academic publication in the biomedical field related to the rewarding, or the lack thereof, of peer reviewers are described and discussed. The role and possibly exploitative relationship of mainstream, established publishers of prestigious journals towards their contributors (authors), and peer reviewers is considered. In addition, the role and accountability of publishers and contributors in “predatory” journals is assessed. Professionals who are recruited by the publishing industry, especially the for-profit industry, either as peer reviewers or editors, to complete a professional task, should be rewarded financially as professionals, as for other sectors of the economy, and not simply exploited for free. Points systems or discounts off a publisher’s products do not constitute sufficient, or fair, compensation.

Open access

Jaime A. Teixeira da Silva

Abstract

The author surveyed the instructions for authors in 110 botanical journals to assess how widely italic is used to represent the Latin binomial names of plants. Except for one journal that eliminated italic from the reference list, all of these journals published articles that used italic in the text and reference list for Latin binomial names of plants. However, in their instructions for authors only 48% of these journals explicitly requested the use of italic to denote the Latin binomial names of plants.

Open access

Jaime A. Teixeira da Silva

Abstract

ResearchGate (RG) is one of the most popular academic social media platforms currently available to scientists. Allowing scientists, researchers and academics (SRAs) to network through the creation of a free account. RG provides a virtually unlimited ability for SRAs to share research, contact each other through an integrated platform and share ideas. In recent times, projects have been increasing in scope and visibility, fortifying the RG network status. This paper examines some of the project-related features at RG and points out, within a wider examination of RG and other SRA-oriented academic social media platforms, the existing benefits and risks. The results of this work will allow SRAs to manage and invest their time in a better way.