English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The present study reports a simple protocol for in vitro regeneration of Aglaonema ‘Valentine’ using axillary shoot explants for rapid multiplication and production of true-to-type plants. Different concentrations of benzyladenine (BA; 0, 1, 3, 5, and 7 mg·L), kinetin (Kin; 0, 1, 3, 5, and 7 mg·L), thidiazuron (TDZ; 0, 0.5, 1.0, 1.5, and 2.0 mg·L), naphthalene acetic acid (NAA; 0, 0.5, and 1.0 mg·L), and indole3-butyric acid (IBA; 0, 0.5, and 1.0 mg·L) were used for shoot regeneration. The highest shoot proliferation (5.0) was obtained on Murashige and Skoog (MS) medium supplemented with 1.5 mg·L TDZ and 1 mg·L NAA. In vitro rooting was easily achieved with 100% at all concentrations of NAA and IBA supplemented to halfor fullstrengthMSmedium. Regenerated plantlets were acclimatized in greenhouse with 100% survival rate. Randomly amplified polymorphic DNA (RAPD) analysis confirmed the genetic fidelity of the regenerated plantlets and mother plant. Aglaonema, Araceae, is one of the most important ornamental foliage plant genera due to its attractive foliar variegation and tolerance to low light conditions (Chen et al., 2002). The genus has 23 species that are herbaceous evergreens native to tropical and subtropical regions of southeast Asia, northeastern India, across southern China, and into Indonesia and NewGuinea (Govaerts and Frodin, 2002; Kew Garden, 2015). ‘Valentine’ is a new attractive hybrid from Thailand with beautiful pink and green random blotches. Commercial Aglaonema propagation almost exclusively starts from cuttings and by dividing the basal shoots. However, traditional propagation using cuttings sometimes transmits pathogens such as fungal, bacterial and viral diseases from stock plants to cuttings (Chase, 1987). In addition, some Aglaonema cultivars may host endogenous pathogens in their vascular tissue (Chase, 1997), which could make cuttings a source for carrying and spreading diseases. Subsequently, tissue culture is considered the best method to get stock aroids free from endogenous contaminations (Elsheikh et al., 2013; Taylor and Knauss, 1978). In vitro propagation methods are used for production of ornamental plants to meet the growing demand in both the domestic and the export market. So, the use of tissue culture technique in vegetatively propagated Aglaonema is an alternative method to obtain rapid clonal multiplication. However, the difficulty of establishing or maintaining aseptic culture (Chen and Yeh, 2007) and low rate of shoot multiplication (Chen and Yeh, 2007; Zhang et al., 2004) are definite factors in tissue culture of Aglaonema plant. The previous studies showed that average shoot number depends on the cultivar and protocol (Chen and Yeh, 2007; Fang et al., 2013; Mariani et al., 2011; Zhang et al., 2004). Aglaonema ‘Valentine’ is slow growing in greenhouse and has a low rate of shoot multiplication in tissue culture. Plant growth regulators (PGRs), especially cytokinins, are crucial for shoot multiplication in aroids including Aglaonema (Chen and Yeh, 2007),Dieffenbachia maculata (G. Lodd.) and Dieffenbachia amoena WB (Elmahrouk et al., 2006), and Spathiphyllum cannifolium Engl. (Dewir et al., 2006). In vitro plant propagation methods have been developed for some Aglaonema cultivars, including White Tip (Chen and Yeh, 2007), Cochin (Mariani et al., 2011), and Lady Valentine (Fang et al., 2013). However, previous reports on the micropropagation of Aglaonema did not determine the homogeneity among the regenerated plantlets. In recent years, clonal fidelity assessment of the micropropagated plants was carried out using multiple means such as cytology, morphology, protein marker, and DNA-based molecularmarkers. Therefore, DNAmarkers have been reported as an important tool to evaluate the genetic homogeneity and true-to-type nature of micropropagated plants (Cheruvathur et al., 2013). Among them, RAPD is a convenient method for analyzing genetic fidelity (Williams et al., 1990). The previous reports have mentioned that RAPD-based detection of genetic polymorphism has been successful in describing somaclonal variability or homogeneity of micropropagated individuals of numerous plant species (Cheruvathur et al., 2013; Haque and Ghosh, 2013; Kumar et al., 2013). The objective of this study was to investigate the influence of different types and concentrations of cytokinins alone or in combination with auxins on in vitro regeneration of Aglaonema ‘Valentine’. RAPD marker was employed to confirm genetic fidelity of the regenerated plantlets. Materials and Methods Plant material and surface sterilization. Stock plants of Aglaonema ‘Valentine’ were grown in a shade greenhouse with an average noon photosynthetic photonflux density (PPFD) of 180 mmol·m·s and mean daily temperature of 25 C in the nursery of El Kenana Company, Tanta, Egypt. Aglaonema shoots (5–10 cm long) were defoliated and washed under running tap water. Then, they were rinsed thrice with distilled water and sectioned to 4to 5-cm segments containing three to four nodes. They were disinfected for 3 min in 70% ethanol followed by 10 min in a solution of 0.1% (w/v) mercuric chloride containing two to three drops of Tween-20 (Loba Chemical Company, India). After three rinses with sterile distilled water, explants were cultured for 8weeks onMSmedium (Murashige and Skoog, 1962), containing 3% (w/v) sucrose and 2.0 g·L gelrite for induction of axillary shoots. Shoot multiplication. Aglaonema axillary shoots (2.5–3.0 cm in length) were cultured in a cylindrical culture jar (375-mL capacity) containing 60 mL MS basal medium supplemented with 30 g·L sucrose and solidified with 2.0 g·L gelrite. Different concentrations of BA (0, 1, 3, 5, and 7 mg·L), Kin (0, 1, 3, 5, and 7 mg·L), TDZ (0, 0.5, 1.0, 1.5, and 2.0 mg·L), NAA (0, 0.5, and 1.0 mg·L), and IBA (0, 0.5, and 1.0 mg·L) were added to the media before autoclaving, depending on the objective of the experiment. MS basal medium without PGRs served as control. Received for publication 5 Nov. 2015. Accepted for publication 30 Jan. 2016. This project was supported by the King Saud University, the Deanship of Scientific Research, the College of Food and Agriculture Sciences, and the Agriculture Research Center. Corresponding author. E-mail: threemelmahrouk@ yahoo.com. 398 HORTSCIENCE VOL. 51(4) APRIL 2016 Shoot elongation and in vitro rooting. Shoot clusters of Aglaonema were cultured on MSmediumwithout PGRs for their subsequent growth and elongation. The cultures were kept at 25 C and 35mmol·m·s PPFD (16 h/d) for 4 weeks. Shoots (>3 cm long) were separated and used for rooting in different strengths of MS basal medium (full and half strength) supplemented with different concentrations of IBA or NAA at 0, 1, 3, and 5 mg·L. Culture conditions. The cultures were incubated at 25 ± 2 C under a 16-h photoperiod provided by cool-white fluorescent tubes at 35 mmol·m·s PPFD. Acclimatization. Plantlets at the three to five leaf stage were transplanted into culture pots (5 cm diameter) filled with a mixture of sterilized peatmoss and perlite (1:1). The plantlets were covered with a clear plastic film during the first 10 d of culture in the growth chamber and watered with a nutrient solution containing half MS salt strength. The environment in the growth chamber was adjusted to 25 ± 2 C air temperature, 60% to 70% relative humidity, and 100 mmol·m·s PPFD with a 16-h photoperiod using halide lamps. Plant DNA extraction and RAPDpolymerase chain reaction conditions. DNA was extracted from fresh leaves (oldest two leaves on the plant) of the mother plant and seven acclimatized plants (two or three plants every treatment) resulted from the best treatments of in vitro shoot multiplication (3 mg·L BA + 1 mg·L NAA, 1.5 mg·L TDZ + 0.5 mg·L NAA, and 1.5 mg·L TDZ + 1 mg·L NAA) by cetyltrimethylammonium bromide according to Doyle and Doyle (1990). Polymerase chain reaction (PCR) was performed and repeated three times using six random decamer primers (Table 1) (Al-Saghir and Abdel-Salam, 2015; Joshi et al., 2009). RAPD-PCR was carried out in presence of 1· Taq DNA polymerase buffer (10 mM Tris-HCl of pH 8.3, 50 mM KCl, 1.5 mM MgCl2), 100 mM dNTPs, 5 pmol single random primers, 25 ng DNA template, and 0.5 unit of Taq DNA polymerase in a total volume of 25 mL. PCR amplification was performed in an automated thermal cycler (MJ Mini; Bio-Rad, Foster City, CA) programmed as follows, 95 C for 4 min followed by 40 cycles of 1 min for denaturation at 94 C, 30 s for annealing at 35 C and 2 min for polymerization at 72 C, followed by a final extension step at 72 C for 7 min. The amplification products were resolved by electrophoresis in 1.5% agarose gels in 0.5· Tris-borate-EDTA (TBE) buffer and documented on Gel Documentation system (UVITEC CAMBRIDGE Company, Cambridge, UK). This work was conducted at ElKenana Lab. of plant tissue culture, Tanta, Egypt during the years 2013 and 2014. Experimental Design and Statistical Analysis Experiments were set up in a completely randomized design and each treatment had three replicates. Each replicate was represented by a culture jar containing four shoots rendering a group of 12 shoots per treatment. Observations on shoot multiplication as well as in vitro rooting were recorded after 8 weeks of culture. Data were subjected to analysis of variance using SAS program (Version 6.12; SAS Institute Inc., Cary, NC). The mean separations were carried out using least significant difference tests and significance was determined at P # 0.05, 0.01, and 0.001. Results and Discussion Effect of cytokinins on in vitro shoot multiplication and growth. Shoot multiplication of Aglaonema was significantly influenced by type and concentration of cytokinins (Table 2). The highest shoot number (2.5 and 2.3 shoot per Table 1. List of the used primers and their nucleotide sequences. Primer name Sequence (5#!3#) OPK-11 AATGCCCCAG OPB-03 CATTG OPA-10 GTGATCGCAG OPA-04 AATCGGGCTG OPA-05 AGGGGTCTTG O

Micropropagation and Genetic Fidelity of the Regenerants of Aglaonema ‘Valentine’ Using Randomly Amplified Polymorphic DNA