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−1), kinetin (Kin; 0, 1, 3, 5, and 7 mg·L−1), thidiazuron (TDZ; 0, 0.5, 1.0, 1.5, and 2.0 mg·L−1), naphthalene acetic acid (NAA; 0, 0.5, and 1.0 mg·L−1), and indole-3-butyric acid (IBA; 0, 0.5, and 1.0 mg·L−1) 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−1 TDZ and 1 mg·L−1 NAA. In vitro rooting was easily achieved with 100% at all concentrations of NAA and IBA supplemented to half- or full-strength MS medium. 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.
Mohammed Elsayed El-Mahrouk, Yaser Hassan Dewir, and Yougasphree Naidoo
El-Sayed Mohamed El-Mahrouk, Eman Abdel-Hakim Eisa, Mahmoud Abdelnaby Hegazi, Mohamed El-Sayed Abdel-Gayed, Yaser Hassan Dewir, Mohammed Elsayed El-Mahrouk, and Yougasphree Naidoo
Phytoremediation is an environmentally friendly and effective method of reducing contaminating ions to very low levels. In this study, the effects of different concentrations of cadmium (Cd), copper (Cu), and lead (Pb) on vegetative growth and the chemical and biochemical compositions of Salix mucronata as well as the potential for phytoextraction of these metals by plant organs were investigated. S. mucronata had the highest survival percentage (100%) in the presence of CdCl2, CuCl2, and Pb acetate up to 80, 200, and 850 mg·kg−1 in soil, respectively. A negative influence of these metals on vegetative and chemical parameters was observed relative to the control plants. The potential role of antioxidant enzymes in protecting plants from oxidative injury was examined by analyzing the antioxidant enzyme activities of plants grown in contaminated and control soils. Enzymatic activities and electrolyte leakage were higher in the plants grown in soil with increasing heavy metals than in the control plants. The bioconcentrating efficiency of Cd, Cu, and Pb in plant organs was estimated to be medium [bioconcentration factor (BCF) of 1–0.1]; an exception was the BCF of Cu in the roots, which was estimated to be intensive (BCF < 1). Concentrations of 60 mg·kg−1 CdCl2, 50 mg·kg−1 CuCl2, and 650 mg·kg−1 Pb acetate caused significantly higher translocation compared with other levels of each pollutant. The biomass tolerance index was less than 1. Additionally, S. mucronata accumulated Cd, Cu, and Pb in the following order: roots > stems > leaves. Therefore, the risk of contamination through leaf fall can be minimized. Therefore, S. mucronata could be a good candidate for phytoremediation of Cd-, Cu-, and Pb-contaminated soil.
Mohammed El-Sayed El-Mahrouk, Yaser Hassan Dewir, and Salah El-Hendawy
Grape (Vitis vinifera) waste management is a major problem in juice production, but it could be transformed into a major opportunity if the waste was recycled and used as a nursery growing medium. The aim of this study was to evaluate the suitability of four composts based on squeezed grape fruit waste (SGFW), mixed with coir or vermiculite in a one-to-one ratio by volume to form 13 growing media, for seed germination and seedling growth of ‘Mrs. Burns’ lemon basil (Ocimum basilicum var. citriodora). The final germination percentage (FGP), corrected germination rate index (CGRI), survival percentage, and seedling growth of ‘Mrs. Burns’ lemon basil were the variables measured. Pure SGFW reduced seed germination and seedling growth. The medium combining pure SGFW with vermiculite in a one-to-one ratio by volume was optimal for seed germination and seedling growth; in this medium the highest FGP, CGRI, survival rate, and growth parameters were recorded. The negative effects of pure SGFW composts were eliminated by mixing all composts with coir or vermiculite. These waste recycling media are low-cost products that can be beneficially used in nurseries on a commercial scale.
Antar Nasr El-Banna, Mohammed Elsayed El-Mahrouk, Mohammed Eraky El-Denary, Yaser Hassan Dewir, and Yougasphree Naidoo
For the first time, genetic diversity among 14 ornamental palm accessions originating from different countries and grown in different regions in Egypt were examined. Identification of genetic variation and phylogenetic relationships in ornamental palms would be useful for its genetic identification, improvement, and conservation. Genetic polymorphism was analyzed using the randomly amplified polymorphic DNA (RAPD) as well as protein markers. The electrophoretic pattern of protein analysis produced 21 bands distributed in all accessions with molecular sizes ranging from 11.8 to 99.3 KDa. Some accessions possessed some bands, which were absent in other accessions and could be used for their identification. Furthermore, 10 RAPD selected primers were employed to determine genetic variation among the 14 palm genotypes as well as to test the effectiveness of RAPD primers as a genetic marker. RAPD analysis revealed a high level of polymorphism (100%) among the studied accessions. A total number of 310 amplified bands were generated across the studied genotypes with an average of 30 bands per primer. Cluster analysis using sequence alignment was done to generate a dendrogram verifying the relationship among the 14 studied ornamental palms, with an average similarity matrix range of 0.00 to 0.08 and 0.39 to 0.93 for RAPD and protein markers, respectively. It is concluded that, both SDS-protein and RAPD markers are equally important for genetic analysis and are suitable for the characterization of ornamental palm collection.
Mohammed Elsayed El-Mahrouk, Mossad K. Maamoun, Antar Nasr EL-Banna, Soliman A. Omran, Yaser Hassan Dewir, and Salah El-Hendawy
In vitro ovule culture could be used to generate homozygous lines through the production of haploid plants. The present study reports on in vitro regeneration and production of haploid plants through ovule cultures and identification of the regenerated haploids using flow cytometry. The ovules were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations of 6-benzyladenine (BA), kinetin (Kin), 2,4-dichlorophenoxyacetic acid (2,4-D), and naphthalene acetic acid (NAA) at 0, 0.5, 1, and 2 mg·L−1 for their gynogenesis. Among different plant growth regulators (PGRs) tested, 2,4-D at 2 mg·L−1 produced direct gynogenesis. The highest callogenesis percentage (100%) was obtained on MS medium containing 1 mg·L−1 2,4-D and 2 mg·L−1 NAA. Flow cytometry analysis was used to identify the regenerated haploids. It also confirmed gynogenic occurrence at 1 and 2 mg·L−1 2,4-D with percentages of 21.7% and 41%, respectively. Therefore, 2,4-D proved effective for the induction of haploids in black cumin. The regenerated haploids were developed on MS medium without PGRs. The obtained results of in vitro gynogenesis and haploid plant production can tremendously facilitate breeding programs of black cumin.