Journal of Ornamental Plants
Volume:12 Issue: 2, Spring 2022

An in vitro propagation method of English yew (Taxus baccata L.) through organogenesis method using kinetin (Kin) and indole 3-butyric acid (IBA) as plant growth regulators and apical bud as explant is presented. Apical buds excised from mother plants were inoculated on Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of Kin (0.00, 0.50, 1.00 and 2.00 mg l–1) as a cytokinin and IBA (0.00, 0.50, 1.00 and 2.00 mg l–1) as an auxin. Results showed that the highest number of node (6.75) was obtained on MS medium containing 2.00 mg l–1 Kin. The maximum shoot number (5.00) was obtained on MS medium supplemented with 1.00 mg l–1 Kin together with 1.00 mg l–1 IBA. The largest number of root (6.50) was produced on explants grown on medium enriched with 2.00 mg l–1 Kin together with 1.00 mg l–1 IBA. Plantlets were transferred to pots filled with perlite and peat moss in equal proportions for acclimatization. These plantlets were acclimated and successfully established in cultivation beds. .

Marigold is widely used as an ornamental-medicinal plant. Interaction between nanoparticles (NPs) and biological systems is one of the most promising areas of research in modern nanoscience and technology. Researchers have reported the uptake of cerium oxide or ceria (CeO2) NPs by plants. The aim of this investigate was to determine the impacts of nanoceria on seed germination, growth and biochemical characteristics of 9-day-old seedling of marigold (Calendula officinalis L.). Seeds were germinated in Petri dishes containing eight various dosages of nanoceria (0, 0.05, 0.1, 0.2, 0.4, 0.8, 1.6, and 3.2 g/L). After 9 days, early growth and biochemical parameters were measured. Results showed that seed germination, fresh and dry weights of seedling, and lengths of radicle, plumule, and seedling stimulated at 0.05 and/or 0.1 g/L of nanoceria but retarded at higher dosages (after 0.2 or 0.4 g/L) of NPs. The contents of H2O2, malondialdehyde (MDA) and lipoxygenase (LOX) activity incremented after 0.2 g/L of nanoceria. The activities of antioxidant enzymes and protein content were incremented at higher dosages of nanoceria. Also, the activity of phenylalanine ammonialyase (PAL), phenol content, and antioxidant capacity stimulated at 0.8 to 3.2 g/L of nanoceria. The proline content improved at 0.2-3.2 g/L of nanoceria. Altogether, the results confirmed the inducive oxidative stress of nanoceria that was accompanied by plant defense system include antioxidant enzymes, phenolic compounds and compatible osmolytes such as proline. These results showed that nanoceria at the low dosages (0.05 and/or 0.1 g/L) caused a positive induction on marigold germination and seedling growth but by increasing in its dosage (more than 0.2 g/L), the results was reversed and showed toxicity that forced the plant to activate its defense systems.

The molecular basis of the plant meristem's dormancy-release is a sophisticated process and poorly understood. To find genes related to the release of the dormancy of the P. abies apical meristem, an expressed sequence tag analysis was used. The preliminary data for two cDNA libraries was gathered using the Harvard University database (Dormancy and dormancy-release libraries with 6987 and 6981 EST, respectively). The EGassembler software was used to assemble all EST sequences in order to find similarity between two libraries. After that, all contigs were processed using CLC bio software's X-blast against a non-redundant protein database. To detect genes with differential expression in two libraries, the IDEG6 software and the Audic-Claverie test were utilized. The GoMapMan comparative classification tool was used to categorize functional catalogs. All unigenes were grouped into 35 functional catalogs, of which 10 significantly different functional catalogs were identified, including major CHO metabolism, hormone metabolism, stress, transport, secondary metabolism, cofactors and vitamins, nucleotide metabolism, redox-regulation, mitochondrial electron transport/ATP synthesis, and fermentation. So far, there has been no report on the role of secondary metabolites in regulating plant meristem dormancy. This study provides insight into the probable function of secondary metabolites as major regulators of the apical meristem's dormancy in P. abies. In addition, redox and epigenetic changes downstream of hormones also appear to be involved in dormancy regulation. The potential of ROS specificity in terms of the spatio-temporal properties that characterize the expression of antioxidant enzymes allows them to be used as biomarkers in major developmental stages to develop a set of features in woody species that promote growth, wood, and fiber attributes. This research also provides information about the molecular mechanisms of the morphogenesis process in Norway spruce.

Petunia (Petunia hybrida) is one of the important plants in horticultural industry. This plant is being used as a model ornamental plant and is one of the most important plants in floriculture market. Flavonoids are the main pigment in this plant. So, genetic engineering with the goal of color alteration in petunia is focused on flavonoids. To gain a global perspective on genes differentially expressed in petunia’s flowers pigment pathway, we investigated the expression of chalcone isomerase (chi) as an essential gene in biosynthesis pathway of pigment production in different types of flower color of petunia and various stages of flowering in this plant. Also, we measured the concentration of total flavonoids, anthocyanins and naringenin to evaluate the probably relationship between the expression profile of chi gene and the concentration of mentioned pigments. The results indicated that chalcone isomerase expression had different profile in different petal color of P. hybrida. So that, the most chi expression observed in red petunia flowers. Naringenin concentrations was the most value in this color flower. In comparison of flowering stages, stage 1, had the most expression. In other words, when the flowers fully closed (bud stage), chi expression and concentration was in the highest value. Our results showed that chi is a key gene in pigment biosynthesis pathway so that in absence of this gene, pigment pathway will be stopped. Identification of effective genes in different pathways of secondary metabolite production will assist in accurate selection of genes for genetically modification of pathways and production of various metabolites.

Supplying safe, natural, and inexpensive food sources for the growing population of the world is a need of contemporary societies. Edible flowers are a new natural source in humans’ food basket. In this regard, the nutritional value of five edible flowers including Tagetes erecta L., gladiolus, yucca (Yucca gloriosa), chrysanthemum, and Hibiscus syriacus were explored. According to the results, the African marigold flowers had the highest total flavonoids (16.13 mg CE g-1 FW), total phenols (14.48 mg GAE g-1 FW), antioxidant capacity (87.89 % DPPH inhibition), vitamin C (30.60 mg 100 g-1 FW), and proteins (1.56 %). The highest carotenoids (482.57 μg g-1 FW), Fe (2.54 mg 100 g-1 FW), and Zn (0.27 mg 100 g-1 FW) were recorded by the yucca flowers. The chrysanthemum flowers exhibited the highest Ca (47.25 mg 100 g-1 FW) and Mg (2.60 mg 100 g-1 FW), and the H. syriacus flowers exhibited the highest anthocyanins (30.86 mg/100 g-1 FW). In addition, the gladiolus flowers showed the lowest total flavonoids (11.17 mg CE g-1 FW), anthocyanins (2.14 mg 100 g-1 FW), proteins (0.52 %), Fe (0.36 mg 100 g-1 FW), Ca (9.11 mg/100 g-1 FW), and Zn (0.14 mg 100 g-1 FW). The chrysanthemums had the lowest total phenols (0.54 mg GAE g-1 FW) and vitamin C (8.16 mg 100 g-1 FW), the yuccas had the lowest antioxidant capacity (47.76% DPPH inhibition), and the H. syriacus flowers had the lowest carotenoids (362.17 μg g-1 FW). So, given the phenol and antioxidant compounds, minerals, and proteins of the studied flowers, they can be included in the food basket of households as natural food sources.

In order to evaluation of mitigation effect on salinity stress on the morphological and biochemical properties of ornamental marigold plant (Tagetes erecta L. Nana), an experimental was carried out in factorial arrangement base on randomized complete block design in three replications at Khorasan Razavi Agriculture Research and Education Center in 2018. The first factor was four salinities (0, 4, 8, 12 dS m-1) and the second factor was potassium silicate (PS) at three levels (0, 100 and 150 ppm). The results showed that the highest plant height was obtained at zero salinity with application 100 ppm PS. The highest shoot dry weight was recorded at salinity of 8 dS m-1 with 150 ppm PS. The highest amount of leaf potassium was observed at salinity of 12 dS m-1 with using of 100 ppm PS and the highest amount of root potassium was obtained at 4 dS m-1 salinity treatment with 100 ppm PS. The results was also showed that in marigold plant at high salinity (more than 8 dS m-1), potassium silicate composition could not have a favorable effect on plant growth. The use of PS in salinity of 12 dS m-1 was able to reduce the concentration of sodium in leaf tissues and increase the amount of potassium, although the amount of potassium increase was higher in low salinities. In general, the use of potassium silicate can be considered as a supplement in plant nutrition at low salinities.