Journal of Ornamental Plants
Volume:7 Issue: 2, Spring 2017

In the floriculture industry, the need for heat tolerant bedding plant cultivars is increasing because of the rising temperature around the world. A pot experiment was carried out to examine the impacts of four heat stress durations (0, 7, 14 and 21 days) on growth and ornamental traits to determine the relative heat tolerance of four cultivars of calendula (Calendula officinalis). Growth and development were quantified by measuring plant height, total leaf area, shoot and root fresh weight, shoot and root dry weight, time to flowering, flower number, average flower size, and flower longevity. Plant height, leaf area, and shoot and root growth at 35-42°C were significantly lower than those at normal temperatures (20-30°C). Time to flowering increased with temperature. Flower number, size and longevity were reduced by heat stress, so that among all durations, plants exposed to heat stress for 21d had the least mean. Longer heat stress reduced the plant height, leaf area, shoot and root growth, SPAD value, flower diameter and flower longevity of all cultivars., However, the range percentage reduction in growth and flowering parameters were different among cultivars. Experiment to determine the membrane damage showed an increase in percent electrolyte leakage with exposure of plants to higher temperatures. The studied cultivars differed in their sensitivity to heat stress. The results indicated that better cell membrane stability, higher shoot and root growth, and later flowering led to greater heat tolerance in ‘Indian Prince’ compared to other cultivars.

Effects of exogenously applied methyl jasmonate (MeJA) and sucrose on vase life and non-structural carbohydrate concentration in petals and leaves of cut ‘First Red’ roses were investigated. Roses were placed in sealed plastic containers and received MeJA vapour treatment (0.1 μL MeJA L-1) for 24 h at 20°C. Flowers were then placed in individual bottles containing 0 or 2% (v/v) sucrose solution. Flower petals and the two uppermost five-leaflet leaves were detached on days 0, d 5 and d 10 of vase life. Samples were individually snap-frozen in liquid nitrogen and freeze-dried. Non-structural carbohydrates were extracted and quantified using standard HPLC coupled to evaporative light scattering detection. The MeJA vapour treatment enhanced vase life of flower and foliage of ‘First Red’ roses. Significant differences were observed between foliage life of cut ‘First Red’ roses that were treated with MeJA and sucrose, but not for flower life. Rose stems treated with MeJA in the absence of sucrose had an extended vase life compared to roses treated with 2% sucrose alone (14.0 vs. 12.8 days of vase life). Sucrose and myo-inositol, and to a lesser extent glucose concentrations in petals of cut roses decreased during vase life, even when flowers were supplied with 2% sucrose. Concomitant to this, fructose levels in petals increased during vase life. Neither sucrose nor MeJA had a significant effect on any of the sugars measured in petals of cut roses. In contrast, significant differences were apparent for all sugars measured in leaves that were treated with MeJA and sucrose solutions. The combination of MeJA and 2% sucrose solution sharply increased endogenous sucrose concentration in leaves, but the opposite was shown in the absence of 2% sucrose. Sucrose treatment alone did not consistently alter endogenous sucrose concentration. Interactions between MeJA and sucrose on sugar metabolism are discussed.

Alstromeria has beautiful flowers that is popular in the world. One of the most problem in commercial of this flower is ethylene sensitivity and bacterial contamination in stem end of cut flowers. In this experiment, effect of essential oils of bitter orange (0, 25 and 50 mg l-1) and lawson cypress (0, 100 and 200 mg l-1) and nonchemical treatment (with and without) with 18 treatments, 3 replications and 54 plots were tested on vase life and quality of cut Alsteromeria. ANOVA showed that interaction effect of mentioned treatments were significant on all of traits except loss of fresh weight. Results showed that L200B50S0 (200 mg l-1 essential oil lawson cypress × 50 mg l-1 bitter orange without splitting) and L200B0S1 (200 mg l-1 essential oil lawson cypress × 0 mg l-1 bitter orange with splitting) had highest vase life. Also, lowest bacterial population found in L200B50S1 (200 mg l-1 essential oil lawson cypress × 50 mg l-1 bitter orange with splitting).

Magnetic field improved germination parameters. The germination of Catharanthus roseus seeds is lost under salinity conditions. The effect of different strengths of magnetic field and exposure durations on the germination of C. roseus seeds under salinity conditions (19 mS cm-1) were investigated. The experiment was conducted with factorial arrangement based on a completely randomized design (CRD) with 3 magnetic field strengths (50, 100 and 150 mT) and 3 exposure durations (10, 20, and 30 minutes). It was found that exposure to magnetic field improved seed germination under salinity conditions, so that the highest germination percentages of (74.44 and 73.05%) were obtained from 20 and 30 minutes exposure to the 100 mT magnetic field, respectively, which resulted in 28% higher germination than control. Also, these treatments were found to be the best for germination rate and vigor indices I and II. The highest radicle length (2.37 cm) and plumule length (3.50 cm) were related to the 20 minutes exposure in 50 mT magnetic field and the 10 minutes exposure in the 100 mT magnetic field. The highest radicle dry weight of 0.24 g and plumule dry weight of 0.81 g was observed in treatment of 10 minute exposure to the100 mT magnetic field.

This experiment was carried out to evaluate the effect of silver nanoparticles pulsing treatment (0, 25, 75 and 125 mg L−1) on vase life and some postharvest physiological parameters of cut rose flower ʻHigh & Magicʼ in sucrose solution (0, 2 and 3%). This research performed as a factorial experiment based on a completely randomized design with three replications under 23 ± 2 °C, 60 ± 5% RH and 12 µmol m−2 s−1 light intensity (cool white florescent tubes) under a daily light period of 12 h. Results showed that 125 mg L−1 silver nanoparticles without sucrose or with 2% sucrose had the lowest stem end bacteria. Pulse treatments with silver nanoparticles at all concentrations improved solution uptake, maintenance of the relative fresh weight, flower diameter and chlorophyll fluorescence ratio (Fv/Fm) as compared to control. The highest amount of flower opening with the largest flower diameter was observed in 75 mg L−1 pulsed silver nanoparticles with 2% sucrose solution on day 9 of vase period. Control flowers (deionized water) without or with 2% sucrose exhibited the shortest vase life. The concentrations of 75 and 125 mg L−1 with 2% sucrose or without it had the longest vase life as compared to other treatments.

The concentrations of cadmium, copper, nickel, zinc and lead were investigated in various components of smooth-leaved elm (Ulmus carpinifolia) tree in three sites (polluted, moderately polluted, and control) in Abadeh, Iran, in July 2015. The experiment was conducted using factorial experiment in a Completely Randomized Design with three replications. The concentration of heavy metals was measured in the mentioned indicator using atomic absorption spectroscopy method. The results showed that polluted and control sites had the highest and lowest Cd, Cu, Ni and Zn, respectively, indicating that vehicular traffic was the main source of these heavy metals. The moderate level of Pb concentration (0.15 mg l-1) was observed in control site. The accumulation pattern of the studied elements was in the order of Ni=Zn>Cu>Cd>Pb. The concentrations of heavy metals were lower than the permitted limits except Cd in leaf, root and stem. Smooth-leaved elm (U. carpinifolia) tree can be used as a biomonitor of heavy metals pollution in Abadeh city.

This experiment was conducted to investigate the effect of paclobutrazol as an anti-gibberellin on some morpho-physiological characteristics of Petunia × grandiflora ‘Bravo Blue’, and determine the optimum concentration of paclobutrazol for drought resistance in this plant. The experiment was carried out as factorial based on completely randomized design with three replications in greenhouse. The studied factors were included paclobutrazol in four levels (0, 25, 50 and 75 mg a.i. l-1) and drought stress in three levels (irrigation when soil moisture reached 90 %, 75 % and 50 % of field capacity). Results showed that the application of paclobutrazol had increased the number of flowers, aerial part dry weight and number of lateral branches, and the application of this substance decreased the plant height, root dry weight and amount of carotenoids. While, paclobutrazol did not have significant effect on the electrolyte leakage, main branch number and leaf area of petunia. Also, the results showed that drought stress increased the number of flowers per plant, and reduced the content of chlorophyll, carotenoids, flower diameter, shoot and root dry weight and leaf area of petunia. Application of 75 mg a.i.­ l-1 paclobutrazol had the greatest effect on height controlling of petunia plant under drought stress. Carotenoids and chlorophyll content was increased by increasing the paclobutrazol concentration under 50% of field capacity. Generally, the results indicated that the application of paclobutrazol under severe drought stress could prevent chlorophyll and carotenoids decline, and had partially been effective in overcoming adverse effects of drought stress.

important cut flowers in tropical and sub tropical areas of the world and has the seventh rate of production between all cut flowers of Iran. In order to investigate different effects of storage temperatures (8 weeks at 4 °C, 4 weeks at 4 °C 4 weeks at 20 °C, 8 weeks at 12 °C, 4 weeks at 12 °C 4 weeks at 20 °C and 8 week at 20 °C) and different concentrations of gibberellic acid (0, 150 and 300 ppm) on quantitative characteristics of tuberose ‘Double’, a factorial experiment was carried out in a Randomized Complete Block Design with three replications. The effects of treatments were investigated on fresh and dry weight, height and number of flower stems, length of spike, speed of germination and flowering, weight and diameter of florets, number and weight of bulbs, and flower longevity. Qualitative and quantitative investigation of growth and flowering indices showed that the highest number of stems was recorded at 20 oC storage temperature, which was 20% higher than that at 4 oC storage temperature. Stem weight showed a significant correlation with most growth parameters. The most important effect of studied treatments was observed on growth speed. Speed of bulbs germination was affected only by storage temperatures (P