JOURNAL OF ORNAMENTAL PLANTS (JOURNAL OF ORNAMENTAL AND HORTICULTURAL PLANTS)
Year:2015 | Volume:5 | Issue:2|Papers Count:8

Salicylic acid (SA) is considered to be plant signal molecule that plays a key role in plant growth, development, and defense responses. The physiological mechanism of exogenous SA to affect the senescence of cut lisianthus flowers during vase life was investigated. Fresh cut lisianthus flowers were treated with distilled water (control), 0.5, 1 and 2 mM SA and then held at 25oC up to 12 days. Exogenous SA supply at 1 mM extended vase life, which was associated with reduced electrolyte leakage and MDA content. SA treatment also reduced activity of lipoxygenase (LOX), which is responsible for membrane lipid peroxidation. SA treatment also enhanced activities of catalase (CAT) and ascorbate peroxidase (APX) and decreased H2O2 accumulation during vase life. Thus, exogenous SA supply could maintain membrane integrity by increasing antioxidant system activity, thereby retarding the senescence of cut lisianthus flower during vase life.

In vitro propagation of plant has played a very important role in rapid multiplication of cultivars with desirable traits and production of healthy and disease-free plants. In the present investigation, the objectives were to optimize the micropropagation of Rose hybrid ‘Black Baccarat’ cultivar. In proliferation step, the nodal segments (1.5 cm) was cultured on both liquid and solid media (MS, VS and WPM). The results showed that the highest shoot proliferation was obtained on VS medium. The highest amount of multiplication and the growth rate were obtained in the liquid medium. For rooting, three concentrations of VS mineral salts (full-, half-, and quarter-strength) containing NAA (0.5 mM) were tested in semi-solid and liquid media. Root initiation influenced by mineral concentration in the medium. The investigation showed that the highest number of roots was observed in semi-solid 1/4 VS medium. Variation in multiplication and growth rate of explants can be explained on the basis of water potential and mineral availability to the explants in the liquid medium.

The germination power of orchids (Orchidaceae family) seems to be too weak due lack of albumen. The study carried out with various treatments including pollination time and GA3 for breaking dormancy and increasing seed germination of orchids. The effect of pollination time (8 periods from January to August) and gibberellic acid (0, 500, 1000 and 1500 mg L-1) were studied on germination of Phalaenopsis orchids. Capsules containing seeds with 2, 4, 8 and 10% hypochlorite sodium were disinfected. In order to grow seedlings the culture medium of cocopeat and coal with the ratio of 1:5, and cocopeat, coal, industrial shell, and polystyrene with the ratio of 1:1:2:4 was used. Results indicated that the most appropriate concentration of sodium hypochlorite in order to disinfect the capsules was 2%. The bestmonth for pollination of flowers was January. The highest yield from one capsule obtained 15.3 seedlings in the medium of 1/2 MS containing 1000 mg L-1 gibberellic acid. The produced seedlings were transferred to greenhouse in order to hardening. The highest rate of viability was obtained through the medium of cocopeat, coal, industrial shell, and polystyrene particles.

In order to study on effect of magnetic field on germination characteristics and early growth of marigold (Calendula officinalis L.) seeds an experiment was carried out in laboratory conditions in Arak University of Iran. Seeds were magnetically exposed to magnetic field strengths, 100 or 200 mT for different periods of time; D1 (control), D2 (1 h), D3 (6 h), D4 (12h), D5 (24 h) and D6 (continuous). Mean germination time (MGT) and the time required to obtain 10, 25, 50, 75 and 90% of seeds to germinate were calculated. The germination time for each treatment were in general, higher than control values, in the other word in treated seeds time required for mean seed germination time increased nearly 4 hours in compared non treated control seeds. T10 for doses D3, D4 and D5 significantly higher than the control values. Mean germination time significantly increased when the time of seed exposed at magnetic field treatments increased, about 3 and 2 hour, respectively. According to experiment results of seedling dry weight (SLDW), seed resource depletion percentage (SRDP) and shoot length (STL) showed more decrease with increasing of the exposure time in the magnetic field.

The aim of this study is investigation on effect of stem end splitting and Geranium essential oil on vase life on quality of cut chrysanthemum (Dendranthema grandiflorum L.). This experiment arranged as factorial based on RCD with 2 factors of stem end splitting at 2 levels (with splitting and without splitting) and Geranium essential oil at 6 levels (0, 1, 2, 4, 8 and 10 %), with 12 treatments, 3 replications, 36 plots and 144 cut flowers. In this experiment traits such as vase life, water absorption, fresh weight, dry matter percent and °brix were measured. ANOVA showed that different among treatments was significant for vase life, °brix and fresh weight in 1% probability and for dry matter percent and water absorption in 5% probability. Results showed that different treatments improved vase life compared to control and maximum vase life was achieved in 5 cm splitting + 10% Geranium essential oil with 18.41 days compared to control (7.05 days).

This study was carried out to investigate the effect of different preservative solutions to improve the keeping quality of tuberose (Polianthes tuberosa cv. Single). These preservative solutions (treatments) were: T1= 2% sucrose + 200 mg/l AgNO3, T2= 2% sucrose + 200 mg/l AgNO3 + 25 mg/l citric acid, T3= 2% sucrose + 300 mg/l HQS, T4 = 2% sucrose + 300 mg/l HQS+ 25 mg/l citric acid, T5= 2% sucrose + 200 mg/l AgNO3 + 300 mg/l HQS, T6= 2% sucrose + 200 mg/l AgNO3 + 300 mg/l HQS+ 25 mg/l citric acid, T7= 0.01 % sodium hypochloride, T8= 0.05 % sodium hypochloride, T9= 0.10 % sodium hypochloride and T10= tap water (control). The results showed that all treatments had improved the keeping quality and vase life of the cut flowers comparing to control ones. Among all these treatments, 2% sucrose + 200 mg/l AgNO3 + 300 mg/l HQS+ 25 mg/l citric acid showed best water uptake, water loss uptake ratio, percentage of maximum increase in fresh weight of the cut flower stem and vase life which was extended up to 10 days. According to the results of this research it is concluded that, 2% sucrose + 200 mg/l AgNO3 + 300 mg/l HQS+ 25 mg/l citric acid are suitable for prolongation of tuberose vase life.

Ophiopogon japonicus is a perennial, ornamental foliage plant, which belongs to the family Liliaceae. It has a high demand in the local and international export market due to the presence of glossy white-green stripped lanceolate leaves. Improved leaves and plants of O. japonicus will be more popular in the floriculture industry. Hence, objective was to investigate the growth responses of O. japonicus for best potting media and fertilizer treatments. Shoots of O. japonicus trimmed up to 4 cm from the root-shoot junction were potted in two potting media as soil type 1, coir dust, compost and sand as 1:1:1 and soil type 2, sand, coir dust 1:1 by volume. High nitrogen fertilizer, balanced fertilizer and high phosphorous fertilizer were applied as foliar sprays in three concentrations (×1/2, ×1 and ×2 times of the RBG recommended dosages) and distilled water was used as the control. There was a significant (p<0.05) effect of growing media on the O. japonicus leaf length, plant fresh weight, shoot dry weight, root dry weight, number of leaves and number of shoots. However, there was no significant difference between the control and fertilizer treatments on leaf length, shoot dry weight, number of leaves and number of shoots while there was a significant difference among fertilizer treatments on plant fresh weight and root dry weight. Most effective potting media and fertilizer treatment for O. japonicus were sand: coir dust media (1:1) and Royal Botanic Gardens, Sri Lanka-recommended dosage (RBG) of fertilizer treatments (high nitrogen (2.5 g/L), balanced (1.25 g/L) and high phosphorous fertilizer (2.5 g/L), respectively.

To study the effect of different concentrations of potassium in the nutrient solution and water stress on the quality and quantity yield of Lilium LA cv.Termoli, a pot experiment was conducted based on completely randomized design in sand and perlite medium (50:50) in three levels of potassium (Kfree, 6 mM K and and 12 mM K in Hoagland solution) with three replications. In the present study, the growth indices, post-harvest life of flower and potassium and chlorophyll contents were measured in shoots. The results showed that the plant dry/fresh weight and vegetative height was highest in 6 mM potassium treatments. Lily postharvest life at 6 mM K was increased 5.7 days relative to k-free conditions. The chlorophyll a, b and total content in nutrient solution without K were lower than in nutrient solution with 6 and 12 mM potassium.