مجله گل و گیاهان زینتی
سال چهارم شماره 2 (پاییز و زمستان 1398)

Cut roses are one of the most important flowers in the ornamental plant industry that are widely cultivated all over the world. Longevity and postharvest quality is the most important characteristic in evaluating the quality of cut flowers which is influenced by various pre and post-harvest factors. Light, as one of the environmental cues in the postharvest condition of cut flowers, can play an important role in its qualitative characteristics. To the best of our knowledge, no detailed study has been reported so far in this case. This study aimed to investigate the intensity of light required for preserving the quality of cut flowers during the postharvest handling. This experiment was carried out as factorial in a completely randomized design with three replications in a postharvest room. The area was divided into three sections by optical shutters and the light intensity levels were applied in each section. Treatments were designed at three levels of light intensity of 15, 25 and 50 µmol m-2 s-1 emitting by LED lighting bulbs. The studied traits were vase life, activity of catalase and peroxidase enzymes, proline, relative fresh weight, anthocyanin, carotenoid and chlorophyll content. Results showed that the highest activity of catalase and peroxidase enzymes were at light intensity of 15 and 50 µmol m-2 s-1, respectively, and their activity decreased significantly during the vase life. The proline content increased with time and the highest level was observed in all three treatments on day 9 after harvest. The highest relative fresh weight was observed at light intensity of 15 µmol m-2 s-1 and in the vase life on the third day after harvest. The lowest relative fresh weight was also in the light intensity of 25 µmol m-2 s-1. In spite of these observations, however, there was no significant difference between the vase life, carotenoids, chlorophyll and anthocyanins of cut flowers at light intensities of 15, 25, and 50 µmol m-2 s-1. According to the results of this study, in order to improve the qualitative and quantitative characteristics of cut flowers during the post-harvest period, the light intensity of 15 µmol m-2 s-1 is recommended for flower shops industry.

The crisis of oak decline in recent years has destroyed big sections of the Zagros forests, and altering the structure of the forest masses. Finding ways to restore deforested forests and increase the ability to deploy new seedlings in the field can help reforest. In this study, the potential of titanium dioxide nanoparticles was used to modify the damaging effects of drought stress on oak seed. Drought stress is one of the most important factors in limiting the seed germination of plants. Treatments consisted of 4 levels of titanium nanoparticles (0, 10, 50 and 100 mg L-1) and 4 levels of drought stress (0, -3, -6 and -9 bar) applied by polyethylene glycol 6000. Zero levels in both treatments were considered as the control treatment. The experiment was conducted as a factorial experiment in a completely randomized design with two factors and three replications. Analysis of variance showed that drought stress had a negative effect on most growth factors, especially at high levels. Drought stress above -6 bar, had a negative effect on root growth and treatment of 50 mg L-1  titanium dioxide with -2 bar of drought stress caused the highest root fresh weight (7228.3 mg) and maximum root length of 127.33 mm. High drought stress levels decreased leaf number and leaf area. Although there were no significant differences between the treatments of nanoparticles on stem length and number of leaves, treatment with 50 mg L-1 nanoparticles had higher numerical value than others. The results showed that the highest germination percentage and seedling emergence were obtained at the concentration of 50 mg L-1 of TiO2 and drought stress in 0 and -3 bar, and the lowest germination percentage was observed at no-treatment and drought stress in -9 bar. The interactions between nanoparticles and drought stress at the 1% level were significant for the crown diameter changes. The concentration of 50 mg L-1 nanoparticles at the drought stress in -6 bar, increased the crown diameter by about 2.63 mm on average. The highest number of lateral roots was obtained at a concentration of 50 mg L-1  and a -3 bar of drought stress. The results showed that when the nanoparticles were treated with drought stress, the plant increased its stress tolerance threshold for better survival under stress conditions. Based on the findings of this study, it can be concluded that a concentration of 50 mg L-1 nanoparticles is the most suitable treatment for improving root characteristics and moderating drought stress effect on oak. The present study is the first study of nanoparticle treatment on vegetative characteristics of oak seed.

Nowadays, in vitro techniques are proposed for commercial and rapid propagation of Phalaenopsis species. The present study aims were investigating the quality of seed germination of 5 cultivars of Phalaenopsis orchid, and correlation of their traits in the culture medium. The study was conducted using the green and ripe seeds in terms of 5 cultivars of orchid as Dubrovnik, Memphis, Andorra, Bucharest and Nottingham in a factorial experiment based on a completely randomized design. The capsules were formed using self-pollination of flowers in each cultivar. The green seeds were harvested at the stage of completely formed capsules and the ripe ones were harvested at the stage of initial browning of the capsule shell. The seeds were cultured on Chenchr('39')s culture medium. The number of germinated and non-germinated seeds were counted 18-33 days after their culture. The following factors were measured for each treatment: germination percentage, germination rate, germination index, mean daily germination, mean germination time and coefficient of germination rate. Correlation coefficient of %98 between the measured characteristics indicated a significant correlation between germination rate and germination index. The results of cluster analysis that was conducted based on all the measured germination characteristics showed the maximum mean distance between clusters; ultimately, that separated into two groups at Euclidean distance of 1.25 which Dubrovnik and Memphis cultivars were classified in the first group and Andorra, Bucharest and Notingham cultivars were classified in the second group. The key characteristics in separating cluster among the groups were considered to be germination percentage, germination rate, germination index and mean germination time. Discrimination function analysis test confirmed the grouping among the cultivars in a 100% manner. Both Hoteling-Lawley Trace as well as Roychr('39')s Greatest Root tests showed the highest value of 5.23 to confirm the grouping. It is concluded that using cluster analysis and correlation coefficient Notingham had the highest value in germination factors based on the germination percentage, germination rate and germination index which were regarded as key traits for the breeding programs.

Chrysanthemum morifolium (Ramat.) Hemsl. belongs to the Asteraceae family. It has a relatively long vase life but the flowers wilt after two weeks or more of harvesting. This study aimed to investigate the effect of supplementation of various levels of orange peels extract on chrysanthemum vase life. concentrations of 0, 5, 15 and 25 ppm of orange peels extract was used in the vase solutions. The study was performed as a factorial experiment based on a completely randomized design with three replications and the treatments were long-term and short-term (24 hr pulses). The studied characters included vase life, number of stem ends bacteria, total protein content, catalase and peroxidase activity, soluble weight, flower weight, petal water content and chlorophyll content. Orange peels extract increased the vase life of chrysanthemum, the longest vase life (16.33 days) was belonged to long-term treatment using 25 ppm orange peel extract. The lowest population of stem ends bacteria with the 228.84 Log10 CFU ml-1 was belonged to the treatment of 25 ppm orange peels extract which with decreasing the concentration of the extract, the population of bacteria at the stem ends increased significantly. The activity of catalase and peroxidase enzymes was significantly increased by treatment of 25 ppm orange peels extract compared with control treatment as 3.04 and 1.41 mg protein-1min-1, respectively. Overall, the concentration of 25 ppm orange peels extract is considered as an effective concentration for increasing chrysanthemum vase life and quality.

The need to use native plants in urban green spaces has increasingly felt. Due to the global economic problems, native plants, in addition to compliance and stability, can play an important role in currency saving and probably to save the needless expenditure of the more import ornamental plants. The purpose of this study was to introduce native domesticated plants for green space of Tehran. This study was carried out on domesticated plants in the southern Alborz habitat of the National Botanical Garden of Iran. The plants were transferred from the field to the habitat, adapted and settled over the years. The introduced species are among the most successful species in establishment. Twenty-three species were introduced based on their ornamental potential for planting in Tehran.

Papaver macrostomum Boiss. and A. Huet is a herbaceous ornamental plant that grows as a wild flower in different areas of Iran. It produces different medicinal compounds. Experiment was conducted to study the effect of ethyl methane sulfonate and gamma ray on physiological and phytochemical characteristics of papaver. The experiment was carried out as a factorial experiment based on completely randomized design with three replications in greenhouse conditions from 2017-2018. Experimental treatments included ethyl methane sulfonate at four levels (0, 0.1, 0.2 and 0.3%) and Gamma ray at four levels (0, 10, 50 and 100 Gy). Characteristics of chlorophyll, carotenoid, flavonoid, phenol, and sugar content as well as antioxidant activity were measured. The results showed that treatments had a significant effect on the studied factors. Mutation treatments increased the characteristics and the highest amount of chlorophyll, carotenoids, antioxidant activity, and sugar were belonged to the treatment of 0.1% ethyl methane sulfonate and the highest amount of phenol and flavonoid was observed in the treatment of 0.3% ethyl methane sulfonate. Overall, the results showed that the use of mutagenic agents can affect the physiological and phytochemical traits of P. macrostomum. However, the mutagenic agent of ethyl methane sulfonate alone was more effective than the other treatments.