JOURNAL OF ORNAMENTAL PLANTS (JOURNAL OF ORNAMENTAL AND HORTICULTURAL PLANTS)
Year:2018 | Volume:8 | Issue:2 |Papers Count:6

Abiotic stress conditions can be imposed on plants through either poor water quality or adverse climate condition. These types of stress affect plant growth and development throughout their life cycle. Plants that are tolerant to drought are therefore valuable, and turf grasses have the potential to grow tolerant. Turf grasses provide ground cover and offer multiple benefits, from their aesthetic value which affects our daily lives to their preservation of land against erosion. The objectives of the present work were to find the ideal media for callus induction and regeneration followed by overexpressing theP5CS1 gene encoding proline for improving drought stress resistance inFestuca arundinacea Schreb. The husks of tall fescue seeds were removed and the seeds were then sliced longitudinally. The result of this treatment showed a greater callus induction efficiency in comparison with intact seeds in the culture media. In addition, an increase in regeneration efficiency was observed in media supplemented with 2, 4-D along with BAP. The average of G418‒resistant calli obtained in the experiment was around 10%. The heterologous transformation ofP5CS1 in F. arundinacea background was confirmed by PCR and the transient Gus assay. More than 90% of calli expressed the uida gene which can most probably convey resistance to drought stress.

Carnation ( Dianthus caryophyllusL.) is valuable in terms of production and exports in the world. Increased vase life of cut flowers is an important factor for their market acceptability. For this purpose this study was carried out to examine the effect of plant essential oils as compared to 8-hydroxy-quinoline sulfate on the control of bacteria population and the longevity of carnation cut flowers on the basis of a complete randomized design with 14 treatments, control (distilled water), control+alcohol (2%), 8-HQS at three levels (100, 200 and 400 mg l-1), and the essential oils of dill seeds, caraway seeds and aromatic geranium, each one at three levels (50, 100 and 150 mg l-1) continuously with 3 replications, 42 plots – each plot including 5 flowers. The recorded traits included vase life, vase solution bacteria population, fresh weight loss, increasing the soluble solids, ionic leakage, ethylene production, chlorophyll a and b. The results of this study showed that the longest vase life was obtained from the treatment of alcohol 2% with 15.83 days. Also, among the treatments containing essential oil, dill (100 mg l-1), geranium (50 mg l-1), caraway (100 mg l-1) and 8- hydroxyquinoline sulfate (400 mg l-1) as better treatments are considered.

Soil and water salinity substantially constrain crop and biomass production.To investigate the changes in morphological parameters of lisianthus (Eustoma grandiflorum) cultivars under CaCl2 salinity conditions a greenhouse experiment was conducted. Cultivars namely, ‘Champagne’ (C1), ‘Lime Green’ (C2), ‘Blue Picotee’ (C3) and ‘Pure White’ (C4), were subjected to salt stress (0–30 mM CaCl2) in a washed sand culture and the morphological responses were measured. The results showed that salinity affected all of the considered parameters, so that, as salinity levels increased, plant height, shoot fresh and dry weight and leaf area in all cultivars decreased, while, root length, root fresh and dry weight and root: shoot length ratio increased.However, the changes in ‘Pure White’ and ‘Lime Green’ were less than in‘Champagne’ and ‘Blue Picotee’. The regression analysis of the relationship between CaCl2 salinity levels and seedlings height or root: shoot length ratio defined two groups with different slope coefficients: C1 and C3 as salt sensitive cultivars and C2 and C4 as salt tolerant cultivars. The results showed that salinity threshold of C1 and C3 was 25 and 30 mM CaCl2 respectively, while C2 and C4 in 30 mM CaCl2 showed no significant differences with control. The results suggests that C2 and C4 could be recommended as resistant cultivars due to attain higher growth, water balance, shoot fresh and dry weight and leaf area in response to CaCl2 salinity compared with C1 and C3.

Zinnia is an annual plant with the long flowering period from late spring to mid-autumn. It is a popular plant for landscape. In the present study, the effect of two types of growth promoting bacteria andAzolla compost on some ornamental characteristics of Zinnia were evaluated in pot cultivation and greenhouse conditions. The factorial experiment was conducted in three replications based on a completely randomized design with two factors, includingAzolla compost in 6 levels (0, 10, 20, 30, 40, 50 percent) and growth promoting bacteria in 3 levels (without bacteria, Azospirillum and Azotobacter bacteria). The results showed that growth promoting bacteria (Azospirillum and Azotobacter) and Azolla compost had a significant effect on the investigated factors. Treatment of 50%Azolla compost and Azospirillum compared to other treatments had higher leaf and root fresh weight, leaf nitrogen and plant height. Moreover, 10%Azolla compost and Azospirillum was the best treatment in terms of leaf and root dry matter content. According to conducted evaluation, Azospirillum with less percentage of compost had a significant effect on dry weight and Azospirillum with a higher percentage of compost had a significant effect on fresh weight. Besides, a higher percentage of compost inAzospirillum in treatment Azospirillum and 50% compost had a significant effect on leaf nitrogen and height of the stem.

In recent years, excessive use of chemical fertilizers and lack of organic fertilizers have caused to reduce the rate of soil organic matter in Iran. The increased use of chemical fertilizers in agriculture causes environmental problems such as soil physical degradation and soil nutrient imbalances. This study was conducted to investigate the effects of foliar and soil application of humic acid on some morphological and physiological characteristics of Rosa chinensis ‘Baby Masquerade’ in a completely randomized design with two factors including four concentrations of humic acid (0, 500, 1, 000 and 2000 mg/L) and two application methods (soil and foliar application) for 8 times (every 15 days) with three replications and two observations per replication under controlled greenhouse conditions.The results showed that humic acid had additive effects on anthocyanin and total soluble solids content. It should be noted that the increase in the content of total soluble solids resulted in the increase in anthocyanin. Foliar application of 500 mg/L humic acid significantly increased chlorophyll content and photosynthetic rate. Also, foliar application of 1000 mg/L humic acid improved total soluble solid content more than the other treatments. Humic acid had significant effects on leaf area index and shoot and root fresh and dry weight. Overall, it seems that humic acid can improve morphological and physiological characteristics of Rosa chinensis var.‘Minima’.