International Journal of Horticultural Science and Technology
Volume:1 Issue: 2, Autumn 2014

The susceptibility to Terbacil of six randomly selected strawberry cultivars (‘Aromas’, ‘Chambly’, ‘Harmonie’, ‘Kent’, ‘La Clé des Champs’ and ‘Seascape’) was analysed using chlorophyll florescence (CF) in comparison with visual observation, in an attempt to develop a method for use in a breeding programme to select herbicide-resistant strawberry lines. Terbacil was applied at one of five rates (0, 0.55, 1.10, 2.20 and 3.30kg/ha), and CF was measured 1, 3, 7 and 14d after application. Visible damage was assessed using a scale of 0 to 10 (where 0 is no damage and 10 is the death of the leaf). All cultivars showed a decrease in CF after herbicide application, but this decrease was not the same for all cultivars. ‘Chambly’ and ‘Harmonie’ had the lowest CF changes, and both appeared to be tolerant or resistant to Terbacil, in keeping with previously reported results. In contrast, ‘Kent’ and ‘Aromas’ showed a significant decrease in CF on the third day after treatment with Terbacil at 2.20 and 3.30 kg/ha, an indication that their chlorophyll system had been damaged by herbicide application without any visible signs of leaf damage. It is concluded that CF can be used as an alternative and more accurate method to evaluate seedlings in a strawberry breeding programme aimed at selecting herbicide-resistant lines. This method could be very useful, especially for those lines that do not show any visible leaf damage from herbicide application, even though their chlorophyll system is damaged enough to cease plant growth and development.

One of the most effective ways to propagate Lilium is by using tissue culture techniques, preferably through bulblet production. In addition to the surviving percentage of Lilium bulbs after transplantation, the small size of in vitro bulblets compared to commercial bulbs and bulblets‟ dormancy are the most important constraints to commercializing Lilium micropropagation. Different concentrations of sucrose or sorbitol as carbohydrate sources were investigated as maturation and enlargement factors on in vitro bulblets of Lilium longiflorum cv. „Ceb-dazzle‟. Five concentrations of gibberellic acid and 4°C cold treatment for 6, 7, 8, 9, 10 and 11 weeks in the greenhouse were studied in relation to the dormancy breaking of three in vitro Lilium bulblets cultivars: „Simplon‟, „Navona‟ and „Ceb-dazzle‟, which belong to the Oriental, Asiatic and LA hybrids. The results showed that 3% of sucrose and two weeks of culture significantly increased the bulblet maturation and enlargement of „Ceb-dazzle‟. One mg L-1 gibberellic acid for six weeks, or cold treatment for six to eight weeks, had significant positive effects on the dormancy breaking of in vitro bulblets of Lilium cultivars.

Plantlets grown in conventional tissue culture systems usually encounter physiological and anatomical abnormalities including inability to photosynthesize, low chlorophyll content, open stomata, lack of a cuticle layer in the leaf, abnormal xylem parenchyma etc. Photoautotrophic and photomixotrophic systems could diminish these problems. The purpose of this study was to increase the chlorophyll content and photosynthetic ability of shoots grown in vitro and to improve the adaptation of walnut plantlets. Walnut apical leaf buds were cultured in vessels containing DKW medium supplemented with 0, 15, 30 and 45 g L-1of sucrose. The vessels were closed with a clear polypropylene lid with two syringe filters on the lid (V1) or with a 50 mm microporous polypropylene membrane (V2). Natural ventilation had a significant effect on most of the growth indices. Furthermore, different levels of sucrose had significant effects on growth characteristics. Natural ventilation increased chlorophyll content significantly. By using ventilated vessels containing 15 g L-1 sucrose, the total chlorophyll was significantly increased. Stomata under non-ventilated conditions were spherical with wide openings, whereas those in ventilated vessels were elliptical with narrow openings. As a result, ventilated vessels with 15 g L-1of sucrose produced healthy plantlets.

A major portion of the Iranian fig (Ficus carica) industry is located in high-salinity regions, and salinity is an important limiting factor in the production of this fruit. The present study was conducted to investigate the changes of leaf antioxidant-enzyme activity, proline and total protein content in two fig cultivars with two leaf shapes: ‘Anjir Sabz’ with lobate and palmate leaves, and ‘Shah Anjir’ with lobate and palmate leaves, under salt stress condition. The seedlings were exposed to different NaCl concentrations so that six different electrical conductivity levels of 0.6, 3, 6, 9, 12 and 15 dSm-1 were achieved in pots. This experiment was performed as factorial based 6×2(2) in a completely randomized design with four replications and two seedlings in each replicate. The results showed that as the soil salinity increased, the proline and protein contents of both cultivars were increased. However, palmate leaves of both cultivars accumulated more proline and protein than those of their lobate leaves. The activities of antioxidant enzymes increased in seedlings of both cultivars; however, superoxide desmutase and catalase showed more activity in palmate leaves than lobate leaves. There were no significant differences between the two leaf shapes in relation to peroxidase. The results seem to suggest that seedlings with palmate leaves are more salt tolerant than seedlings with lobate leaves.

An important part of plant in vitro techniques is the sterilization of explants and the maintenance of aseptic conditions. Ideally, sterilizing materials should be effective on a vast range of microorganisms at low density. Nowadays, the use of compounds such as essential oils (EOs) and nanoparticles is applicable in microbiology studies. The main objective of this experiment was to study the substitution probability of silver nanoparticles (SNPs), thymol and carvacrol as novel sterilization agents in the tissue culture of Cynodon dactylon. Explants were sterilized with 70% ethanol for 2 min, and then 30% Clorox for 15 min. Sterilization complementary treatments (SNPs, thymol and carvacrol) were applied at different concentrations (100 and 200 mg l-1) with exposure times of 30, 60 and 120 min. According to the results, infection of bermudagrass explants was controlled successfully by SNPs, thymol and carvacrol. Examination of various concentrations in different exposure times showed that 200 mg L-1 SNPs in combination with 100 mg L-1 thymol in 60 min inhibited microbial growth. Thymol and carvacrol were more effective than SNPs in controlling bacteria and fungi contaminations. Finally, these novel agents could be used as an alternative to common chemical treatments for elimination and control of microbial population explants in in vitro conditions.

The drastic decline of precipitation over the past decade along with overuse of chemical inputs and consequent soil fertility reduction are the most important problems in the approach to agricultural expansion, particularly in urban landscaping. Therefore, an experiment was designed to examine the effects of different irrigation levels (40, 70 and 100 % of field capacity, or FC) and different vermicompost (VC) levels (0, 2.5 and 5 %) on the morphophysiological parameters of Zinnia elegance ‘Dreamland Red’ in a factorial experiment based on completely randomized design with three replications. Results indicated a significant reduction in root/shoot ratio, flower diameter, flower longevity, water use efficiency (WUE), photosynthetic pigments and nutrient uptake, along with reduction in the FC, while VC application improved these features. Based on the results, the highest electrolyte leakage and free radicals were observed in the 40 % of FC level without VC treatment, while the highest antiradical property and phenolic compounds were obtained at the same FC level along with 2.5% VC. Moreover, the highest WUE was observed at 2.5% VC with 70% FC, compared to 40% FC with no VC application. The flower diameter and longevity, as the most important indicators of the zinnias’ quality, were significantly affected by the interaction effects of irrigation and organic fertilizers.

Grapes are significant sources of nutritional antioxidants as well as biologically active dietary components. This study was carried out to determine the amount of total phenols, anthocyanins and antioxidant activity of 35 grapevine (Vitis vinifera L.) cultivars grown in Fars province (Iran). Ripened bunches were randomly harvested from grapevine collection in Zarghan (Fars province, Iran) Agricultural Research Center, and then were transferred to the laboratory. Berry size (length, diameter, and weight), skin weight, acidity, vitamin C, total soluble solids (TSS), pH, phenols, anthocyanins and antioxidant activity were evaluated. The results showed that total phenols, anthocyanin and antioxidant activity in the berries varied among the investigated cultivars. ‘Gandome Uromia’ (Red, 64) and ‘Rishbaba Uromia’ (Red, 75) cultivars had the highest values of antioxidant activity and total phenols. The lowest amount of phenol was obtained from ‘Divaneh Kashmar’ (White, 135) cultivar. Anthocyanin and antioxidant activity were the lowest in ‘Jeshnion Bavanat’ (White, 105) cultivar. Antioxidant activity had a positive significant correlation with amount of phenols and anthocyanin. In general, it was found that different cultivars in this study had a vast range of antioxidant activity from 14.55 to 66.47%.

This study was conducted to evaluate the effects of exogenous polyamines, isopropyl ester, 2, 4-D and naphthalene acetamide application on yield and quality of date palm of ‘Kabkab’ cultivar. The inflorescences sprayed with 2, 4-D isopropylester (0, 10, and 20 mg L-1), naphthalene acetamide (0, 80, and 120 mg L-1), putrescence and spermidine (0, 0.1, and 1.0 mM), three or six weeks after pollination. The highest rate of initial fruit drop (42.2%) was obtained when fruits were treated with naphthalene acetamide at a concentration of 120 mg L-1, which was significantly higher than the control (32.0%). Fruit treated with polyamines had a higher yield than the control. The lowest total soluble solids (TSS) (21.5%) were found in spermidine 0.1 mM and the highest TSS (46%) was found in the control. Polyamines decreased fruit total soluble solids content (TSS) compared with untreated fruits, and also delayed fruit maturity for at least 17 days. In conclusion, polyamine application significantly affected yield, physical and chemical characteristics of date cultivar under the study and it may be recommended to be applied in cultural practices to enhance production and improve the fruit quality of date trees orchards.

The purpose of this study was to evaluate the effects of Nano-silver (NS), calcium chloride (CaCl2) and their combinations on Gerbera jamesonii ‘Carambole’ cut flowers. The experiment was conducted as a completely randomized design (CRD) with 10 treatments and four replications, with three flowers in each replication. Treatments consisted of 5 mg L-1 NS, 1% and 2% CaCl2, 5 mg L-1 NS+ 1% CaCl2, 5 mg L-1 NS + 2% CaCl2, 0.1% and 0.2% CaCl2, 5 mg L-1 NS + 0.1% CaCl2, 5 mg L-1 NS + 0.2% CaCl2 and a control. It was revealed that CaCl2 postharvest spray, NS in a vase solution, as well as their combinations could significantly increase the vase life of gerbera flowers. The longest postharvest life of treated flowers was obtained from 5 mg L-1 NS and 5 mg L-1 NS + 1% CaCl2 treatments. The highest solution uptake was observed in 5 mg L-1 NS, 5 mg L-1 NS + 2% CaCl2 and 5 mg L-1 NS +1% CaCl2 treatments. Furthermore, application of NS and CaCl2 resulted in a reduced loss of relative fresh weight. The application of CaCl2 alone was able to increase all mentioned traits; however, this increase was less than 5 mg L-1 NS, 5 mg L-1 NS + 1% CaCl2 and 5 mg L-1 NS + 2% CaCl2 treatments. Additionally, in vitro cultivation and microscopic counting of microorganisms showed that microorganism growth at the end of flowering stems had been largely restricted by using NS solely or in combination with CaCl2.

Freezing injury is an important limiting factor in the production of pomegranate in Iran.The aim of the present study was to evaluate the effect of paclobutrazol (PBZ) on cold hardiness of pomegranate (Punica granatum L.) cv. ‘Malas Saveh’. Different concentrations of PBZ including 0 (control), 31, 62, 125 or 250 mg L–1 were sprayed on one-year-old plants in August and the electrolyte leakage of their stems was measured at three acclimation stages (November, January, and March). PBZ treatments, especially at 125 and 250 mg L–1 concentrations increased cold hardiness, and corresponding soluble carbohydrates and proline contents. The highest variation in freezing tolerance was observed between control and PBZ-treated plants in January, and the lowest found in November. Irrespective of PBZ treatment, correlations between cold hardiness and soluble carbohydrate concentrations were stronger, compared to proline. Soluble carbohydrates were higher in January, associated with deep dormancy, whereas the maximum proline content was detected in March, at deacclimation stage. Results suggest that PBZ application can reduce low temperature-induced dysfunction of cell membrane through increasing soluble carbohydrates and proline contents.