IRANIAN JOURNAL OF HORTICULTURAL SCIENCE AND TECHNOLOGY
Year:2010 | Volume:11 | Issue:3|Papers Count:7

Hormonal requirements for micropropagation of a local Karaj cultivar of hazelnut were studied. Shoot tips were surface-sterilized with 10% commercial bleach (5% sodium hypochlorite) for 10 min. Two experiments were conducted. In the first one, the effects of different concentrations of GA3 (0, 0.1, 0.5, 1.0, 3.0 and 5.0 mg l-1) were investigated. In the second experiment, explants were cultured on NRM medium with four cytokinins including BA (0, 2.5, 5 mg l-1), Kin (0, 1.5, 3.5 mg l-1), 2ip (0, 2.5, 7.5 mg l-1), TDZ (0, 0.01, .025 mg l-1) and their combinations. The mean length and number of shoots were significant on media containing 0.5 mg l-1 GA3. The highest proliferation rate was observed with 5 mg l-1 BA, however, in this concentration the shoot length decreased. The longest shoots and leaf number were obtained on medium supplemented with 2.5 mg l-1 2ip. These shoots were much more vigorous and it was possible to propagate them by single node. For rooting number significant differences were found between NRM and half-strength media. The plantlets were successfully acclimatized in jiffy-7.

Freezing stress is one of the most important problems for pomegranate growers in Iran. For example most pomegranate orchards were completely destroyed in the Khorasan province and other places because of severe winter freeze in 2008. Therefore, a factorial experiment based on completely randomized design (CRD) was performed during winter 2009. Six genotypes included (‘Shirin e Poost Ghermez’, ‘Poost Sefid’, ‘Shahvar’, ‘Torsh e Malas’, ‘Shalghami’ and ‘Shishe Cap’) and 8 temperatures in the range of -10 to -24oC as well as a control were compared. Results showed that the amount of browning, proline content, electrolyte leakage and antioxidant activity were increased by freezing incubation in all cultivars, whereas survival percentage was decreased. Not any re-growth was recorded in 3 cultivars (‘Shirin e Poost Ghermez’, ‘Poost Sefid’ and ‘Shahvar’) at -18oC but ‘Torsh e Malas’, ‘Shalghami’ and ‘Shishe Cap’ showed 30, 21.5 and 61.2 respectively survival percentages. The cultivar ‘Shishe Cap’ could stabilize its membrane structure and electrolyte leakage up to -20oC. The proline content of ‘Shishe Cap’ showed a 12-fold increase at -24oC in comparison with control. Therefore, it seems that ‘Shishe Cap’ pomegranate was able to retain its survival effectively compared with the other studied cultivars.

Warm-season annual flowers are transplanted to the bed and hence their weeds may be controlled by preemergence herbicides. The purpose of this experiment was to evaluate the effects of two preemergence (treflan and dacthal) and one postemergence grass control (gallant) herbicides on weed control of transplanted marigold, Petunia and Ageratum flowers in Isfahan. Treatments were complete hand weeding, control, treflan (2 l h-1), dacthal (8 kg h-1) and gallant (5 l h-1). Evaluation took place three times during the experiment and weed dry matter and height, density and plant longevity were determined in each time. Hand weeding was the most effective followed by treflan, dactal, gallant and control, respectively. Lowest dry weight of the weed was recorded with hand weeding and treflan, while the highest dry weight was obtained with the control, respectively. Highest plant height and density were observed with hand weeding, followed by treflan, dacthal, gallant and control, the longest plant longevity with treflan and Petunia. The overall results revealed that treflan was the most effective herbicide followed by dacthal and gallant. The results showed that treflan as a preemergence herbicide maybe used to control weed of the marigold, Petunia and Ageratum bed without any apparent plant injury.

Micropropagtaion of ornamental plants using tissue culture technique, is a new efficient method for propagation of plants. Lilium is an ornamental plant, which is highly valuable in international flower markets. Due to Iran’s dependency to the importation of Lilium bulbs, it is highly desirable to propagate this plant efficiently in the country. One of the most effective techniques for propagation of Lilium is in vitro direct bulblet production using scale explants. To find the best plant growth regulators concentrations for direct bulblet production of Lilium longiflorum cv. ‘Gironde’, four concentrations of BAP (0, 0.03, 0.3, 3 mg l-1) in combination with three concentrations of NAA (0, 0.03, 0.3 mg l-1) were evaluated. Scale explants placed on MS basal medium supplemented with 60 g l-1 sucrose and 7 g l-1 agar after surface sterilization. The substrate for acclimatization and growth of in vitro bulblets were also studied. The experiment conducted in factorial based on completely randomized design (CRD) and statistical analysis was made using SAS software and mean comparison was carried out using Duncan's multiple range test. Bulblet production parameters including number of scales per bulblet, bulblet length, weight and diameter, rooting percentage, and position of bulblet formation in each explant (basal, lateral and distal) were analyzed. The results showed that BAP and NAA had a significant effect on all measured parameters. The combination of 0.03 mg l-1 BAP with 0.3 mg l-1 NAA produced the most bulblet number and the highest rooting percentage. Basal part of the explants, produced the most bulblets in comparison with lateral and distal parts. Peat was the best substrate (soil mixture) for in vitro bulblet's growth and development for Lilium longiflorum cv. ‘Gironde’.

The respiration of cut flowers during postharvest period has an effect on reduction of quality and vase life. In this study effect of increased levels of CO2 and decreased O2 concentrations using modified atmosphere packaging (MAP) was applied to reduce the cut rose flower respiration rate in order to delay the aging process. This research was conducted in a factorial experiment using a completely randomized design (CRD) with 2 factors and 3 replications. Treatments included the following three gas combinations: without gas injection (G2), 5% O2+3% CO2+92% N2 (G3), 5% O2+ 95% N2 (G4) and G1 as control along with four sampling times: 4 (T1), 7 (T2), 11 (T3) and 14 (T4) days. After treatment, flower placed in storage at 4±2oC and 60% Rh. According to the results, the highest vase life was 12.4 days in G2 treatment after 4 days maintaining in cold room and the lowest flower diameter was observed in flowers inside packages in G2, G3 and G4 treatments compared to controls. Regarding weight of flowers in packages, there was no reduction observed. In G2, G3 and G4 treatments amount of O2 decreased and CO2 increased. Highest amount of soluble solids in stem observed in G4 treatment packages after 14 days and the lowest amount of ethylene observed in packages without gas injection after 11 days of maintaining.

To study the relationship between four wild and domestic species of almond, the karyosistematic and morphologic assessments on the A. communis L., A. corduchoruom Bornm, A. trichamygdalus Woronow and A. lycioides var. horrida Spach were performed by the karyological methods. After collecting and recording the seeds morphological features, the meristem cells of the root tip was used for cytological assessments. In each specimen, ten suitable metaphase plates were chosen and photographed until the morphology of the chromosomes was completely obvious. The standard karyotype was prepared for the species separately and the parameters of the chromosomes including the complete length of the chromosomes, the length of the long arm, the relative of the length long arm to short arms (AR) etc. were calculated. There was significant difference between all of the species that can be employed to recognize the species. All of the studied species were diploid and the numbers of the chromosomes was 2n=16. The base number of the chromosomes in all of the species was X=8. Average size of chromosomes in species of this genus was 2.42 micrometer. A.communis L. had the most similarity with the species of A. lycioides Var. horrida Spach. A. trichamygdalus Woronow and A. corduchoruom Bornm. also had the most similarity with each other. Finally, the studied species were classified in two groups cytologically. These results were consistent with mean comparison test based on Duncan’s method. The two groups were different in cytologically traits terms.

To evalute the effect of sowing date and plant density on quantitive and qualitative characteristics of ‘Purple Top White Globe’ turnip, an experiment was conducted at farm of Agricultural Faculty of Islamic Azad University of Abhar in growing season of 2007. Experiment was conducted in a split plot experiment based on a randomized complete block design with four replications. Three leveles of sowing dates (Aug.10, Aug.19 and Aug.28) were in main plots and three plant densities (53, 38 and 29 plant m-2) that obtained with 7.5, 10.5 and 13.5 cm in row and about 25 cm in row space were in subplots. Different traits such as total yield, root yield, leaf yield, percentage of dry matter, dry matter yield, leaf length, brix, were recorded. Results showed that sowing date had significant effects on total yield, leaf yield, dry matter and leaf length. First and second sowing dates produced the highest and third sowing date produced the lowest total yield, leaf yield and leaf length. Plant density had significant effects on total yield, leaf yield, root yield and dry matter. Increasing plant density resulted in increasing yield. The highest yield was obtained in plant densities of 53 plant m-2 and 38plant m-2. Plant density had not any significant effects on other traits. There were no significant effects between sowing date and plant density.