مجله علوم و فنون باغبانی ایران
سال چهاردهم شماره 2 (تابستان 1392)

Increasing levels of heavy metal compounds produced as the mining and industrial activities of human are the important source of environmental pollution. In urban areas, ornamental plants can be considered as a tool to remove these pollutants. However, the responses of this group of plants to high concentrations of these pollutants should be determined. This study was performed as a factorial experiment in a CRD. The treatments consisting of cadmium at four levels (0, 20, 40 or 80 mg kg-1 soil) and four doses of Cu (, 20, 40 or 80 mg kg-1 soil). One month after treating the soils inside the pots, hollyhock seedlings were transplanted. Plants were grown for a period of four months and then sampled for content of Cd, Cu, proline content, ion leakage, photosynthetic pigments and some growth parameters determination. The highest concentration of cadmium belonged to 20 and 4 mg kg-1 in the case of roots and to 80 mg kg-1 in the case of shoot parts. The highest values of Cu accumulation in both roots and shoot parts were obtained with application of the highest level of Cu. Increasing Cd and Cu levels, significantly increased proline content and ion leakage but decreased photosynthetic pigments. Generally, it can be suggested that hollyhock plant can be used as a phytoremediator to remove mild levels of Cd and Cu pollutions.

Molecular markers increase the speed and accuracy of breeding programs. The new preliminary breeding program of rootstocks is undergoing in Iran. Present research was performed to optimize conditions for breeding program and evaluation of relationship between selected rootstock candidate genotypes and some drought tolerant rootstocks. Forty seven grapevine rootstock genotypes including 3 drought tolerant rootstocks and 44 candidate genotypes were sampled and evaluated with 11 microsatellite markers. Results showed there is 21% similarity between Iranian genotypes and Riparia, 1103P and 140Ru as grapevine rootstocks. Studied Iranian genotypes were divided in to 3 main groups. The third group with 39 genotypes included three unknown genotypes of the North East region of Iran, two early ripening genotypes ‘Yaquti’ and ‘Khalili’ with 55% similarity and some other Iranian cultivars. Likelihood based assignment approach was used to determine parents of unknown genotypes. Results showed specific hetero and homozygote loci for early ripening cultivars in 3 microsatellite markers included VVMD14, VVS2 and VMC4A1. Finally, two main center of variation includes Northeast (Khorasan) and South (Fars) of Iran, were separated. It appeared that allelic diversity of Khorasan is endogenous but allelic diversity of Fars is endo and exogenous. Results showed visible effect of habitat region on genetic structure of genotypes. It is concluded that the genotypes may be used directly as drought-tolerant rootstocks or as parents to planning control crosses.

In order to evaluate the yield and some morpho-physiological traits of Iranian Leek (Allium ampeloprasum Leek group) in response to salinity, two different Iranian leek landraces (Shadegani and Hamedani) were subjected to 0, 7, 14, 25 or 40 mM NaCl in soilless culture system. The layout was a factorial experiment in a completely randomized design. Salinity treatments were imposed by adding NaCl to half-strength Hoagland nutrient solution. By increasing the level of salinity stress, yield, number of leaves, leaf area and the percentage of dry matter were decreased and Hamedani landrace was more affected than the Shadegani. The ratio of root to leaf fresh weight was increased in response to salinity stress. By increasing the concentration of NaCl, leaf relative water content and the contents of a, b and total chlorophylls decreased while stomatal density were increased. The highest stomatal density were observed in highest level of salinity stress. Based on the present results, Iranian leek was evaluated as salt sensitive crop and Shadegani landrace was found more tolerant to salinity than the Hamedani.

In this study the effect of different concentrations of essential oils of cinnamon (Cinnamomum zeylanicum) and clove (Zyzygium aromaticum) (100 and 200 mg l-1 + 2% sucrose) and silver nanoparticles (SNP) (2, 4 and 6 mg l-1 + 2% sucrose) on the vase-life and some quantitative attributes of cut alstromeria cv. ‘Jamaica’ flowers were evaluated. This experiment was performed in completely randomized design with three replications in laboratory of postharvest physiology of faculty of agriculture, University of Tabriz. Results showed that SNP and cinnamon and clove oils treatments could delay the number of days to 50% petal fall compared to the non-treated control. All treatments also maintained relative fresh weight and solution uptake rate during the eight days of vase-life period compared to control treatments but the clove oil treatment has no positive effect on solution uptake rate. The 2 and 4 mg l-1 of SNP treatments could also maintain leaf chlorophyll index. There were no significant difference between two concentrations of cinnamon and clove oils of studied parameters and there were only significant difference between three concentrations of SNP of relative fresh weight and leaf chlorophyll index. SNP treatment had higher efficiency than the essential oils treatment of vase-life parameter. In overal, these results indicate that applying of 100 mg L-1 of essential oils and 2 mg L-1 of SNP can increase vase-life of alstromeria flowers.

This experiment was conducted to study the effects of humic acid and mycorrhiza fungi on fresh and dry weight, visual quality, root colonization, and some nutrient uptakes such as Fe, Zn, K and P of ‘Speedygreen’ perennial ryegrass, in the research greenhouse of Tehran University in spring and summer of 2009. After soil autoclaving, the inoculums of mycorrhiza fungi including of G. mosseae and G. intraradices were added to pots, then seeds were sown. Humic acid at different levels (0, 100, 400, and 1000 mg L-1) was sprayed on leaves and the measurements were conducted nine weeks after starting of treatments. The results showed that the medium and high concentrations of humic acid increased the height, fresh and dry weight, and visual quality in non-mycorrhizal plants (control). Control plants had better nutrient uptakes in 400 mg/L. Both fungi had positive effects on measured characters. G. mosseae was better in medium concentration on nutrient uptake, colonization and visual quality, while height, fresh and dry weight on control plant in during time were more. Both fungi had positive effect on uptake of Fe, while control had better P uptake. K and Zn uptake were positive after time. Humic acid had no effect on root colonization.

Water deficit damage productivity in agricultural and horticultural products in many regions of the world. In present study, the drought tolerance of 69 Russian grapevine genotypes were evaluated for drought tolerance in the collection of foreign grape genotypes in Grape Research Station. These genotypes were planted on 9 × 8 rectangular lattice design. Vitis vinifera var. White Bidaneh is regarded as control plots in three plots. In this experiment, related traits to the drought tolerance such as leaf relative water content, leaf cuticle diameter, leaf area, number of abaxial stomata, canopy temperatures and fruit ripening were measured. Data were analyzed by SPSS and MSTAT-C software and the means were compared using Duncan’s multiple range test (DMRT). Genetics parameters of characters such as heritability, phenotypic, genotypic and environmental variances and coefficients of variation were calculated by mathematical expectation of sum of mean square in ANOVA. For final morphological screen of genotypes to drought tolerance, ranking method on the base of compare means and cluster analysis were used. Results indicated that genotypes 14, 30, 35, 49, 54 and 60 were the best genotypes for morphological drought tolerance.

In this experiment, the effect of copper sulphate at various concentrations (0, 2, 4 and mM) as peroxidase inhibitors was studied on vase life, water uptake, relative fresh weight, anthocyanin, protein and malon dialdehyde content, peroxidase (POD) and superoxide dismutase (SOD) activity and postharvest quality of Eustoma grandiflorum cv. ‘Mariachi’ The results indicated that all treatments significantly (P < 0.01) increased vase life, water uptake and relative fresh weight. Among the treatments, 6 mM copper sulphate increased vase life up to 4 days, relative fresh weight to 16% and water uptake to 4.4 g stem-1day-1 in comparison to control. Similarly copper sulphate treatment increased anthocyanin content, SOD activity, but decreased malon dialdehyde content and POD activity with no effect on protein content. Copper sulphate at 6 mM concentration showed the most SOD activity (237.33 μmol g-1 FW-1) and the lowest POD activity (0.0067 μmol g-1 FW min) in comparison to control (respectively 198 for SOD and 0.03 μmol g-1 FW-1 for POD). Also 4 mM copper sulphate produced the most anthocyanin content (94.28 mg g-1 FW) and lowest Malon dialdehyde (23.94 nmol g-1 FW-1).

There are 10 to 12 species of genus Pyrus in the Alborz, Zagros mountain chains and north of Khorasan in Iran. Despite of high genetic diversity, there is no comprehensive information about physico-chemical traits of fruits of wild pear genotypes. In present study, some physical and biochemical traits including total soluble solids (TSS), percentage titratable acidity (%TA), TSS/TA, pH, vitamin C, antioxidant capacity, total phenolics content, total flavonoids content and the flavonoids compositions (catechin and chlorogenic acid) were measured. The results indicated that there was significant differences (P<0/01) except for antioxidant capacity. Fruit weight differed from 39.57 to 132.74 g, fruit lenght from 38.45 to 62.86 mm, fruit diameter from 41.45 to 64.26 mm, total soluble solids from 9.34 to 13.64 (°Brix), titratable acidity from 0.29% to 1.38%, TSS/TA from 7.21 to 35.40 and pH from 3.25 to 5.05. Genotype of 493 had the highest value of total phenolics content. According to the results of HPLC, chlorogenic acid and catechin in genotypes of 475 and 485 (106.8, 2.03 mg kg-1 FW, respectively) was higher than others. The results provided important information about the fruit quality and physico-chemical traits of fruits of wild pear genotypes investigated that may be used for breeding programs.

Grape micropropagation is generally carried out using MS or half strength MS medium along with BAP for proliferation and IBA for rooting. Present experiment was conducted to improve the efficiency of present culture media. Preliminary experiments showed that the half strength MS was more effective than MS for the tested cultivar (‘Yaghooti’). Therefore, this medium was used to further improve the efficiency of micropropagation rate by testing salicylic acid (SA) at 0, 2, 4, 6, 8 and 10 μM added to culture medium. SA up to 8 μM improved morphological, chemical and biochemical parameters whereas, 10 μM had negative effects on recorded parameters. The most appropriate level of SA was 6μM which increased shoot fresh weight (24%), root fresh weight (27%), shoot length (28%), root length (54%), reducing sugars (46%) and also enhanced the activity of catalase (50%), guiacol peroxidaes (32%), and ascorbate peroxidase (73%) compared to the control. However, the oxidative parameters including malondialdehyde (MDA), other aldehydes and hydrogen peroxides were strongly reduced by 36%, 42% and 27%, respectively when 6μM SA was used. Thus, it is concluded that the half strength MS is not an appropriate medium for micropropation of tested cultivar as the cultures are under stress and 6 μM SA could effectively remove the stress and increased the efficiency rate of micropropagation.

Cold stress is a major environmental factor affecting agricultural productivity of crops. Recent advances have revealed key components of stress signal transduction pathways that enhanced stress tolerance in plants. Considering nitric oxide (NO) is a ubiquitous bioactive molecule that plays a central role as a signal in plant responses to biotic and abiotic stress. In this research the effects of sodium nitroprusside (SNP) (as a NO releasing compound) and arginine (Arg) (as NOS substrate) pretreatment on alleviation of chilling stress were investigated and compared in tomato plant. In this study 3-week-old plants pretreated with SNP 100μM and arginine 5μM for 10 days and then subjected to 5°C for 6 h. Finally lipid peroxidation, Hydrogen peroxide content and activity of CAT, APX and GPX enzymes were investigated. Results showed that, SNP and Arg pretreatment declined the lipid peroxidation and hydrogen peroxide content. In addition the activity of GPX and APX increased in plants which were pretreated with SNP and Arg while CAT activity increased only in Arg pretreatment. It seems that Arg as a NO precursor, to produce other products such as polyamines and proline had a more effective role than SNP pretreatment.