مجله علوم و فنون باغبانی ایران
سال چهاردهم شماره 1 (بهار 1392)

The purpose of this study was to investigate the effects of zinc on cold hardiness of grapevine, cv. ‘Bidaneh Sefid’. Zinc sulfate at three concentrations of zero (control), 0.04 and 0.08 % were foliar sprayed on grapevines for five times during growing season. On Dec 25th and Feb 23rd, cane samples were prepared and analyzed for their content of carbohydrate, proline, protein and relative water. Samples also were treated at 0, -3, -6, 9, -12, -15, -18, -21, -24, -27 and -30 °C for three hours in a freezing chamber to be analyzed according to tetrazolium test and electrolyte leakage. Results showed that by increasing zinc sulfate, grapevine's relative water content reduced while amount of carbohydrate, proline, and protein increased. Treated grapevines by zinc sulfate (0.08%) revealed the lowest electrolyte leakage and the highest tissue survival. Positive significant correlations were found between results of LT50 calculated based on tetrazolium test and electrolyte leakage and carbohydrate, proline, and protein content of cane. It can be concluded that application of zinc sulfate could potentially increase cold hardiness of grapevine cv. ‘Bidaneh Sefid’.

In this experiment, the effects of storage temperature and pulsing treatment of ethanol on quality and postharvest storage life of Gladiolus grandiflorus cvs. ‘Ruse Supreme’ and ‘White Prosperity’ were studied. Effects of treatments on vase life, flower diameter, opening flower percentage, rate of flower opening, fresh weight, water absorption and apparent quality of cut flowers were investigated. The results showed that vase life of cut flowers of both cultivars increased at 2 and 4˚C compared to 25˚C. Flowers of both cultivars treated by 2% and 4% of ethanol, stored in 2, 4 and 25˚C showed significant increase in vase life, flower diameter and number of florets. The best apparent quality observed in flowers stored at 4˚C. The quality of flowers stored at 2˚C decreased due to chilling injury but improved with application of 2% of ethanol.

This research was carried out to investigate the effects of foliar application of zinc sulfate (ZnSO4) and potassium nitrate (KNO3) on qualitative and quantitative characteristics of fruit, and oil yield of 11-year old olive trees cv. ‘Amygdalifolia’ at the Kazerun Olive Research Station during 2007-2008 years. A factorial experiment 4×4 was arranged in a randomized complete block design with four replications. Treatments were four levels of zinc sulfate (0, 0.25, 0.50 and 0.75%) and four levels of potassium nitrate (0, 0.5, 1.0 and 1.5 %) applied alone and in combination at the beginning of second and third stages of fruit growth. On the bases of fruit growth curve, 45 and 120 days after full bloom respectively, were the beginning of metioned stages. The results indicated that high fruit volumes were obtained in 0.5% zinc sulfate and 0.5% potassium nitrate combination. Fruit weight was influenced by using of zinc sulfate and potassium nitrate and improved in comparison with fruits of control trees. So, the highest fruit weight was achieved in combination of 0.5% ZnSO4 and 0.5% KNO3. Zinc sulfate and potassium nitrate had significantly effect on fruit oil. Maximum oil percentage in dry and wet fruit weight were achieved by using 0.5% ZnSO4 + 1% KNO3 and 0.5% ZnSO4, respectively. Application of both zinc sulfate and potassium nitrate had some interaction effects on fruit phenol content and the highest phenol content of fruits was observed by using of 0.5% ZnSO4 + 1.5% KNO3. Therefore, for increasing fruit yield application of 0.5% zinc sulfate + 0.5 potassium nitrate can be suggested during second and third stages of fruit growth.

In recent years, the disorder of aril paleness known as arils browning or whitening through unacceptable consumption of pomegranate fruit has threatened the popularity of this fruit. In order to reduce this physiological disorder and improve the quality of fruit characteristics, an experiment was performed as factorial in randomized complete block design at Agricultural Research Center of Yazd. The factors of this experiment were salicylic acid in 3 levels (0, 0.3 and 0.6 mM) and potassium sulfate in 3 levels (0, 0.5 and 1%), that were sprayed over the trees in 2 stages (9 and 13 weeks after full bloom). Salicylic acid at 0.3 mM significantly increased Hue angle of aril and chroma of peel. The salicylic acid also enhanced the content of carotenoid. The lowest aril browning and the highest performance index (Pi) and total acid were observed by interaction of salicylic acid 0 mM and potassium sulfate 0.5%. The interaction of 0.6 mM of salicylic acid with 1% of potassium sulfate and also 0.3 mM of salicylic acid with 0% of potassium sulfate significantly increased total chlorophyll content. In addition phenolic compounds significantly increased by interactions of 0.3 mM and 0.6 mM of salicylic acid with 1% of potassium sulfate. All treatments also were increased ratio of variable to maximal fluorescence (Fv/Fm) and antioxidant activity.

Tulip (Tulipa L.) is one of the most important bulbous plant in the world that has a great spread over the country. This genus belongs to the lily family (Liliaceae) and contains almost one hundred species, from which 19 species exist in Iran. In this study genetic diversity among 18 Iranian tulip landraces of 6 species and 3 cultivars from T. gesneriana were investigated with RAPD molecular marker. From 14 used primers 69 bands were produced from which 67 bands showed polymorphic. All of the primers except BC14 showed large polymorphism to 100% and only BC14 showed 50% of polymorphism. Largest resolving power (Rp) was 4.28 in 13th primer. According to the results obtained from similarity matrix, the greatest similarity between T. gesneriana1 and T. gesneriana2 was 90% and the smallest similarity between T. montana3 and T. systola1 was 0.06%. By cluster analysis of obtained data with UPGMA method and Jaccard similarity coefficient with 35% of similarity, divided genotypes into 5 groups. Percentage of diversity was 57% between species and 43% within species; which shows a great inter and intraspecies variety among the studied genotypes. Such a great diversity in the modifying processes can be used as a useful modifying device.

Heat stress limits growth and productivity of plants. In this study, the effects of salicylic acid (SA) (0, 10 and 20 μM) on growth, biochemical traits (photosynthetic pigments, reducing sugars, malondialdehydes, other aldehydes, hydrogen peroxides and total proteins) and the activity of antioxidants enzymes (catalase, guiacol peroxidase and ascorbate peroxidase) in shoot and root; and also the survival rate of grape plantlets (cv. ‘Yaghooti’) under in vitro heat stress (25 and 40˚C) were investigated. At 25˚C, SA increased the level of hydrogen peroxides and had negative effects on growth, with the more sever effect at 20 μM. Heat stress (40˚C) reduced growth traits but increased the most biochemical parameters and the activity of antioxidant enzymes in shoot and root. Under heat stress, both levels of SA, especially 20 μM improved all measured parameters by reducing the hydrogen peroxidase level. However, under heat stress, SA treated plantlets survived, whereas all control plantlets died. It is concluded that SA can profoundly improve heat stress tolerance of grape plantlets under in vitro condition.

Potato is one of the important and strategic crops, which limiting factors such as diseases reduce its yield. The cytological studies of some of resistant and susceptible cultivars of potato to early blight disease, Alternarias spp. that is A. alternata and A. solani which are important in potato fields were considered. The cultivars were including: ‘Agria’, ‘Santé’, ‘Shepody’, ‘Milova’, ‘Boren’ and ‘Ramose’. Measured characters were the number of chromosomes, length of longest and shortest chromosomes, ratio of the longest to the shortest chromosome, the mean length of long arm to short arm of chromosomes, mean length of chromosomes and karyotypic symmetry in each cultivar. The results showed that the base chromosome number was 12 and 2n=4x=48 for the studied cultivars. The type of chromosomes in all studied cultivars were metacentric, sub metacentric and sub telocentric. Karyotipic analysis of cultivars using relative length of the shortest chromosome (S%), total karyotipic shape (TF%) and the difference in the range of relative chromosome length (DRL) was performed. All cultivars were relatively symmetric. Comparison of relative length of the shortest chromosome (S%) and the difference in the range of relative chromosome length (DRL) showed that the resistant ‘Ramose’ and ‘Boren’ cultivars, had the most symmetric karyotype, and the susceptible ones including, ‘Agria’ and ‘Santé’ had the least symmetric karyotype. The other cultivars including ‘Shepody’ and ‘Milova’ were located at intermediate state.

One of the major problems in olive industry is inadequate capacity of olive oil factories considering high volume of harvested olives. The aim of this research was to investigate the effects of post harvest environmental factors on olive oil quality. The experiment was conducted as factorial in completely randomized design with three replications. Factors including cultivar (‘Zard’ and ‘Roghani’), storage period (0, 15, 30 and 45 days) and storage temperature (4, 14, 24ºC and ambient temperature). Results showed that the effects of storage time, temperature and cultivar were significant on olive oil acidity. In both cultivars the acidity of olive oil obtained immediately after harvesting was in extra virgin value. Fruits stored at ambient temperature for 45 days had the highest oil acidity. Peroxide value was significantly different for all factor level, however it showed standard level for olive oil. The cultivar and storage temperature didnt significantly affect on polyphenoles content but increasing storage duration resulted decreasing in polyphenoles content.

Peppermint (Mentha piperita L.) from Lamiaceae family is one of the most important medicinal plants, used in food, sanitary and cosmetic industries. A field factorial experiment on the basis of randomized complete block design with four replications was carried out in Ferdowsi University of Mashhad in 2010-2011. In this study, the effects of three irrigation regimes (60, 80 and 100 percent of water requirements calculated by evaporation pan class A) and three mulch types (black plastic, wood chips and without mulch) were studied. The data obtained from each harvest analyzed separatly. The results of two harvest indicated that peppermint plants growth was better in the first harvesting than the second harvesting. Plants harvested in first harvesting had higher essential oil yield, but the highest percentage of essential oil (2.835 %v/w) and the highest essential oil yield (116.7l ha-1) was obtained from third level of irrigation (60%) with use of wood chips mulch at second harvest. The results of the essential oil analysis showed that menthol, menthone, iso-menthyl acetate, 1,8 cineole, menthofuran, neo- menthol, piperitone and limonene are the the main compounds with the greatest content.

In this research, 26 accesions of Cucurbita pepo sub pepo, were collected from differen Provinces of Iran in 2010 and their morphological diversity was assessed by UPOV cucurbita discriptor. Experimental plots were seeded on 3 June 2010, using a randomized complete-block design with three replications. Thirty nine traits (20 quantitative and 19 qualitative) were measured on all plants. Correlation analysis was performed to determine relationships between traits. Cluster and principle component analysis (PCA) were performed among populations using quantitative, qualitative and combination of quantitative-qualitative traits, separately and were compared with each other. Results indicated importance of qualitative traits is more than quantitative traits in both analyses. The first four principal component axes accounted for 66.75% of the total variation among the populations. The greater part of variance was accounted by flesh thickness, fruit shape, fruit diameter, fruit profile at blossom end, fruit profile at stem end, position of broadest part on fruit. Cluster analysis by UPGMA method using Gower genetic distance grouped 26 accessions into three groups.