مجله علوم و فنون باغبانی ایران
سال شانزدهم شماره 4 (زمستان 1394)

Strawberry (Fragaria × ananassa) has high nutritional value that can be used freshable and processed. Nowadays¡ fertilizers play an important role in increasing the yield and quality of fruits and vegetables. In this study¡ effect of different levels of humic acid (0¡ 20 and 40 mg l1)¡ zinc sulphate (0¡ 50 and 100 mg l-1)¡ and boric acid (0¡ 50 and 100 mg l-1) on quantitative characteristics of fruit and increase of yield of „Camarosa‟ strawberry were investigated. Strawberry plants were sprayed by chemicals in two stages of 30 days after planting and beginning of blooming stage. The experimented layout was 7x2 factorial in a completely randomized design with four replications. The results showed that application of chemical at both stages¡ increased weight of primary and secondary fruit¡ number of their achenes¡ diameter¡ and length of fruit but beginning blooming stage was very effective compared with 30 days after planting stage.Total yield was significantly increased by all treatments compared to control treatment at both stages of application¡ specially at beginning blooming stage. Also¡ the highest average of fruit weight and yield observed at beginning blooming stage. In general¡ 40 mg l-1humic acid¡ had the highest effect on improving of fruit quantitative characteristics.

Peach has high nutritional value that can be used fresh-able or processed. This study¡ was conducted to examin the effects of different levels of methyl jasmonate (0¡ 100 and 200 mg l1)¡ salicylic acid (0¡ 150 and 300 mg l-1)¡ and their interactions on growth¡ yield¡ fruit quality at harvest time and postharvest quality and shelf-life of „Elberta‟ peach. Thus¡ trees sprayed by treatments in two stages of green tip and pink tip of bud¡ in a split-factorial experiment within a randomized complete block design with 4 replications. At harvest time¡ many of the biochemical and quantitative characteristics of fruit such as ripening delay¡ firmness¡ total soluble solid¡ organic acids¡ pH¡ vitamin C¡ fruit water percentage¡ dry weight percentage of fruit¡ reducing sugars¡ anthocyanin¡ phenol content were studied. Generally¡ the results showed that spraying at both stages increased biochemical and quantitative characteristics of fruits compared with control and between treatments. Methyl jasmonate (200 mg l-1) combined with salicylic acid (150 mg l-1) had the highest effect on improving quantitative characteristics of fruits. Trees treated with chemical had shown greater growth improvement of fruit quaility compared wit pink tip stage at green tip stage.

Plane tree is one of the major tree used in urban landscapes of Iran. One of its serious problem is chlorosis and leaf abscission in many parts of the country. The current investigation was conducted to evaluate the effect of inoculation of plane trees (Platanus orientalis L.) with mycorrhizal fungus on response of plane trees in two years (2011 and 2012). An open field experiment conducted based on a randomized complete block design with 4 treatments and 6 replicates in Isfahan University of Technology. Treatments were as follwoings: livestock manure¡ chemical complete fertilizer¡ manure fertilizer mycorrhiza fungi and control (no fertilizer). The results showed that inoculation of plane trees with mycorrhizal fungus caused singnificant increase in most growth and physiological indices such as growth of current season shoots¡ total soluble sugar content¡ chlorophyll content¡ photosythetic indices and stomatal pattern ( diameter and number of open stomata).¡ To sum up the results revealed that inocultion of plants with mycorrhizal fungus¡ improved plants growth accordingly through its positive influence on stomata behavior¡ chlorophyll content and subsequently increase in photosynthesis.

Global warming and drought are the main causes of reduction in the production of fig in Iran. The situation is worse in dry farming areas. „Sabz‟ fig cultivar, which is mostly grown in dryland conditions in Fars province, has been afflicted by drought stress during the past few years. The aim of this experiment was to increase tolerance of fig trees to drought stress by foliar application of KCl and K2SO4. To this end,„Sabz‟ fig cultivar trees in Bidbokhoon sector of Neyriz town in Fars province were foliar sprayed with K2SO4 and KCl (0, 1.5 and 3%) in early growth season. Results indicated that application of K2SO4 and KCl at the rate of 3% increased potassium content, maximum quantum efficiency of photosystem II, total phenol, anthocyanin, carotenoid, protein and proline content in fig leaves and decreased superoxide dismutase and ascorbate peroxidase enzymes activity. The application of K2SO4 and KCl at the rate of 1.5% did not significantly affect the measured characteristics. Generally, the application of potassium sulphate and potassium chloride at the rate of 3% caused an increase adaption of fig trees against environmental stresses and there was no difference between the use of potassium sulphate and potassium chloride.

In order to study the effects of hydrogen peroxide (0¡ 100¡ 300¡ 500 and 700 µM) and sucrose (0 and 2%) on the vase life and water relations of cut rose flower cv. Candy¡ a factorial experiment was carried out based on a completely randomized design with 3 replications. In this experiment parameters of vase life¡ solution uptake¡ stem relative fresh weight¡ leaf stomatal conductivity¡ leaf relative water content and membrane stability index of petal cells were evaluated. Application of 500 and 700 µM hydrogen peroxide increased significantly vase life of cut rose stem in comparison with other treatments so that 700 µM increased vase life 12 days compared to control. The effect of 700µM sucrose 2% had a most significant effect on increasing solution uptake and stem relative fresh weight compared to other treatments. Leaf stomatal conductance decreased by increasing hydrogen peroxide concentration. Lowest amount was related to 500 and 700 µM of hydrogen peroxide treatments alone and with 2% sucrose. The highest amount of leaf relative water content and petal cells membrane stability index was related to H2O2 700µM treatment. In conclusion¡ the results showed that hydrogen peroxide treatment alone at highest concentration (700µM) increased vase life and with sucrose 2% improved solution uptake and stem relative fresh weight¡ as well as it caused a decreasing effect on leaf stomatal conductivity with keeping leaf relative water content and petal cells membrane stability index.

Unlike conventional micropropagation method¡ using bioreactors in large scale results in low production costs. Capitulum explants were grown in solid media¡ there after¡ regenerated shoots were transfered to Modified MS medium supplemented with different levels of BAP2¡ BAP (0.5¡ 1¡ 2¡ 3¡ 4 mg l-1) in combination with 0.1 mg l-1 IAA was used for proliferation stage in solid media in complatly randomized design with 4 replications. The results showed that BAP at concentration of 4 mg l-1in combination with 0.1 mg l-1 IAA caused the highest multiplication rate in solid medium. Multiplication rate in temporary immersion bioreactor (TIB) system was done as complatly randomized dosign with 3 replications with different times of immersion (2¡ 4 and 6 times daily¡ each time lasted 2 minutes)¡ supplemented with IAA (0.1 mg l-1) and BAP (0.5¡ 2 and 4 mg l-1)¡ and also in MMS solid medium supplemented with IAA (0.1 mg l-1) and BAP (0/5¡ 1¡ 2¡ 3 and 4 mg l-1). The result showed that 2 times of immersion had the highest shoot quality¡ but 4 times treatment showed the highest average number of regenerated shoots (25.1)¡ leaf number (8.06)¡ plantlet height (3.8) and fresh weight of regenerated mass (7.06)¡ and was considered as the best treatment of immersion in TIB. In TIB 2 mg l-1 BAP in combination with 0.1 mg l-1IAA had the highest amount of multiplication rate¡ and 0.5 mg l-1BAP in combination with 0.1 mg l-1IAA showed the best shoot quality than in solid medium. Overall¡ TIB could be used as an efficient and economically viable system in micropropagation of Gerbera.

To investigate the effects of exogenous application of ascorbic acid and salicylic acid on some biochemical characteristics of Zinnia (Zinnia elegans cv. Dreamland)¡ an experiment was conducted at research greenhouse of Faculty of Agriculture¡ Lorestan University¡ Iran in 2014. The experiment was done factorially based on a completely randomized design with four replications. Factor A was salinity with four levels (0¡ 30¡ 60 and 90 mM NaCl) and factor B was foliar application with three levels (water as a control¡ 1 mM ascorbic acid and 1 mM salicylic acid). Zinnia seeds were directly planted in pots¡ and after plant establishment¡ NaCl treatments were applied through irrigation and foliar application was done weekly. The results showed that with increasing salinity¡ catalase (CAT)¡ peroxidase (POD) and ascorbate peroxidase (APX) activity¡ proline and malondialdehyde (MDA) content increased. As well as¡ chlorophyll content decreased with increasing salinity. Foliar application of ascorbic acid and salicylic acid increased antioxidant activity¡ proline and chlorophyll content¡ and decreased MDA in plants treated with NaCl¡ compared with control plants. According to the results¡ foliar application of ascorbic acid and salicylic acid could effectively increase plant survival and growth under salinity stress through preventing the negative effects of free radicals¡ increasing antioxidants activity¡ photosynthetic pigments and osmolytes¡ and reducing lipid peroxidation and caused better survival of plants under salinity stress.

To study the effect of glycine betaine applicaion on accumulation of some osmolyte compounds in leaf and root of Qazvini Pistachio (Pistacia vera cv. Qazvini) under different salt stress levels¡ a greenhouse experiment was conducted based on completely randomized design (CRD) as factorial with two factors of salt stress (NaCl) at four levels (0¡ 50¡ 100 and 150 mM) and glycine betaine at three levels (0¡ 50 and 100 mM). Glycine betaine was applied at three stages: 1) 14 days after seed sowing at 4-leaf stage 2) 35 days after seed sowing 3) 55 days after seed sowing (10 days after stress commencement). Results showed that salt stress caused a reduction in total dry weight¡ leaf chlorophyll and carotenoids content and the less reduction was observed in seedlings sprayed with glycine betaine. Osmolytes concentration (soluble carbohydrates¡ proline and glycine betaine) were increased with increasing of salt stress level. Use of glycine betaine resulted in raising of internal content of it (leaf and root) and this raising was maximized under the highest level of salt (150 Mm) and glycine betaine (100 mM). Results of this experiment indicated the highest level of proline content¡ total soluble carbohydrates¡ sucrose and glycine betaine were observed when seedlings were exposed to 150 mM NaCl. Use of glycine betaine (especially at 100 mM) resulted in a lower content of proline¡ total soluble carbohydrates and sucrose in treated seedlings in comparison with non-treated seedlings. Proline was the most responsive osmolyte in leaf and roots in comparison with the others under salt stress condition.

In order to examine the influence of salisylic acid and chelated magnesium sulfate on growth indexes of pear cv. Louise Bonne in the ecological conditions of Qazvin province¡ a test was conducted in the RCBD with three replications and ten treatments on mature ten year old trees being grafted on seedling rootstock¡ in 2013. The treatments of magnesium sulfate were made in three levels (0¡ 0.5 and 0.7 g l-1) and salisylic acid in the three levels (0¡ 0.1 and 0.5 g l-1). The studied characteristics are included chlorophyll¡ leaf relative water content¡ current growth¡ specific leaf area and specific leaf weight. The results indicated that salisylic acid and chelated magnesium sulfate significantly affected on the chlorophyll amount and specific leaf weight. The LSD indicated that chlorophyll amount and specific leaf weight increased with using chelated magnesium sulfate and the highest amount of these indexes was observed in the treatment of chelated magnesium sulfate with maximum concentration and the lowest chlorophyll amount observed in the treatment of salicylic acid with minimum concentration. Also¡ the highest amount of relative water content was allocated to the combination of salicylic acid (0.5 g l-1) and chelated magnesium sulfate (0.5 g l-1) treatment.

Selecting frost tolerant cultivars and understanding the mechanisms of frost tolerance¡ can greatly reduce the amount of frost damage to the olives. Although the olive tree is classified among the most frost-hardy of the subtropical fruit trees¡ olive cultivars may differ in frost tolerance due to the differential survival of their specific organs. The purpose of this study was screening of different Olive cultivars for frost tolerance by means of ion leakage¡ potassium ion leakage¡ and amount of starch¡ soluble sugars¡ proline¡ and phenol in the separated leaves. In this experiment¡ leaf materials were exposed to frost temperatures (0¡ -3¡ -6¡ -12 and -15°C) for one hour and then several factors were measured. Results indicated that „Zard‟ and „Dehghan‟ possess the highest amount of soluble sugars¡ proline¡ phenolic contents and the lowest starch contents¡ ion leakage and potassium ion leakage percentage. In conclution¡ Zard and Dehghan cultivars were the most resistant cultivars and Drak¡ Dakal and Shiraz were the most sensitive cultivars to freezing in the range of investigated temperatures.