Iranian Journal of Horticultural Science
Year:2008 | Volume:39 | Issue:1|Papers Count:16

Considering the positive effects of silicon on salinity resistance by some agricultural plants, an investigation was conducted with a completely randomized design of three replications. The main objective was to determine the effect of silicon on nutrient content and nitrate accumulation in lettuce. Electrical conductivity was adjusted at 3 mmhos/cm through addition of NaCl. Silicon was added through addition of a silicate compound in the ratio of 0, 0.5, 1.0 and 2.0 mMilit. Mean analysis showed that calcium and magnesium contents of lettuce were increased in 0.5 mM L-1 treatment while a higher amount of silicon decreased the amount of calcium, magnesium and phosphorus. Increasing of Si up to 2.0 mM L-1 increased the amounts of potassium, total nitrogen and nitrate in the plant, whereas the amount of Na was decreased through this addition of silicon.

Resveratrol (5, 3, 4'- trihyroxystilbene) is a valuable aromatic compound administered in prevention of cancer, heart and vascular diseases in human. This compound was extracted from leaf and fruit tissues of two Iranian.grape cultivars (Rajabie Sefide Shiraz and Keshmeshie Ghermez) through using a general extraction method with some modifications and quantitatively analyzed through High Performance Liquid Chromatography (HPLC). Resveratrol content in leaf and fruit of Rajabie Sefide Shiraz cultivar was more than that in Keshmeshie Ghermez and its content in the. Fruits of either cultivar were observed to be more than that in their leaves. The accumulation of Resveratrol at the early stages of fruit growth (4 weeks after full bloom) was higher than that at the subsequent stages of fruit growth and development (8 weeks after full bloom and complete ripening) in either one of the cultivars, so that the amount of this compound was gradually decreased from the beginning of fruit set to a complete stage of growth and development, being at its minimum when the fruits were completely rip. In other words, the accumulation of this compound followed a decreasing trend from the beginning of fruit growth and development to the ripening stage being minimum when the fruits were completely ripened. Leaves and fruits of either cultivars were exposed to UV ray (254 nm wavelength), the rate of resveratrol being measured following the treatments. It was observed that the amount of this compound was significantly increased in treated samples as compared with control. It was observed that the amount of this compound significantly increased in treated samples as comparison with control. The fruits in both cultivars responded better to the treatments 4 weeks after full bloom. The rate of resveratrol accumulation decreased at the subsequent stages, so that a minimum accumulation occurred in the course of the fruits becoming completely ripe.

Broccoli (Brassica oleracea L. cv Premium crop) florets were packaged using two types of polymeric films (polyethylene, LD & polypropylene -cast)and then stored at 1°C for 18 days to study the effect of passive and active MAP (1.5%02+7.5%CO2) on preservation of quality and nutritional value as compared to non-wrapped control florets. During storage, weight loss, rate of ethylene production, quality, fermentation products, vitamin C, chlorophyll, pH and titrable acidity were assessed and estimated every 3 days. Results revealed that deterioration occurred quickly in control broccoli, manifested mainly by weight loss, firmness reduction, and chlorophyll degradation and yellowing. Conversely, in those florets packaged under MAP (especially for polypropylene), ethylene production as well as all other changes related with loss 9f quality was significantly reduced. This situation prolonged storability up to 18 days with high quality attributes as well as vitamin C preservation. At the end of the storage period, broccoli gradually developed slight to moderate alcoholic off-odors accumulating ethanol, and acetaldehyde in the tissues.

Iran is the center of origin as well as variation for pomegranate (Punica granatum 1.). Also, Iran is one of the most important countries in the world in terms of pomegranate culture and production. Monitoring morphological and physiological changes which occur during fruit growth and development is an important determining in orchard management decisions. The aim of the present research was to study fruit physicochemical changes of pomegranate cv. 'Malas-e-Torsh-e-Saveh' during its growth and development. The results indicated that pomegranate fruit growth and development during the growing season follows a single sigmoid growth pattern. In addition, length, diameter, volume, fresh weight, dry weight, 100 fresh aril weight, aril percent, juice percent, pH, total soluble solids as well as flavor index increased during fruit growth and development. Meanwhile titrable acidity, fruit peel thickness, and percent as well as fruit length to diameter ratio decreased during its growth from fruit set until maturation and full ripening. There was a correlation observed between total soluble solids and titrable acidity which could be used for a determination of optimum time for fruit harvest. In general, 'Malas-e-Torsh-e-Saveh' is a late maturing cultivar whose fruit diameter and length become equal at full fruit ripening stage with its fruit consisting of 68% aril (with 68% aril juice) and 32% peel. At this stage, total soluble solids, titrable acidity, pH and flavor index were 18%, 1(mg/100g), 3.40-3.50 and 18 respectively. The results obtained from the present research work could be effectively used for a better management of pomegranate cv. 'Malas-e-Torsh-e- Saveh' orchards.

Alstroemeria (Alstroemeriaceae), commonly called the Peruvian Lily or Lily of the Incas, is one of the most important cut flowers throughout the world, commonly propagated through rhizome splitting. Because of such impediments as low multiplication .rate, time consuming process and high risk of carrying and transfer of viral diseases, in vitro propagation techniques based on rhizome meristem culture have been on the developmental stages nowadays. In this experiment, lateral and terminal buds of rhizomes (4-6mm) were cultured on solidified MS medium containing 30 g/J of sucrose supplemented with different concentrations of BAP and NAA after surface sterilization and were then subculture every three weeks. Some growth factors as number of rhizomes, shoots and roots, length of shoots and roots were studied. Explants started to grow after three weeks. The greatest number of shoots was obtained in the medium supplemented with 1.5 mg/l of BAP and 0.2 mg/l of NAA. Furthermore, the results showed that higher concentrations of BAP caused a reducing length of shoots due to a decrease in apical dominance; also it was shown that the presence of a low NAA concentration in the medium was necessary for primordial shoot and rhizome growth. Consequently, the medium containing0.5mg/l of BAP and 0.2mg/l of NAA, producing on the average, 4.1 rhizomes along with 2.62 shoots per explants resulted in the most suitable hormonal treatment for micro propagation of Alstroemeria cv. "Fuego".

To determine the effect of pot level and nutrient leaching on albinism disorder in strawberry (Fragaria ananassa Duch cv 'Camaroso') cultivated in perlite substrate an experiment was conducted in 2006. Yield was determined three times (January-February, March-April and May- June). The results indicated that plants located in an upper position showed more albinism (40.42%) which could be related to nitrogen and potassium leaching as well as a decrease in light intensity. Albinism fruits had higher nitrogen (1.4 mg/g) and potassium (2.14 mg/g) and lower calcium (0.13%) contents, the ratio of N/Ca and K/Ca being higher as compared with those in the normal fruits. Former plants fruit were smaller resulting in lower yield. Early fruits (January-February) showed the most albinism and the highest nitrogen (1.29 mg/g) as well as potassium (2.05 mg/g) contents. Albinism was decreased (19.55%) in the storage organs at the end of harvesting season because of decrease in nitrogen and potassium. The interaction effect between harvesting time and pot level was to be not significant.

Black cummin, Bunium persicum (Boiss) is a native medicinal plant of Iran with a considerable distribution throughout the country. Regarding the necessity of a thorough study towards domestication of this valuable medicinal plant, in this research, genetic diversity of twenty four populations of black cummin was studied using RAPD markers. Fifteen RAPD primers of the highest level of reproducibility of template DNA and polymorphism among the banding pattern of the samples were selected for the study of populations. Two hundred and twenty eight bands were produced from among which one hundred and ninety six (86%) were polymorphic. Average polymorphism obtained for each RAPD primers was 13.97. Jaccard's similarity coefficient was used for an assessment of genetic similarities among populations. Estimates of genetic similarity based on the polymorphic bands ranged from 0.19 to 0.75 with an average of 0.53. Cluster analysis was performed based on similarity matrix and an application of UPGMA method. In the resultant dendrogram, maximum similarity was detected between Sirch and Jiroft-Darzin while minimum similarity observed between Barn, and Sistan & Baluchestan populations, the results showed a high level of genetic diversity among investigated populations, while also indicating that RAPD technique is an efficient tool for assessing genetic diversity in black cummin.

The production of oxygen radicals in plants under salinity stress conditions in an important factor for a diminishing of photosynthesis and a cause fir a decrease in later vegetative growth. In order to study the effects of antioxidants and salinity stress on photosynthetic characteristics and growth in olive, an experiment was conducted in the research greenhouse of Tabriz University in 2007. In this experiment ascorbic acid (2mM) and reduced glutathione (3mM) as well as control combined, with two NaCl concentrations, were factorially applied on one year old olive plants. The experiment was carried out as a completely randomized block design with four replications. Results indicated that ascorbic acid had a great effect on photosynthesis in the non-saline treatment in comparison with others. Exogenous application of ascorbic acid caused an increase in stomata conductance, respiration, chlorophyll and such vegetative traits as leaf area ratio and leaf weight ratio. On the other hand, this treatment led to decrease in leaf water content, specific leaf area and leaf water content per unit area. Some such traits as net photosynthesis, stomatal conductance, respiration, leaf area ratio, chlorophyll shoot water content, shoot water content, leaf weight ratio and peroxides activity were significantly decreased in salinity treatment. Other traits as well (leaf water content, specific leaf area and leaf water content per unit area) were increased in the salinity treatment with regard to these results, ascorbic acid was shown to exert positive effects in improvement of photosynthesis and growth of olive under saline and non-saline conditions in comparison with reduced glutathione, and with control.

Grapevine is one of the very important fruit crops in Iran the fruit of which is used as table grape and/or raisins. In this study, some genetic parameters (phenotypic and genetic correlation, heritability and repeatability), of some important traits in table grape (date of ripening, weight, length and width of berry as well as attachment to cluster strength) were evaluated. Results showed high heritability for some traits; heritability being 0.65, 0.67 and 0.54 for weight, length and width of berry respectively. Heritabilities were 0.60, 0.29, 0.37 and 0.28 for date of ripening, °Brix, acid content and their ratio respectively. Results regarding coefficient of correlation showed that correlation between berry weight and °Brix as well as acid content was highly affected by genetic factors while phenotypic correlation being rather low. Repeatability of traits was observed as high during the two years. It was 0.98 for berry colour, however, it was very low for traits related to fruit juice (TSS, TA and TSS/ TA).

An orchard experiment was conducted at Gonabad Pistachio Production Station., Khorasan, Iran (1998-2003). In some pistachio trees, especially in cv.Owhadi, leaf marginal choruses were already observed. Then, gradual drying of leaves extended to the leaves' centers up to midsummer. With respect to salinity problems, some researches were done. Two orchards of pistachio known as No.6 and No.7, were irrigated with waters of different electrical conductivities (ECiws) including ECiwl=7.45 desisimensl meter (dSm-1) and ECiw2=11 dSm-1, respectively. The cultivars (cvs.) of Badami-sefid and Owhadi, budded on seedlings of Badami- Riz formed the scion-rootstock combinations. Experiments were done in the from of RCBD with repeated measurements. In block 1 of orchard6, which had been previously increased in salinity, each tree received two times N fertiliiation in 2000. Nevertheless, in blocks of two orchards, each tree received a complementary fertilization in 2001. Experiment 2 with more cultivars was conducted during 1990-1999 in one of the pistachio orchards with ECiw of 10.29 dSm-1 in Khaf district, Khorasan. The results of combined analysis in the case of experiment 1, in different years and orchards revealed that quantitative yield of cV.Badami-Sefid was significantly higher than that of cv. Owhadi. In conditions of this experiment, alternate bearing was an important problem in cv. Owhadi. Complementary fertilization increased the yield of pistachios in 2003, significantly. The ranges of Cl and especially Na ion accumulation in leaves of tolerant cv. (Badami-Sefid) was less than those in the sensitive one. In block 1 of orchard 6, Ca and Mg absorption by plants was significantly reduced. This cation competition caused the yield of that block to be meaningfully reduced. However, N accumulation in leaf tissues of sensitive cv. was considerable, too. The higher N fertilization of block 1 in orchard 6 caused the N content of leaf tissues in orchard 6 (especially in block I of this orchard) to be meaningfully higher. In orchard 7 cation competition of Na was more considerable. The effect of salinity was not so problematic as to suppress the absorption of phosphate. Through heading back of some sensitive plants, done beneath the union graft points, it was observed that salt sensitivity was due to cultivar (grafts). In experiment 2, quantitative yield of Owhadi was considerable and no leaf damaging was observed. In establishing new pistachio orchards in saline conditions, one had better put these genetic diversities into serious consideration.

The role of manure and urea on yield and some fruit characteristics of strawberry cv. Kurdistan were studied during 2002-2004 growing season. The experiment was a factorial one based on a randomized complete block design including four levels of urea (0, 50, 100, 150 kg/ha) and three levels of manure (0, 20, 40 t/ha) in three replications. The results showed that application of manure along with urea had a significant effect on total fruit yield, and prevention of weight, fruit decay as well as leaf specific mass. The total fruit yield in 100 kg/ha of urea treatment was higher than that for the other treatments, but there were no significant differences observed with 50kg/ha of urea + 20t/ha of manure. Also the weight per fruit in 50 kg/ha of urea + 20t/ha of manure was higher than that for the other treatments. The lowest post harvest fruit decay was observed with an application of 50 kg/ha urea + 20 t/ha of manure. Increasing the amount of urea increased fruit decay. Leaf Specific mass in the 50 kg/ha of urea + 20 t/ha of manure was higher than that for the other treatments. There were no significant differences observed in treatments' acidity and TSS. The results showed that an application of 50 kg/ha of ureat+ 20 t/ha of manure was the most suitable treatment under the conditions.

In this regard, the morphophysiologic and anatomic characteristics of six Olive cultivars (Nabali, Feshomi, Arbequin, lard, Gordal and Roghani) were investigated under drought. Experiments were designed based on factorial and complete block random plot with two control treatments, -1.5 MPa stress and three replicates. The investigated factors were as follows: leaf area, specific leaf area, leaf angle with stem, leaf numbers, length and number of branches, the number of stomata, think diameter, relative water content (RWC), leaf water potential (LWP), water saturate deficiency (WSD) and water content (WC). In this study, no significant differences were observed in leaf area and specific leaf area between control and stress treatment. In leaf angle with stem the difference was found significant. In Nabali cultivars the change in leaf angle with stem was less pronounced compared with other cultivars. Leafs numbers decreased under drought conditions, but leafs number in Nabali and Arbequin cultivars in comparison to other cultivars, shows a higher efficiency of photosynthesis in anabolism in these cultivars. The number of branches and consequently, the length of branches decreased under drought stress. Arbequin and Nabali cultivars were less affected by drought. In the study the stomata density increases under drought stress. An increase in stomata density was appeared in Gordal and Roghani cultivars. Drought resistance observed in Nabali and lard cultivars due to the high level of leaf water potential, an increase in relative water content, the low level of water saturation deficiency and water content.

In order to investigate the effects of substrate and spawn levels on growth and development of Florida oyster mushroom an experiment was conducted in 2005 at the laboratory of the Department of Horticulture, Agriculture Faculty, Shahid Chamran University, Ahvaz. The design of the experiment was a factorial one of randomized complete blocks of 3 replications. The two factors of substrate and spawn were conducted at three levels. Substrate consisted of sugarcane bagasse, wheat straw, and a mixture of sugarcane bagasse and wheat straw in a 1:I ratio. Spawn in three levels of 2.5, 4, and 5 percent were investigated. Traits determined consisted of days for taken to completion of spawn runners, pin heads as well as fruiting bodies formation, mushroom yields, dry wight, and protein content. The results showed that the effects of substrate and spawn levels on determined characteristics in total and at 1% level of probability were significant. A comparison of means with Duncan's New Multiple Range Test (DNMRT) indicated that dry matter and grown mushroom protein in sugarcane bagasse substrate treatment were higher than those in the other two substrates whereas mushroom yield on wheat straw substrate and in 5% spawn level was higher than that in the other treatments. The results also indicated that in these last treatments fruit body formation was significantly faster.

The effect of some treatments including preserving solution (20g L-1 sucrose plus 200 ppm 8-HQS), BA and TDZ (pulse or spray) with preserving solution were evaluated on senescence parameters and vase life of Rose cut flowers cv. Red Gant. Preserving solution, applying 25 mM BA with preserving solution increased solution absorbance and prevented the cut flowers from getting decreased in relative fresh weight (RFW), petal and leaf water content as well as carbohydrates. It also suppressed the degradation of chlorophyll and petal soluble proteins. Application of 25 mM BA with preserving solution showed a higher anthocyanin content as well as flower diameter comparison with preserving solution, but had the same result on vase life of cut flowers. Extension of vase life was not observed by use of cytokinins in comparison to preserving solution being used alone.

This research was conducted at the Agricultural College of Tehran University in 2005 to analyze the effect of use of cytokinin as well as of calcium on durability of rose (Illona cultivar). Cuttings were taken from rose biennial mother plants, then treated by Cytokinin of 0, 0.1,1 and 10 micromole per liter and Calcium of 0,10,20 and 30 milimole per liter. Cut flowers, after harvest, were kept in distilled water and under laboratory conditions. Some different traits such as senescence, relative water content, electroleakage, total protein, and the extent of peroxide and catalase activities in petal were assessed. The results showed that Cytokinin levels exerted significant effects on senescence, electroleakage, total protein as well as activity of antioxidant enzymes. Calcium levels had also significant effects on senescence percentage, relative water content, electro leakage and peroxide activities in petals. The treatment a4b4, i.e. the use of Cytokinin at 10 micro-mole and calcium with 30 mili-moles resulted in a significant decrease in senescence and a significant increase in electro leakage, catalase and peroxidase activities.

Seventeen Iranian shallot genotypes from Ashtian, Arak,' Boroujerd, Dashtearjan, Doshmanziari, Divandareh, Khomein, Khansar, Sepidan, Siakhdarengoon, Sahne, Kangavar, Koohrang, Koohmaresorkhi, Nahavand, Harsin and Yasouj areas were evaluated for their morphological traits. Corms were collected from the mentioned regions and planted based on a complete block design. Quantitative and qualitative traits, leaf length, width, diameter as well as leaf number, scape length and diameter, inflorescence diameter, number of flowers in inflorescence, floret peduncle lenght, and mean diameter, corm mean weight, number of cormlet(s), clustered corm percent, dry matter percentage as well as ash percentage of corm were assessed. Analysis of variance indicated that the studied genotypes significantly differed for all traits, except for leaf width and floret peduncle length. Khansar genotype had the highest corm diameter (62.05 mm), corm mean weight (140.45 g) as well as yield (1400.45 g/m2). Cluster analysis resulted in the genotypes being divided into three subgroups. Arak, Doshmanziari, Koohmaresorkhi, Khansar, Harsin and Nahavand genotypes were placed in the first group, Khomein, Yasuj, Boroujerd, Divandareh and Sepidan genotypes in the second, while Dashtearjan, Koohrang, Ashtian, Siakhdarengoon, Sahne and Kangavar genotypes in the third group. Results indicated that, Iranian shallot is completely different from the common shallot (Allium ascalonicum) species with a wide diversity that makes it a valuable genetic resource for breeding programs.