مجله علوم و فنون باغبانی ایران
سال شانزدهم شماره 1 (بهار 1394)

To study the interactive effects of arbuscular mycorrhizal fungus (Glomus mosseae) and Pseudomonas fluorescens (P52 strain) bacteria¡ on osmotic regulators and water relations of pistachio seedling (Pistacia vera cv. ‘Qazvini’) under drought stress¡ a greenhouse experiment was conducted using four levels of drought stress (100% Field capacity (FC) as control and 75¡ 50 and 25% FC) and four levels of biofertilizer (non mycorrhizal and non bacterial plants as control¡ mycorrhizal treatment¡ bacterial treatment and a mixed treatment of both) in a completely randomized design as factorial with four replications. The maximum of root colonization (49.6%)¡ leaf relative water content (64.8%) and proline (10.8 mg l-1) was observed in 25% FC. Water use efficiency increased in 50% FC (0.6 mg ml-1). Drought stress reduced the soluble carbohydrates in leaves (2245.3 mg l-1 in 25% FC). None of treatments had effect on proteins and phenolic compounds. According to the results obtained¡ pistachio plants provide resistance against drought with increase of proline and bacterial treatment increased proline content in 25% FC (13.4 mg l-1). In addition¡ effect of mycorrhizal treatment on leaf relative water content was positive (61.3%). Thus consolidated application of mycorrhizal fungus and Pseudomonas fluorescens bacteria is recommended for increasing drought resistance of pistachio.

This research was conducted to compare the effects of three planting dates (1 Dec¡ 21 Dec and 10 Jan) and three nutrition concentrations of Epstein (Full¡ 2/3 and 1/3) on yield and quality of strawberry fruit cv. ‘Selva’ in Ahvaz. Planting date had significant effects on yield and fruit quality parameters of strawberry¡ where maximum plant yield (160.77 g)¡ fruit TSS (8.83%)¡ TSS/TA ratio (12.18) were obtained at second planting date¡ and maximum flower number (29.67)¡ fruit number (13.67)¡ firmness (1.8 N) and vitamin C (57.29 mg 100g-1) were recorded at first planting date for plants which were fertigated with full Epstein solution. Delay in planting date resulted in reduced plant yield¡ fruit number¡ fruit set¡ acidity¡ vitamin C and TSS/TA ratio. The concentration of nutrient solution also affected most of yield and fruit quality parameters significantly but fruit volume and weight¡ florescence number¡ fruit set¡ fruit length and diameter were not affected. Based on obtained data¡ planting at both 1 and 21 December and full Epstein fertigation can be recommended for hydroponically production of strawberry fruit cv. ‘Selva’ in Ahvaz.

Yew (Taxus baccata L.) is a difficult-to-root plant and endangered species of Iran. It is important as a forest, medicinal and landscape species. A CRD based factorial experiment with three replications was conducted to evaluate the effects of Agrobacterium rhizogenes and auxins on adventitious root formation in stem cutting of Taxus bacata L. The factors included three Agrobacterium strains, A4, LB9402 and C58C2, NAA (0, 500 and 2500 mg l1) and IBA (0, 500, 2500 and 5000 mg l-1). Rooting, callusing, root length and number of main and lateral roots were significantly affected by Agrobactrium strains and auxins. The highest rooting percentage (90.66%) was obtained in treatment included A4 strain and IBA (5000 mg l-1) and NAA(2500 mg l-1). Remakable rooting (87.5%) was also found in the combination treatment of LB9402 and IBA and NAA.

To study the effects of salinity stress and rootstock on the vegetative indicies, echophysiological and biochemical charactristics of pomegeranate (Punica granatum L.) cv. ‘Gabri’, a factorial experiment was conducted based on completely randomized design with 0 and 70 mM of salinity levels of sodium chloride and calcium chloride (1:1) and three grafted treatments (‘Gabri’ non grafted as a control, ‘Gabri’/Tab -o- larz and ‘Gabri’/Malas -e- yazdi) with three replications. Salinity decreased growth indicies in grafted and non grafted plants so that the lowlest reduction of growth under salinity was observed in grafted plant. Althought no significant difference was observed between rootstocks. The used rootstocks in non stress condition reduced vegetative growth of scion and this reduction was higher in rootstock of tab -o- larz than rootstock of malas -e- yazdi. Also proline, soluble sugar and carotenoids contents of leaf increased in salinity stress so that the lowest level of proline, sugar soluble and carotenoids content were observed in non grafted ‘Gabri’ plants.Chlorophyll a, b and total, Fv/Fm and relative water content of leaf reduced in grfted and non grafted plants by salinity so that grafted plants had the lowest reduction of chlorophyll a ,b and total, Fv/Fmand relative water content of leaf. The results of present study showed that rootstock types affect the salt tolerant indices of scion such as relative water content of leaf and chlorophyll that was more evident in tab -o- larz rootstock.

For micropropagation of two endangered genotypes of fig (Dehdez and Bargchanari)¡ nodal segments were used as explant. For bacterial decontamination¡ the explants were treated with different concentrations of antibiotic Ceftriaxone (0¡ 50 and 100 mg l-1). In two separate experiments¡ the effects of BA and NAA in different levels were investigated on shoot proliferation using MS medium. The experiments were carried out as factorial test in complete randomized design. The secretion of phenolic substances was stopped when culture media were supplemented with 2 mg l-1 of activated charcoal. Bacterial contamination was fully controlled with 100 mg l-1 Ceftriaxone. The highest shoot number/ explant (4) were obtained in 8 mg l-1 BA in subculture of the second experiment. Generally¡ with increasing BA in culture media¡ shoot length decreased. Produced shoots were rooted in half strength MS supplemented with 1.5 mg l-1 IBA and then transferred to soil mixture. The survival rate was about 90%.

To study the impact of supplementary pollination with pollen suspensions enriched with boric acid on quantity and quality of pistachio fruit cv. ‘Owhadi’, an experiment was conducted with 6 treatments at two different locations. Parameters, including the fruit set percentage, dehiscent nut percentage, blankness percentage, deformities percentage, fresh and dried fruits weight and kernel, ounces, oil and protein percentage were measured. The results showed that the highest percentage of final fruit set and the lowest fruit drop was obtained with treatments containing 0.02% boric acid. The highest mean percentage of dehiscent nut was obtained with treatments containing 0.01% boric acid (SAB1). The least percentage blankness was obtained with treatments containing pollen and boric acid 0.02%.

In order to study, the correlation between leaf color and antioxidant activity of 21 coriander accessions, a completely randomized design experiment was carried in agricultural department of Shahid Chamran University during growing season 2012. After growth of plants, in harvesting stage four plants were selected randomly among three lines of each accession. The color characteristics were determined, and the leaves of each line were mixed together, one gram samples of fresh tissue for each replicate were used to measure the amount of chlorophyll a, b and total, carotenoeids, vitamin C, peroxidase and catalase. The results showed that the maximum amount of carotenoids and vitamins C observed in East Azarbaijan (10.45 mg 100 gr F.w.-1) and Khorassan 1 (0.90 mg 100 gr F.w.-1) accessions, respectively. The maximum peroxidase and catalase activities were found in the accessions of the Markazi 2 and Ahwaz respectively, with 2.74 µmol of hydrogen peroxide per minute per milligram protein. The positive correlation was observed between catalase with peroxidase, catalase with hue angle of leaves, brightness and color intensity, carotenoids and chlorophyll a, b and total. According to these findings, the corianders with dark green or very bright green leaves have a higher antioxidant contents.

In this research, the interactive effect of cadmium and mycorrhzal symbiosis was studied on growth, nutrients uptake and mycorrhizal colonization percentage in ‘Qazvini’ pistachio seedlings. The experiment was carried out based on completely randomized design as factorial with two factors of mycorrhiza at two levels (with or without mycorrhiza) and cadmium (0, 0.5, 1, 2, 4 and 6 mg l-1). Cadmium caused a reduction in vegetative parameters and increase in leaf abscission percentage. Nutrients uptake was also affected by cadmium where root P, Mg, Fe and Mn reduced. Stem Ca and Zn were increased primarily and then decreased. Leaf Zn, Stem and leaf Mn and root, stem and leaf Cd were increased. Moreover, mycorrhizal colonization of pistachio seedlings improved vegetative parameters under cadmium stress in comparison with non-mycorrhizal seedlings. Cd uptake and translocation was significantly higher in non-mycorrhizal seedlins in comparison with mycorrhizal ones. Mycorrhizal colonization percentage was increased with increasing cadmium levels. In conclusion, mycorrhizal symbiosis with ‘Qazvini’ pistachio seedlings in the presence of Cd, improved nutrients uptake like Mg, Fe and P and reduced Cd uptake and as a result, it reduced the toxicity effects of Cd on plants and maintained their growth.

Lisianthus (Eustoma grandiflorum) is an ornamental plant with beautiful flowers that has marketability and high economical values due to its qualitative chaacteristics. Micropropagation is a powerful tool for large-scale propagation of ornamental plants. In this research the lateral buds explants from lisianthus (‘Eco’ and ‘Mariachi’cultivars) were cultured on MS medium supplemented with 0¡ 0.5¡ 1¡ 2 and 2.5 mg l-1 of benzyl adenine and kinetin (KIN) to proliferation. This experiment was conducted using randomized complete block design (RCBD) with four replicates and each plot containing 3 explants. KIN (2 mg l-1) was the best treatment for traits such as new shoots¡ leaf number and wet weight for both cultivars. Increase of cytokinin concentration to 2.5 mg l-1 resulted in significant decrease in all studied traits. In the rooting experiment¡ among three auxins (NAA¡ IAA and IBA) the best treatment was 1.5 mg l-1 of IAA on ‘Eco’ cultivar and 0.6 mg l-1 NAA on ‘Mariachi’ cultivar on 1/2 MS medium for number and length of roots.

In this study, effect of CaCl2 treatment and spraying time were studied on quality, mineral composition and shelf life of apricot (Prunus armeniaca cv. ‘Jahangiri’). The experiment was conducted in a randomized complete block design with seven treatments at the experimental orchard of Horticultural Research Station of Kamalabad in Alborz (Karaj) province, Iran, during two years (2010 and 2011). Treatments were control tress (spraying with distilled water) and two concentrations of calcium chloride (0.5 and 1%), in three time (30, 38 and 46 days after full bloom). Fruits were stored at 0°C with 93 to 95% relative humidity. Fresh weight and dry weight, flesh fruit firmness, fruit volume, pH, total soluble solid (TSS), mineral concentration (Ca, Mg, N, K and P) were measured five times (at harvest time, 1st, 2nd, 3rd, 4th week of shelf life). Also, fruit wet weight loss was recorded at week 4 and compared with the fruit weight at harvesting. The results indicated that pre-harvest calcium chloride spraying of fruits had significant effect on all of studied parameters. Spraying with different concentrations of calcium chloride increased shelf life of apricot until 10 days with maintaining of quality. The best spraying time for increasing of fruit quality can be applied between 1 and 1.5 months after full bloom.

In this study, direct soamtic embryogenesis of two Iranian native orchid species Dactylorhiza umbrosa and Epipactis veratrifolia via protocorm explants was investigated. In Epipactis veratrifolia, paclobutrazol ( PBZ) (0, 0.025, 0.05, 0.075 mg l-1) in combination with 2,4-D (0, 0.05, 0.1, 0.2 mg l-1) and thidiozoran (TDZ) (0, 1, 2, 3 mg l-1) were tested in 1/8 MS as basal medium and PBZ (0, 0.025, 0.045, 0.065, 0.1, 0.125 mg l-1) in combination with BA (0, 0. 5, 1.5, 3 mg l-1) were used in FAST medium for Dactylorhiza umbrosa. The results showed that in E. veratrifolia, 0.025 and 0.05 mg l-1 PBZ and 1 mg l-1 TDZ had highest embryogenesis rate with producing 11.33 means of embryos per explants. In other species, 0.045, 0.065 mg l-1 PBZ and 0.045 mg l-1 PBZ in combination with 1.5 mg l-1 BA had highest embryogenesis frequency with 4 embryos per explants. This is the first report about positive effect of PBZ on somatic embryogenesis in both orchid species. The Plantlets were transferred to hormone-free medium after six weeks.

In this research, the effect of temperature pretreatment on callogenesis and gametic emberyogenesis resulting from anther culture of cucumber (Cucumis sativus L.) using a local variety of cucumber (Esfahani) and an Italian cultivar (‘Beta Alpha’) was investigated. In the first experiment, cold pretreatment (control, 4 and 10°C for two and four days) was considered as main plot and the two cultivars as sub-plot. In the second experiment, temperature (control, 30 and 35°C for two and four day) was considered as main plot and two cultivars as sub-plot. Results showed significant differences among the various types of temperature pretreatments for callogenesis and gametic embryogenesis resulting from anther cultures of two cucumber cultivars. In the first experiment, using 4°C cold pretreatment for 4 days showed the highest callogenesis and mean number of embryos per anther, in anther culture of Esfahani and ‘Beta Alpha’ cucumbers, respectively. In the second experiment, application of heat pretreatments of 30°C for 4 days, and 30°C for 2 days resulted in the highest callogenesis and mean number of embryos per anther in anther culture of Esfahani cucumber. Furthermore, heat pretreatment of 30°C for 2 days in Esfehani cucumber showed the highest direct embryogenesis.