Plant Productions
Year:2018 | Volume:41 | Issue:1|Papers Count:10

Background and Objectives Olive (Olea europaea L. ) trees are traditionally grown in relatively infertile lands being adapted to poor soils and irrigation. New olive orchards are usually established using mist-propagated plants derived from semi-hardwood cuttings. Although this propagation system is very efficient, from the economic point of view, shortening the juvenile period of plantlets is very important. Root colonization with mycorrhizal fungi can shorten the length of the juvenile period in olive plantlets, as inoculated plants can absorb the essential nutrient elements much better resulting in growth enhancement and faster development. Materials and Methods In this study, symbiosis effect of three mycorrhizal fungi on growth, chlorophyll content and the absorption of some nutrient elements in rooted cuttings of three olive (Olea europeae L. ) cultivars was investigated. The study was conducted through a factorial experiment based on a completely randomized design with three replications in the Research Greenhouse of the Department of Horticultural Sciences, Bu-Ali Sina University. The first factor included olive cultivars at three levels (Arbekin “ R1” , Conservalia “ R2” and Moharam “ R3” ), and the second factor consisted of mycorrhizal fungi inoculation at five levels (G. mosseae+G. intraradices) “ D1” , )G. hoi+G. mosseae( “ D2” , (G. hoi+G. intraradices) “ D3” , (Mixed three species) “ D4” and the control (non-inoculation) (D5). Results The results showed that almost all measured characteristics were affected by the treatments. The highest symbiosis percentage was observed in R2D2 and the least belonged to D5. Based on the result, symbiotic fungi made a significant increase in some growth indices including the height and diameter of the plants, leaf area and diameter and length of the branch. The inoculation also caused an increase in the fresh and dry weight of the root and aerial parts of the plants compared to the controls. Mycorrhizal fungal inoculation resulted in increasing the total, a and b chlorophyll contents in all treatments. This symbiosis caused a significant increase in the absorption of some nutrient elements such as K, Zn, Fe and P compared to the controls. Discussion The results of the present study showed that, mycorrhizal fungi colonization enhanced the uptake of essential nutrients by plants, leading to a greater root surface area and biomass. Both the growth and nutrient content of the mycorrhizal fungi colonized olive plants were increased. It seems that mycorrhiza increases the absorption of water and nutrient elements from the soil through the further development that results in increasing leaf photosynthesis and ultimately increasing the plant growth.

Background and Objectives Salinity and salt accumulation in the soil surface is one of the most important abiotic stresses that limit agricultural crop production in the arid and semi-arid regions of Iran. Thus, finding an alternative production technique or materials to alleviate stress condition is a research priority. One way to decrease the harmful effects of salinity is the foliar application of some chemicals such as Gamma-amino butyric acid (GABA) to increase plant tolerance to salinity. GABA is often accumulated in plants in response to live and non-live stresses such as drought, salinity, oxygen deficit, heat shocks and contamination of pathogens. Materials and Methods The current study was carried out to monitor the GABA effects on tomato physiological changes under salinity stress. The plants were grown in hydroponic system and received 0 and 50 mM NaCl as control and salinity stress, respectively. GABA at three concentrations 0, 10 and 20 mM was applied as a foliar application in either control or salinity treatments. Physiological characteristics of relative water content (RWC), membrane stability index (MSI), proline, total soluble protein (TSP) and enzymes activity, chlorophyll a, chlorophyll b, total chlorophyll and total soluble carbohydrates (TSC) were measured. Results The results showed that salinity stress and GABA were effective on the physiological characteristics of tomato. GABA can increase the tolerance of plants to environmental stresses, including salinity stress. MSI, chlorophyll a, total chlorophyll, carotenoids in salinity treatments were lower than control while TSC, proline, peroxidase and SOD increased. RWC, MSI, proline, TSC of GABA treated plant were greater than untreated in either salinity or control conditions. Also, SOD and peroxidase activity elevated in GABA treated plant under salinity stress. Discussion GABA increased antioxidant capacity in the plant and thus might eliminate radicals and prevents the destruction of cell membrane tissue, including the chloroplast membrane. In general, the results showed that in salinity stress conditions, GABA application as a compatible osmolytes might improve the tomatoes physiological performance and alleviate salinity stress.

Background and Objectives As a source of alkaloids, Poppy (Papaver somniferum L. ), is one of the most important plants in the field of pharmaceutical industry. Various methods including use of elicitors, adding precursor, optimizing culture, culture of hairy roots and its metabolites engineering are used to increase the production of secondary metabolites in plant cell cultures. In recent years, cultivation of hairy roots, to the production of valuable metabolites in a number of species of medicinal plants, has taken on commercial scale; but in most cases, this technique produces low amount of alkaloid in commercial scale. Hence, it is needed to optimize the production rate using biological and nonbiological elicitors. Materials and Methods This experiment was conducted in 2015 in biotechnology laboratory of Lorestan University, Khorramabad, Iran. Sterile explants were prepared from seedling and were then inoculated with Agrobacterium. Inoculated explants were kept in a dark condition for 2 days and then washed and transferred to glasses containing ½ MS medium complemented with cefotaxime. Finally, the glasses were kept in tissue culture room until production of hairy roots. The produced hairy roots were used as explants for elicitors' experiments in flask containers. In this study, in order to increase biomass of hairy roots, 4 types of elicitor treatments (salicylic acid, silver nitrate, copper sulphate and yeast extract) were evaluated in separate experiments based on a completely randomized design with 3 replicates. Results Confirmation of transgenic hairy roots was tested by PCR using the rolC gene primers to ensure the removal of bacteria from the produced roots. Results of PCR products were separated by electrophoresis and expected fragments were observed in gel. The results showed that the concentration of 5. 0 mg/mL of yeast extract elicitor had the most impact on morphological traits. Totally, results showed that biotic elicitors had better effects in comparison to abiotic elicitors. Also, high concentrations of elicitors in all biotic and abiotic cases had a negative impact on biomass of hairy roots. Discussion It was shown that biotic elicitors had better effects than abiotic elicitors. The remarkable result of this study was that the high concentration of elicitors had negative effects on biomass hairy root production in poppies plants. It seems that bio-active compounds elicitors induce the plant responses but high concentration of biotic and abiotic elicitors may cause cell death and browning of hairy root tissues.

Background and Objectives Two main mechanisms for salt tolerance in plants are low rate of salt transport to shoots and tolerance of high leaf salt concentrations by sequestration of Na within cells vacuoles. Recently research for genetic variation in Na + accumulation within bread wheat has revealed large variation in leaf Na + accumulation in leaf is an important physiological process conferring salt tolerance to wheat. Many studies have shown that low sodium concentration in leaves correlate with salt tolerance. Sodium concentration in leaves may be influenced by sodium uptake by roots and transport from root to shoot. Materials and Methods + concentration. The control of Na + In order to understand the salt tolerance mechanisms and the pattern of Na accumulation, 3 bread wheat cultivars differing in salt tolerance (Kavir, Mahdavi and Jajan), were evaluated through two factorial experiments based on completely randomized design in three replications. Experiment 1 used 3 cultivars (Kavir, Mahdavi and Jajan) with four salt treatments (0, 50, 100 and 150 mM NaCl) and experiment 2 used three cultivars (Kavir, Mahdavi and Jajan) with two salt treatments (0 and 150 mM NaCl). Results + + Leaf Na concentration of genotypes was increased in response to increasing salinity after 14 days but Na + concentration was greater in sensitive genotype (Tajan) than tolerant genotypes (Kavir and Mahdavi). There were no significant differences between genotypes in RGR and shoot: root ratio. Results showed that the differences between genotypes in Na transport were responsible for differences in shoot Na + concentration in the root of all genotypes was the same but salt tolerant genotypes maintained higher K + concentrations. Na + ratio in shoot. Shoot biomass was significantly reduced at 150 mM NaCl, whereas this reduction was almost the same for all genotypes. Kavir had the highest ability to tolerate high leaf tissue concentrations of Na + +: Na + + and leaf Na concentrations were much lower in Mahdavi than two other cultivars. Discussion It seems that the major effect of salinity on shoot biomass was due to the osmotic effect of salt, not due to Na + transport rates from roots to shoots may cause different patterns of sodium accumulation through time. The comparison of genotypes suggests that at least there are two main mechanisms for salt tolerance in hexaploid wheat. One is a lower rate of Na-specific effects within the plant. Differences in Na + accumulation in shoot and the other is tolerance of tissue to high concentrations of Na +.

Background and Objectives Preharvest and harvest conditions can affect quality and biochemical composition of fruit during storage. Pomegranate (Punica granatum L. ) is a non-climactric fruit and there is no clear physiological index to determine the proper harvest time. Lack of standard maturity index results in prolonged period of picking pomegranate fruit within the season. The effects of different physical or chemical treatments on postharvest quality of pomegranate fruit have been investigated in many studies, but our knowledge on the pre-harvest and harvest aspects that influence pomegranate fruit postharvest physiology is scarce. The objective of the present experiment was to determine how qualitative indices of pomegranate fruit in ‘ Bagmalek’ (Khuzestan, southwest of Iran) are affected by maturity stages at harvest and storage duration. Materials and Methods A factorial design including three harvesting times and three storage durations with three replications was used for statistical analysis. Fruits of ‘ Malas Post Zard’ as an important pomegranate cultivar were harvested from a commercial orchard in ‘ Bagmalek’ (150 Km Ahwaz, Khuzestan, southwest of Iran). Fruits were harvested at three harvest times at 14-day intervals (14 September, 29 September and 13 October 2011) and stored for 40 and 80 days at +7 C. Some physical (weight, surface color, decay and shriveling) and biochemical characteristics (ascorbic acid, total soluble solids, titratable acidity, pH, anthocyanin index and browning index) were evaluated. The factors were evaluated at harvest time and after 40 and 80 days. o Results Regardless of storage durations, pomegranate fruit showed significant variations in total soluble solids, titratable acidity, pH and anthocyanins. Interactions of the harvest time and storage duration (for 40 and 80 days) were significant on gravity, surface color changes, shriveling, ascorbic, acid, pH, titratable acidity and fruit juice pigments (anthocyanin index and browning index). Results showed that the period 29 September until 13 October 2011 and storage duration for 40 days are the best treatments to maintaining postharvest quality of ‘ Malas Post Zard’ fruits in ‘ Bagmalek’ (Khuzestan, Iran). Discussion Results showed that quantity and quality indices of the pomegranate could be improved through the selection of proper harvesting time. Harvest of pomegranate fruit at different maturity stages altered fruit appearance quality indices and biochemical characteristics under ‘ Bagmalek’ geographic condition, and at early harvest time (14 September), it reduced fruit quality but did not make its consumption unacceptable. More research needs to assess the effect of different climatic parameters such as temperature and light intensity on the postharvest quality of pomegranate fruits in Khuzestan.

Background and Objectives The impact of toxicity of heavy metals such as cadmium in living organisms is a major global concern. Plant kingdom also is not exempted from the adverse effects to exposure of heavy metals. This study was conducted in order to investigate the effect of different priming on seed germination indices of sorghum under Cadmium chloride and nitrate stress condition in laboratory. Materials and Methods The germination experiment was carried out as factorial based on a completely randomized design with four replications. The first factor was heavy metal treatments including 7 levels of cadmium chloride and nitrate, each in four levels (0, 200, 400 and 600 mM) and the second factor included 9 levels: gibberellic acid priming at concentrations of 400 and 800 mg/l, salicylic acid in two levels 0. 3 and 0. 6 mM, potassium nitrate with concentrations of 1 and 2% and concentrations of-3 and-6 bar of PEG and non-priming. Results The results of the germination experiment showed that the highest and lowest seed germination rates and percentage were obtained in 200 mM of cadmium nitrate and 600 mM of cadmium nitrate and chloride treatment, respectively, while 0. 3 and 0. 6 mM of salicylic acid application increased the germination rate. The highest and lowest length and weight vigor index were observed in 0 mM cadmium and 600 mM of cadmium chloride respectively, that 800 mg/l of gibberellic acid application leads to increasing the vigor index. Catalase activity in seed sorghum was increased by increasing of cadmium concentrations but decreased by using different priming. Discussion In relation to the slow germination under stress cadmium cell membrane, probably one of the important points is that the severely damaged cells leak out and vigor will be reduced. Priming with the reconstruction of damaged cells, reduces barriers to the growth of the fetus, increases the quality and quantity of protein synthesis, and increases tolerance to environmental stresses. Cadmium also reacts to sulfhydryl groups in the structure of enzymes and proteins. Plant water relations and gas exchange pores have a negative effect on processes of respiration and photosynthesis and increase production of reactive oxygen species in plant cells causes. Active oxygen species due to the desire for high electron affinity, and the basic biomolecules such as lipids, cells, proteins and nucleic acids can cause damage.

Background and Objectives Table grape (Vitis vinifera L. ) is one of the most important horticulture crops in Iran. In some regions, due to excess water and good climate, the vegetative growth is more than normal. The canopy plays a key role in light energy capture via photosynthesis apparatus, water use as regulated by transpiration, and microclimate of ripening grapes. Canopy management is an important aspect of viticulture due to its effect on grape yields, quality, vigor, and the prevention of grape diseases. Where vineyards have access to a permanent and unlimited water source, irrigation can be managed so that water stress is imposed during certain periods of time to increase fruit quality and to control canopy. This study was conducted to investigate the effects of different levels of topping times and preharvest cut-off irrigation treatments on the qualitative and Quanitative characteristics of Askari grapes in Dena (Sisakht) region during 2013-2015. Materials and Methods ‘ Askari’ vines were 18 years old on their own roots, trained as a head system. The vines were spaced 2. 5 × 3 m. They were pruned as spur pruning which left 60 buds (4-node spurs) on each vine. Vineyard had a drip irrigation system. Shoot topping done at 10th buds of the last cluster. An experiment was arranged as factorial that the first factor included different levels of topping dates with four levels (control, after fruit set, unripe stage and veraison stage), and the second factor involved the preharvest irrigation cut-off date treatments on four levels (Control, 70, 80 and 90 days after full bloom) in a randomized complete blocks design with four replications. Factors relating to the determination of the quality of fruit juices included %TSS, pH, TA%, vitamin C and TSS/TA ratio respectively. Also, bunch weight and yield were measured. Results Results of the analysis of variance showed that the effect of topping and irrigation cut-off date treatment were significant on the TSS, TSS/TA, pH and Vit-C content (P≤ 0. 01). But the interaction effects were significant only on the TSS/TA and Vit-C (P≤ 0. 01). Finally, mean comparison showed that the highest vitamin C was observed at veraison stage and irrigation cutoff dates treatments at 80 and 90 days after full bloom. Discussion In some of vineyards, high vigour vines also have too much canopy shading which is detrimental to the light microclimate and has also been shown to lead to increase of TA and decrease of TSS and TSS/TA ratio. Therefore, canopy manipulation is used successfully in grape production to balance the vegetative and reproductive growth of vines. Differences in vine water status before veraison has been shown to have no effect on the onset of veraison, while withholding water after veraison can delay the accumulation of soluble solids under severe water deficits. Certainly, light and temperature are the most important environmental conditions that impact the growth and quality of grapes and unshaded conditions affect better coloring and increase TSS/TA ratio.

Background and Objectives The use of transplanting is a safe method for adequate crop establishment. Its benefits include increasing yield, reducing the growing season, improving weed control, increasing water use efficiency, improving seedling establishment and increasing crop growth rate. Transplanting increases crop yield compared with direct seeding, this compensates for more cost of transplanting. Transplanting also increases maize yield compared with direct seeding through increasing radiation use efficiency and harvest index. The experiment was aimed to assess direct seeding and transplanting system under the usual time and early planting date for achieving maximum maize seed yield and dry matter. Materials and Methods The experiment was conducted at Research Greenhouse and Field, Campus of Agriculture and Natural Resources, Razi University during two years (2015 and 2016). In the first year, factors included three planting methods (seeding, 4-week transplanting and 6-week transplanting) and two sowing dates (early sowing, common date sowing). In the second year, treatments included 6-week transplanting at early sowing (superior treatment in the first year) and seeding (control). Studied traits included plant height, leaf number, fresh weight, dry weight, stomatal conductance, SPAD, chlorophyll, leaf area, leaf relative water content and yield traits such as ear weight, ear length and diameter, seed number per ear row, row number per ear, 100-seed weight and seed yield. Data were analyzed by SAS software. Means were compared using LSD test. Results The first year results showed that early sowing increased plant height, SPAD index and specific leaf weight compared to usual sowing date. 6-week transplanting at early sowing had the highest dry matter production and leaf to stem ratio. The second year results showed that transplanting increased the leaf number, chlorophyll content, fresh and dry weight, leaf area, ear length, ear diameter, seed number per ear row, row number per ear, ear weight, seed yield, 100-seed weight and tassel weight compared to direct seeding. Discussion Yield increase in transplanting was probably due to high leaf area and plant height that plants greatly used environmental conditions such as light and water. So seed number per ear row, row number per ear and ear length were high. In conclusion, 6-week transplanting at early sowing (29 March) is suggested to achieve the highest seed yield in Kermanshah. Maize transplant ages except the ages studied in the experiment are recommended for the next experiments.

Background and Objectives Identification and collection of superior genotypes in horticultural plants is the first step in breeding programs. In our country, insufficient knowledge about horticultural plants germplasm is the important limiting factor for improving programs on horticultural crops specially cucumber. The aim of this study was grouping of different cucumber genotypes based on some morphological traits and their genetic distances. Materials and Methods 25 cucumber lines were evaluated by measurement of 25 morphological traits using principal component and cluster analysis. Seed of all lines were obtained from the Asian Vegetable Research and Development Center (Shanhua, Tainwan). To develop transplants cucumber seeds were sown in single plastic pots (12×11 cm) filled with peat in a greenhouse. The loamy sand soil was prepared by plowing and disking. There was a preplanting application of urea nitrogen, 50 kg· ha-1, and 100 kg· ha-1 of phosphorus. The soil was formed into raised beds with rows on 1. 2 m centers. Data were collected from 12 plants in a row per plot of each accession and 25 morphological traits were determined. Results The result of PCA showed that twenty main factors accounted for %88 of total variance. Contribution of each component to arrangement was 17. 97, 12. 25, 11. 45, 8. 74, 7. 52, 6. 12, 5. 13, 4. 53, 4. 29, 3. 77, 3. 44, and 2. 86 percent of total variance. Cluster analysis based on Euclidean distance and UPGMA was used to cluster the lines. According to the cluster analysis the lines were grouped in 7 clusters and cophenetic coefficient was 0. 842. Discussion In this research, there was high genetic diversity between the studied lines that can be used for heterosis breeding by parental line selection for crossing to reach suitable cultivars.

Background and Objectives Wheat (Triticum aestivum L. ) is one of the world's major cereal crops. Approximately, one sixth of the total arable land is cultivated with wheat. Plant density is an important management factor on crop yield. A major component in a crop growth model is leaf area development which has a major influence on photosynthesis and transpiration. Leaves senesce because of the natural biological process of ageing, but the effect of water deficit can markedly reduce leaf longevity. The aim of this research was to model the effect of plant density on the production and aging leaves of two wheat cultivars (Gascojen and Pishtaz) under irrigation cut off conditions at the end of growth period. Materials and Methods In order to model of leaf production and senescence in wheat, the experiment was conducted as a factorial based on randomized complete block design with four replications. The experiment was carried out at research farm of Saleh abad, Torbatjam, Iran in 2011. Treatments of this experiment were plant densities (50, 100, 200, 300, 400 and 500 plant in m ) and cultivars (Gaskojen and Pishtaz). In this experiment, irrigation was removed in stem elongation and seed development stages. 2 Results Phyllochron in wheat approximately was 102 GDD and showed ending after receiving 900 GDD. Plant density had no effect on leaf appearance and phyllochron. Leaf senescence in the main stem started when the main stem had about 5 leaves and proceeded at a rate of 0. 7 per unit increase in GDD. Leaf production per plant versus main stem leaf number occurred in two phases; phase 1. Production increased when plant leaf number occurred with a slower and density-independent rate: phase 2. Production increased with a higher and density-dependent rate of leaf. A close relationship was found between the fraction of senesced leaves per plant and the same fraction on the main stem. Leaf lifetime average decreased with increasing density. Gaskojen was paramount to pishtaz variety in number and lifetime of leaf. Discussion The results showed that leaf production and senescence of wheat in different plant densities on terminal stage water holding conditions could be quantified using different equations.