جستجوی مقالات مرتبط با کلیدواژه "اسپرمین" در نشریات گروه "باغبانی"

Plants are exposed to various environmental stresses during their growth period in nature and under field conditions. Due to its medicinal and therapeutic properties, Silybum marianum L. Gaertn. has been used since ancient times for the treatment of liver and gallbladder diseases. This study aimed to investigate the response of Silybum marianum to plant growth regulators under different soil moisture conditions.

The present study was conducted in the agricultural year 1401-1400 at the Forests and Rangelands Research Institute research farm located in Karaj, Iran. The research farm is 5 kilometers southeast of Karaj city at a geographical latitude of 35 degrees and 48 minutes north and a longitude of 51 minutes east, with an elevation of 1320 meters above sea level. The study was carried out in a randomized complete block design with three replications. The experimental treatments included different levels of field capacity (90%, 75%, 50%, 25% FC) and foliar application with plant growth regulators such as salicylic acid (75-150 mg.l-1), spermine (70-140 mg.l-1), brassinosteroid (C28) (1-1.2 µM), and water (control). Soil moisture levels were determined daily using the weighing method and TDR (Time Domain Reflectometry) in the range between field capacity and 25% soil moisture content. Irrigation was conducted according to the desired treatments throughout the growth period based on the plotted graph and with the help of TDR. Foliar spraying was performed seven days apart in three stages, five months after seed sowing in April. At the end of the study, traits including average leaf number, leaf area, canopy diameter, number of lateral branches, root length, root collar diameter, days to leaf emergence, fruit antioxidant capacity, fruit color index, seed ash percentage, leaf sugar content, thousand seed weight, fruit yield, and oil content were measured.

 The study showed that the reduction of field capacity (FC) reduced growth and yield traits in the plant compared to the control treatment. However, the foliar application of plant growth regulators improved growth traits effectively. For instance, the leaf number in the 25% field capacity treatment was almost halved compared to the control treatment (90% field capacity). Foliar spraying with brassinosteroids prevented a significant decrease in leaf number in the plant under different field capacity levels. The highest leaf area was observed in the treatment with 140 mg.l-1spermine + 75% field capacity. Foliar spraying with spermine and brassinosteroids had a significant effect on improving growth traits under stress conditions. Foliar spraying with spermine or brassinosteroids resulted in the highest oil content in the fruit under 50% field capacity conditions. Under 75% field capacity, foliar spraying with brassinosteroids (1 µM) increased fruit yield in the plant by 71% compared to the control treatment at the same stress level and by 5.5% compared to the control treatment under 90% field capacity conditions. The correlation analysis between color indices and fruit antioxidant capacity showed a positive and significant correlation between the percentage of fruit antioxidant capacity and brightness index (L), indicating that fruits with darker colors had higher antioxidant capacity. However, the redness index (a) and yellowness index (b) had a negative and significant correlation with fruit antioxidant capacity.

The research findings have shown that reducing field capacity reduces plants' vegetative and reproductive growth parameters. However, foliar spraying plants with plant growth regulators improves plant growth conditions under water-limited conditions. In general, based on the research results, foliar spraying of plants with spermine at a concentration of 140 mg.l-1 helps improve the growth and performance characteristics, increasing the plant's resistance to moisture stress conditions in the soil.

Nitrogen plays an important role in the uniformity and quality of citrus trees. Several studies previously reported that a low level of nitrogen in citrus trees is generally caused a reduction in yield and fruit quality (Aziz, 1997; Khan et al., 2009). In this regard, applying urea is recommended as the most suitable form of nitrogen for foliar application. The polyamines are included; putrescine, spermidine, and spermine which have been considered as plant growth regulators (Alcazar et al., 2010; Khezri et al., 2010). The role of nitrogen in vegetative and reproductive growth and yield, as well as the correlation between polyamines, flower induction and fruit set in other plants, were proved in previous studies. In this regard, the results of the current study will increase our understanding about the role of polyamines in the morphology of the tree and also the mechanism of regulating the alternate bearing of Kinnow mandarin leading to an approach method to address this problem.

To conduct this study a 17-year-old uniform of Kinnow Mandarin (Citrus reticulate Blanco) grafted onto Bitter orange (Citrus aurantium) rootstock, which grown in a commercial orchard, located in Dezful (Khuzestan Province in Iran). For sampling, the branches which possess leaves and nodes were selected from four sides of each tree, then leaves and nodes were collected at three different time points (one, three, and five weeks post-treatment). Samples were immediately frozen in liquid nitrogen after excision and transported to the Physiology Laboratory of fruit trees within 2h for determining the N fractions and polyamines. The concentration of N in dried leaves and nodes was determined using the colorimetry technique as described by Walling et al. (1989). The experiment was set up as a factorial treatment based on a randomized complete block design with three replications to investigate the effect of different concentrations of urea foliar application (0, 0.75%, 1.5%) on nitrogen and polyamines contents at different time points (Dec 22, Jan 5, Jan 20) followed by evaluating flower characteristics and yield in Kinnow mandarin plant. Data analysis including variance was carried out using MSTATC and SAS software. To compare the mean of polyamines and nitrogen in leaves and nodes, the cut-out method was used, and also for comparison of pistil dimensions, number of flowers, and yields, Duncan's multiple range test (DMRT) was performed.   

Results indicated that polyamines concentration and nitrogen decreased during the period of time and also, in most cases, polyamines concentration was lower in the nodes than the leaves. High levels of polyamines and nitrogen were obtained in leaves and nodes which were treated with the foliar application of 1.5 % urea concentration after Jan 20. The polyamines content in leaves and nodes was greatly dependent on the spraying time and urea concentration used. Spermine (Spm) was the dominant polyamines in leaves and nodes with the highest values of 44.01 nmol/gF.W, 34.41 nmol/gF.W, respectively. Regarding the fact that flower density was higher in trees that treated with urea concentration of 1.5 % after Jan 5 y than other treatments, however, their yield was lower than the trees that treated on Dec 22 with the same urea concentration. This was probably due to the flower abscission as well as the fruit abscission in June. The results of this study showed that the highest yield was obtained with 1.5 % urea concentration after foliar application on Dec 22 compared with other treatments. Regarding the fact that flower differentiation in mandarin occurs during the late January until late February (in Dezful conditions), it can be explained that the foliar application on Dec 22 was performed before differentiation and consequently, the trees have received their required nitrogen. Also, the low-temperature is considered as natural inducer of citrus flowering in the Dezful, likewise, foliar fertilizer application in winter along with the natural factor (low temperature) stimulates flowering in a larger number of buds resulting in increasing the flowering. As nitrogen promotes vegetative and reproductive growth, it can be said that increasing the nitrogen content of leaves followed by transfering to the nodes, increases the number of buds, especially reproductive buds, which leads to an increase in flowering and yield. According to this study, the foliar application of urea in winter with 1.5% concentration can increase yield in Kinnow mandarin trees. Therefore, polyamines can play an important physiological role in flower development of Kinnow mandarin.

In this study, we focused on the effect of the foliar application urea during winter on leaves and nodes of Kinnow mandarin trees and investigated the polyamines, Put, Spm, and Spd contents upon treatments. In conclusion, the application of foliar urea in winter resulted in the significant endogenous increase of polyamines and N in the leaves and nodes of Kinnow mandarin trees. Also, yield, flower density, and pistil diameter were increased by spraying urea. There is a possibility that free polyamines affect on physiological processes.

Polyamines are low molecular weight organic polycations containing two or more amino groups and their application in agriculture is going to increase as a result of their positive impact on plant physiological responses. This greenhouse study was applied in a factorial experiment based on completely randomized design to evaluate the effects of polyamines (putrescine and spermine) at four levels (0, 0.5, 1 and 2 mM) on morphophysiological characteristics of Dutch iris (Iris hollandica 'Blue Magic'). Foliar spraying treatments were performed from 3-leaf stage, weekly. The results showed that putrescine and spermine increased vase life and flower diameter and the highest record was observed in 2 mM putrescine treatment. Plants that treated with 2 mM putrescine and spermine had the greatest amount of petals anthocyanin and leaf chlorophyll content. All polyamines treatments increased post-harvest flower fresh weight and petals soluble solids content and the maximum rise was detected by 2 mM putrescine application. According to the results of this study, the best results were found in both 2 mM putrescine and 1 mM spermine treatments, where the lowest electrolyte leakage and malondialdehyde content and the most antioxidant enzymes catalase and ascorbate peroxidase activities was obtained.

Pistachio (Pistacia vera L.) is an important horticultural crop that has high economic value. Pistachio trees display some physiological disorders including abscission of inflorescence buds, fruit abscission, blankness, non-splitting, early splitting and deformation of nuts. Unfavorable environmental conditions in most pistachio orchards and inadequate nutrition during the flowering time and after flowering has increased these problems in recent years. Polyamines such as putrescine, spermine and spermidine are some low molecular weight polycationic compounds that have been shown to play an important role as growth regulators in different stages of growth and development of buds, flowers and fruits and resistant plants to abiotic and biotic stress. Therefore, the objective of this study was to investigate the influence of polyamines in water scarcity condition on growth, nut traits and yield of ‘Akbari’ pistachio trees. The study was carried out in growing season 2016 in a pistachio orchard (Pistacia vera L. cv Akbari) located in Feyzabad, Mahvelat, Khorasan Province, Iran (34° 40´ N latitude, 58° 25´ E longitude, and around 1253 m above sea level). The climate of the experimental area was arid and semi-arid. The mean annual precipitation was about 171 mm. The irrigation of orchard trees was at 36-day intervals. The experiment was conducted as split plot based on a randomized complete block design with three replications and seven treatments including polyamines spray of Putrescine (Put), Spermine (Spm) and Spermidine (Spd) at concentrations of zero (control), 0.1 and 1 mM on “on” and “off” pistachio trees cultivar Akbari at two-time stages full bloom (FB) and two weeks after full bloom (2WAFB). Leaf chlorophyll index was recorded using the chlorophyll meter (SPAD-502, Konica Minolta, Japan). Leaf area from fully expanded leaves was measured by Digital Leaf Area Meter (LI-3100c). The length and diameter of current-year shoots were measured at harvest time. The percentage of flower bud abscission and fruit abscission were calculated on marked shoots. The yield was calculated by weighting the total dried split nuts separated from each shoot. The data were subjected to analysis of variances (ANOVA) using the SAS software (SAS version 9.1). Difference between means was compared using the least significant difference test (LSD) at 5% level (p ≤ 0.05). Results showed that among the treatments, Put (0.1 and 1 mM) and Spm (0.1 mM) applied in the “on” trees significantly increased leaf chlorophyll index. Also, Put spray at two weeks after full bloom indicated better results in increase of length shoot in ‘on’ trees. All of the polyamines reduced fruit abscission in the “on” trees however, Put at 0.1 and 1 mM concentrations with 11.3 and 11.1% was more effective in decreasing the percentage of fruit abscission compared to other treatments. Fruit abscission of pistachio is assumed to be related to improper fertilization, the dominance of fruits in a cluster or abnormalities of reproductive organs. Polyamines have been suggested to improve fertilization, and subsequent embryo and fruit development. It also has been reported that common precursor of S-adenosylmethionine (SAM) needed for synthesizing both of PAs and ethylene. Thus, it seems that polyamines reduce the abscission of fruits by the improvement of embryo growth and development or by antagonism with ethylene, possibly by competing for S-adenosylmethionine (SAM). Our study indicated that all of the polyamines decreased the percentage of blank nuts in the “off” trees especially two weeks after full bloom. The results showed that Put (0.1 and 1 mM) and Spd (0.1 mM) were very effective in increasing number of nuts per cluster.  Number of nuts per 100 g, split nuts, and kernel percentage did not differ significantly among treatments. Yield variations were not significantly affected by polyamines in in the “off” trees, but in ‘on’ trees, polyamines of Put, Spm and Spd at 0.1 mM concentration by 46.2, 14.6 and 15.2% and at 1 mM concentration by 38.7, 24.7 and 19.9% increased yield compared to control, respectively. Given to correlation results, the positive effect of polyamines on yield improvement in ‘on’ trees was mainly due to the prevention from fruit abscission and enhancement no. of nuts per cluster. Results showed that application of polyamines treatments in ‘off’ trees only on blank nuts and in ‘on’ trees on leaf chlorophyll index, fruit abscission, No. of nuts per cluster and yield was effected. Foliar application of polyamines was more effective in improving traits of shoot length, leaf area and blank nuts two weeks after full bloom compared to full bloom. The results of this study showed that these plant growth regulators, especially putrescine, had the potential to improve growth, yield and reduce physiological problems of pistachio under unfavorable environmental conditions.

In order to study the effect of water deficit and foliar application of salicylic acid and spermine on the phenological stages and caffeic acid derivatives yield of Echinacea purpurea L., a three replicated split- plot experiment was conducted based on a randomized complete block design during 2016 and 2017 growing seasons at the research field of Research Institute of Forests and Rangelands, Iran. In this experiment, three irrigation regimes (irrigation after 20, 40 and 60% depletion of soil available water) were accommodated in main plots and salicylic acid (SA) and spermine (SPM) spray treatments (Control (no spray), spray at five levels of 75 mg/l SA, 150 mg/l SA, 75 mg/l SPM, 75 mg/l SA+75 mg/l SPM and 150 mg/l SA+75 mg/l SPM) were considered in subplots. The exogenous SA and SPM were applied on the foliage at two steps, 10-days apart and at the beginning of stem elongation stage. The effects of irrigation regime and spray treatments were significant on the traits studied. Drought stress decreased the number of days to phenological stages, the yield of echinacoside and cynarin in flower and cichoric acid, and caftaric acid and cynarin in leaves, but increased the yield of chlorogenic acid in flowers and caffeic acid derivatives (cichoric acid, echinacoside, chlorogenic acid, caftaric acid and cynarin) in roots. The foliar application of salicylic acid and spermine increased all studied traits. The interaction between water deficit and foliar spray was significant on the yield of caffeic acid derivatives in roots. The highest yield of cichoric acid (9.49 kg/ha), echinacoside (0.67 kg/ha), chlorogenic acid (0.26 kg/ha), caftaric acid (7.31 kg/ha) and cynarin (0.27 kg/ha) in roots was obtained at irrigation after 60% depletion of soil available water and simultaneous application of high concentrations of SA and SPM. Based on the results of the present study, the foliar application of SA and SPM improved the yield of caffeic acid derivatives in coneflower under both normal and water stress conditions.

Keeping fresh pistachio appearance after harvest had important role in economic value of this produce. In this research, pistachio trees were sprayed with 1 mM of putrescine, spermidine and permine 20 days before harvest. Foliar spraying by distilled water was considered as control. Harvested fruits were coated by chitosan (0 and 1%) and stored at 2±1 oC and 90±5% R.H. The fruits were evaluated at 0, 20, and 40 days of storage. The results showed that hull and kernel firmness, hull and fruit water content, L* index in hull and shell, hue angle and chroma indices, chlorophyll content were decreased during storage but application of polyamines maintained these traits in comparison with control. The results also indicated that combined application of putrescine and chitosan improved these characteristic than alone application of each.

Improvement of growth and flowering with polyamines application has been reported in different plants. So, in this study application of exogenous polyamines on quantitative characteristics, vase life and endogenous hormones and polyamines contents in rose flower was investigated. For this purpose, an experiment was conducted as randomized complete block design (RCBD) with ten treatments, three replications and two observations in each replication in a hydroponic greenhouse in Yasouj city. Treatments were including foliar application of putricine (Put) at 1, 2 and 3 mM, spermidine (Spd) at 0.5, 1 and 1.5 mM, spermin (Spm) at 1, 2 and 4 mm and control. The highest and the lowest fresh weight and flower height were obtained in the plants treated with Spd 1.5 mM and control, respectively. Foliar application of polyamines increased the vase life, so that maximum vase life (16 days) was observed in treated flowers with Spm 1 mM as compared to the other treatments. The highest content of IAA, GA3 and zeatin obtained in treated flowers with Spm 4 mM. The highest ABA content was found in treated flowers with Spd 1.5 mM. The use of exogenous polyamine increased the internal Put and Spd contents. So, the final results of this study revealed that exogenous application of 1.5 mM Spd and 4 mM Spm due to increasing of internal hormones and PAS, caused to increase of vegetative properties and vase life of rose cv. Dolcvita.

Pistachio is one of most important horticultural crops in Iran, USA, Turkey and some Mediterranean countries. Some physiological problems such as abscission of inflorescence buds, blankness, non-splitting, early splitting, cracking and nut deformation reduce the pistachio yield and quality.
This experiment were carried out in a commercial 20-year old ‘Ahmad-Aghaii’ pistachio orchard in Rafsanjan, Iran. It was arranged as factorial based on randomized completely block design with three replications.
Results showed that the main physiological problems of pistachio crop were decreased by application of calcium compounds combined with free polyamines. Spray application of the mentioned treatments was more effective at combined stages of 1 and 2 rather than the stages separately. It was resulted that calcium nitrate combined with spermine and spermidine treatments at combined stages of 1 and 2 reduced the abscission of inflorescence buds, blankness, nut deformation and non-splitting. Also, it was found that calcium nitrate combined with spermidine at combined stages of 1 and 2 reduced the percentage of early splitting while splitting and yield were increased.

This experiment was carried out to investigate the effect of polyamines on growth, flowering and corm production of ‘Golden Wave’ and ‘Blue Sea’ cultivars of freesia. For this purpose, freesia plants were sprayed at 35, 70 and 100 days after planting with concentrations of 0.5 and 1 mM of putrescine, spermidine and spermine and distilled water (control). The factorial experiment was performed in a completely randomized design with 3 replications and 2 pots for each replicate. Results showed that spermine treatment delayed flowering time. But spermidine treatment accelerated flowering and also increased leaf length, flowering stem height, inflorescence height, diameter and length of florets and number of lateral stems in both cultivars. Maximum number of corms was obtained in spermidine treatment. But, plants treated with putrescine had more corm weight and diameter than other treatments and control. Polyamines increased leaves nutrient concentration. The highest nitrogen concentration (2.39 and 2.37 percent) was observed in putrescine and spermine treatments and the highest concentration of phosphorus (0.47 and 0.46 percent), potassium (3.1 and 3.03 percent) and zinc (51.31 and 50.3 mg/L) was obtained in spermidine and putrescine treatments. Almost all polyamines increased magnesium concentration of leaves. The results of this study revealed that polyamines, and especially spermidine and putrescine, could increase yield and improved quality of flower and corm of freesia.