Pomology
Esmaeil Khaleghi; Masumeh Zamani Dehbari; Norollah Moallemi
Abstract
IntroductionCitrus fruits are one of the most commercial fruit products in the world, whose growth and production are affected by abiotic stresses. Drought stress is one of the most important abiotic stresses that affects all the vital processes of the plant. One of the ways to moderate the negative ...
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IntroductionCitrus fruits are one of the most commercial fruit products in the world, whose growth and production are affected by abiotic stresses. Drought stress is one of the most important abiotic stresses that affects all the vital processes of the plant. One of the ways to moderate the negative effects of drought stress is the use of polyamines. Polyamines are a group of biochemical compounds that are used as one of the most effective compounds to resist environmental stresses. Polyamines have a wide role in various plant growth processes, such that they play a significant role in modulating various types of biotic and abiotic stresses. Studies have shown that application of putrescine increases the fresh and dry weight of the shoot and root parts, leaf relative water content, photosynthetic pigments, leaf surface, and photosynthesis in plants under drought stress. Materials and MethodsThis study was conducted to investigate the effect of different levels of putrescine (0, 0.5, 1 and 2 mM) and different levels of irrigation (100, 75 and 50% of evotranspiration potential) on morpho-physical traits of lime seedlings as a factorial experiment based on randomized complete block design with 3 replications.Two-year-old lime seedlings were obtained from a commercial nursery located in Dezful city (approved by the Khuzestan Agricultural Jihad Organization). Then, they were located in 15-kilogram pots and kept for 2 months in the greenhouse to adapting to the environmental conditions. In order to apply the irrigation regime, 4 pots were considered as reference plants and the amount of irrigation water was determined by weighing these pots. First, the weight of reference pots was calculated in field capacity mode. Then, after 7 days, the pots were weighed again and the difference between the primary and secondary weights was considered as the amount of irrigation water of 100% plant evaporation and transpiration, and according to that, 75% irrigation and 50% evaporation and transpiration potential were applied. The first foliar spraying with putrescine was done at first of March in Field capacity (foliar spraying was done once every month for 4 months from March to June). At the end of the experiment, the fresh and dry weight of root and shoot, number of leaves, relative water content, leaf water potential, photosynthesis, transpiration, stomatal conductance, were measured. Statistical data analysis was done using MSTATC software and, Duncan's multi-range test was used to mean comparation at the 5% probability level. Results and DiscussionResults showed that the rate of photosynthesis, stomatal conductance, relative water content of leaves, fresh and dry weight of aerial part and root decreased by reducing the amount of irrigation from 100 to 75 and 50%, of ETcrop. The reduction of growth parameters under drought stress can be due to the closing of the stomata and the reduction of carbon dioxide emission into the leaves, which can lead to lower levels of chlorophyll and photosynthesis, induction of oxidative stress, and finally less growth in plants. It has also been stated that the decrease in growth caused by drought stress in the initial stages of the stress can be due to the decrease in cell growth and development due to the decrease in turgor pressure and the decrease in the intensity of photosynthesis due to the closing of stomata. Also, the results showed that foliar spraying with 2 mM putrescine increased photosynthesis, stomatal conductance, relative water content of leaves, wet and dry weight of aerial parts and roots at all irrigation levels. The researchers believed that the increase in growth parameters, relative water content and photosynthetic pigments with putrescine foliar spraying can be related to the antioxidant properties of putrescine and its osmolality role in dry conditions. Other researches have shown that putrescine may modulate certain ion channels and increase the permeability of the membrane to calcium and cause a decrease in the entry of potassium into the membrane, which causes a decrease in the exit of water from the cell. Also, putrescine may increase leaf water potential and leaf content through osmotic regulation of the plant by increasing proline. ConclusionIn general, the results showed that foliar spraying of putrescine, especially at 2 mM concentration has the greatest effect on increasing growth parameters, including fresh and dry weight of shoots and roots, leaf area, increasing the relative water content, leaf water potential and Gas exchanges and reducing the amount of ion leakage under drought stress conditions.
Zeinab Safaei; Majid Azizi; Hossein Arouiee; Gholamhossein Davarynejad
Abstract
Introduction: Nigella sativa L. is one of the herbs that has a variety of uses and has been used in Iran’s traditional medicine since old times. Today this plant is considered as one of the most important kinds of medicine. Almost all the metabolic activities of plant cells, including the construction ...
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Introduction: Nigella sativa L. is one of the herbs that has a variety of uses and has been used in Iran’s traditional medicine since old times. Today this plant is considered as one of the most important kinds of medicine. Almost all the metabolic activities of plant cells, including the construction of active ingredients in medicinal plants, depend on lack of absorbable water by plants can lead to the morphological, physiological and biochemical changes, including decrease of cell swelling and growth and thus reduction of leaf area and plant height, stomatal closure and photosynthesis restriction, increase of soluble compounds for regulating the osmotic pressure, reduction of nutrient absorption and ultimately reduction of crop production. The use of anti-transpiration compounds is considered as a promising tool for the regulation of transpiration in respect of water conservation at an optimal level, where the strategies such as the use of anti-transpiration compounds have the potential for transpiration regulation. The aim of the present study is to improve the yield and yield components of medicinal plant N. sativa by anti-transpiration compounds under drought stress conditions.
Materials and Methods: The research was done using a split plot experiment on a randomized complete block design with three replications. The irrigation intervals (8 and 16 days) in main plots and anti-transpiration compounds of chitosan (0.25, 0.5 and 1 %), Plantago psyllium mucilage (0.5, 1 and 1.5 %) and arabic gum (0.25, 0.5 and 0.75 %) were put in subplots with three replications. Also, the distance between the main plots in each block and distance between the two blocks were assigned as 100 cm and 200 cm, respectively; so that the moisture content of a plot had no effect on the adjacent plots. Planting date was April 16 and planting was performed by hand in 0.5cm-deep furrows. Anti-transpiration compounds were sprayed simultaneously with applying drought stress till the flowering stage once a week at sunset. Plant height, leaf area index, irrigation water efficiency index, leaf temperature and stomatal conductance were measured.
Results and Discussion: The results showed that there were significant differences between treatments in all studied traits. The best rate of the measured traits was observed at 8-day irrigation interval and chitosan treatment. Providing plant favorite conditions such as reducing plant temperature, increasing morphological traits comparing to rainfed at 16-day irrigation interval. Applying arabic gum did not improve growth but acted as a growth inhibitor. Anti-transpiration compounds led to significant changes in all the studied traits compared to the control, indicating the effectiveness of these natural compounds. Chitosan stimulating abscisic acid synthesis in the treated plant would result in stomatal closure, reduction of stomatal conductance, transpiration rate and water content. It also pointed out that the anti-transpiration effect of chitosan was because of its stimulatory effect in increasing abscisic acid concentration in the treated leaves of bean plant. As the above compounds are natural and biodegradable, as well as safer and less expensive than other chemical anti-transpiration compounds, they can serve as a good alternative to the chemical compounds. Cognition and expertise in water relations of plant and drought stress tolerance is considered as the main program in agriculture and the ability to withstand this stress is of great economic importance.
Conclusion: The important processes, including nutrition, photosynthes is, stomatal opening and closure and growth are all influenced by water. In this study, it was observed canopy temperature and stomatal conductance would increase at 16-day irrigation interval, where the increase is considered as a drought tolerance mechanism. Also, the anti-transpiration compounds led to significant changes in terms of all the studied traits compared to the control, indicating the effectiveness of theses natural compounds. Providing the appropriate conditions, 1% chitosan treatment can enhance the yield under drought stress. Spraying by arabic gum did not improve the growth conditions. According to this experiment, 1% chitosan treatment and 1.5% Plantago psyllium mucilage is considered the most appropriate strategy to enhance the yield of Nigella sativa under drought stress.
Mohammad Mahmoodi Sourestani
Abstract
Introduction: Mediterranean climate conditions induce several stresses that plants have to cope with, especially during summer months when high temperature and radiation levels along with low water availability in the soil prevail for long periods. Variation in physiological traits such as photosynthesis ...
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Introduction: Mediterranean climate conditions induce several stresses that plants have to cope with, especially during summer months when high temperature and radiation levels along with low water availability in the soil prevail for long periods. Variation in physiological traits such as photosynthesis and plant water status and their association with morphological characters can play an important role in the adaptability of the species to environmental constraints. The previous studies show that scorching weather not only affects the rate of gas exchange, but also results in diurnal changes in activity. Thus, the impact of environmental stresses on plants growing in these conditions should be assessed by examining the evolution of their diurnal variations on leaf gas exchange. Aromatic plants represent a renewable source of valuable compounds that can be used in food, perfumery, and pharmaceutical industry. Among these plants, sweet basil (Ocimumbasilicum), holy basil (Ocimum sanctum), lemon balm (Melissa officinalisL.) and catnip (Nepetacataria) are very important for different industries. Studies on environmental physiology of medicinal plants are relatively scarce and very few information is available concerning the physiological basis of medicinal plant response to heat stress that is one of the most important factors limiting production of medicinal plants in Khuzestan province.
Material and methods: In order to evaluate the diurnal fluctuation of gas exchange of mentioned plants, an experiment was carried out in 2013 at research farm of Horticultural Science, Shahid Chamran University (31°20'N latitude and 48°40'E longitude and 22.5m mean sea level), Ahvaz (Iran), a site characterized by a semidry and scorching weather during late spring and summer. The experiment was arranged based on randomized complete block design (RCBD) with three replications and 4×8 factorial scheme (Four plants including lemon balm, catnip, holy basil and basil; and eight times of evaluation 7:00,9:00, 10:00, 11:00, 12:00, 13:00, 17:00 and 20:00 h). Land preparation consisted of disking and the formation of raised beds (15cm high and 45cm wide across the top) using a press-pan-type bed shaper. The plants were arranged on two rows on each bed, with 20 cm in-row and 40 cm between-row spacing. The plants were irrigated weekly as needed. Gas exchange parameters were investigated from June 9-11at end of vegetative phase under natural environmental conditions. The parameters of gas exchange were measured on the 5th and 6th nearly full expanded leaves between the hours of 07:00 and 20:00 during bright sunlight on clear and cloudless days. Determination of leaf net photosynthesis rate (Pn), stomatal conductance (gs) and transpiration (E) was made with Infra-red gas analyzer (LCA4, ADC Co. Ltd., Hoddesdon, UK).Instantaneous water use efficiency (WUEinst) and apparent quantum yield(AQY) were calculated as Pn/E andPn/PPFD ratios, respectively.
Result and discussion: The result showed that plant type had significant effect on all measured traits as well as record time. Interaction between plant type and record time were significant for PPFD, leaf temperature and net photosynthesis. The highest Pnof Lemon balm (8.97 µmol CO2 m-2 s-1), catnip (11.2 µmol CO2 m-2 s-1) and sweet basil (13.75 µmol CO2 m-2 s-1) were recorded at 9:00 when the photosynthetic photon flux density (PPFD) was 1488, 1598 and 1645 µmol photon m-2 s-1, respectively. Holy basil showed highest Pn (15.47 µmol CO2 m-2 s-1) at 10:00 when PPFD was 1821 µmol photon m-2 s-1.High irradiances caused photoinhibition of the four plants and it seems the four plants reach to light saturation point about 1500 µmol photon m-2 s-1.The midday depression of photosynthesis likely resulted primarily from long periods of high PPFD, limitation in stomatal conductance and high temperature. Catnip was more sensitive to high irradiance. The Pn had positive and significant correlation with gs in four plants. The stomatal conductance was also positively correlated with E in four plants. The plants represented double peak curve for WUE. The first and second peaks appeared at 9:00 and 17:00, respectively. The four plants also showed highest AQY at 7:00. There were significant difference between four plants for leaf temperature, gs, Pn, WUE and AQY. Lemon balm showed lower leaf temperature than other plants due to its high gs. The highest amounts of Pn, WUE and AQY were observed in holy basil.
Conclusion: In regard to Pn, WUE and AQY, it seems holy basil and sweet basil can tolerate weather condition of Ahvaz.
Zohreh Moghimi pour; Mohammad Mahmoodi Sourestani; Naser Alemzadeh Ansari
Abstract
Introduction: Holy basil is a perennial plant belongs to Lamiaceae family. The plant is a perennial and thrives well in the hot and humid climate. Its aerial parts have been in use for food, pharmaceuticals, cosmetics and perfumery industries. Leaves contain 0.5-1.5% essential oil and main oil components ...
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Introduction: Holy basil is a perennial plant belongs to Lamiaceae family. The plant is a perennial and thrives well in the hot and humid climate. Its aerial parts have been in use for food, pharmaceuticals, cosmetics and perfumery industries. Leaves contain 0.5-1.5% essential oil and main oil components are eugenol, methyl eugenol, carvacrol, methyl chavicol and1,8-cineole. A balanced fertilization program with macro and micronutrients is very important in producing high quality yield. Zinc is involved in IAA production, chlorophyll biosynthesis, carbon assimilation, saccharids accumulation, reactive oxygen radicals scavenging and finally carbon utilization in volatile oil biosynthesis.
Material and methods: In order to evaluate the effect on zinc foliar application on zinc content of leaves, photosynthetic indices and pigments of holy basil, an experiment was carried out in 2013 at a research farm of Horticultural Science, Shahid Chamran University (31°20'N latitude and 48°40'E longitude and 22.5 m mean sea level), Ahvaz (Iran), a region characterized by semi-dry climate. The experiment was arranged based on Randomized Complete Block Design (RCBD) with six treatments and three replications. The treatments were nano zinc chelate (0, 0.5, 1 and 1.5 g.l-1) and zinc sulfate (1 and 1.5 g.l-1) fertilizers. Land preparation includes disking and the formation of raising beds (15cm high and 45cm wide across the top) using a press-pan-type bed shaper. Holy basil seeds were sown on two rows on each bed, with 15 cm in-row and 40 cm between-row spacing. The plants were irrigated weekly as needed. Foliar application of zinc fertilizers was done at six-eight leaf stage and were repeated with interval 15 days until full bloom stage. Zinc content, stomata conductance (gs), CO2 under stomata (Ci), transpiration rate (E), net photosynthesis (Pn), light use efficiency (LUE), water use efficiency (WUE) and also chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoid contents were measured at beginning of flowering stage. Photosynthetic parameters were measured by Infra-red gas analyzer (LCA4, ADC Co. Ltd., Hoddesdon, UK). Instantaneous water use efficiency (WUEinst) was calculated as Pn/E ratio. Light use efficiency was calculated as Pn/PPFD ratio.
Result and discussion: The results showed that the effect of foliar application of zinc fertilizers on all measured traits except Ci and WUE was significant (p≥0.01). The highest values of zinc content (110.53 mg.kg-1), chlorophyll a (0.99 mg.kg-1 fresh weight), chlorophyll b (0.30 mg.kg-1 fresh weight), chlorophyll a+b (1.29 mg.kg-1 fresh weight) and carotenoid (0.18 mg.kg-1 fresh weight) traits were obtained in plants sprayed with 1.5 g.l-1 nano zinc chelate. The lowest amount of zinc content (21.37 mg.kg-1), chlorophyll a (0.58 mg.kg-1 fresh weight), chlorophyll b (0.14 mg.kg-1 fresh weight), chlorophyll a+b (0.72 mg.kg-1 fresh weight) and carotenoid (0.13 mg.kg-1 fresh weight) traits were obtained in control plants. Foliar application of holy basil with 1.5 g.l-1 nano zinc chelate led to increase in stomata conductance (322.22 mm H2O.m-2.s-1), transpiration rate (2.86 mm H2O.m-2.s-1), net photosynthesis (11.75 μm CO2.m-2.s-1) and light use efficiency (6.10 μm CO2. μm photon-1). The minimum amount of stomata conductance (172.00 mm H2O.m-2.s-1), transpiration rate (2.16 mm H2O.m-2.s-1), net photosynthesis (8.23 μm CO2.m-2.s-1) and light use efficiency (4.46 μm CO2. μm photon-1) were observed in control plants. There were positive correlation (p≥0.01) between zinc content and chlorophyll a, chlorophyll b, chlorophyll a+b and carotenoid. Zinc content also had positive and significant correlation (p≥0.01) with stomata conductance, CO2 under stomata, transpiration rate, net photosynthesis and light use efficiency. So, providing zinc by foliar application with 1 and 1.5 g.l-1 nano zinc chelate and 1.5 g.l-1 zinc sulfate can lead to increase in chlorophyll and carotenoid contents. Increase in net photosynthesis may be due to higher photosynthesis pigments and also stomata conductance and CO2 under stomata. In the other hand, zinc is an essential micronutrient that acts either as a metal component of various enzymes or as a functional, structural, or regulatory cofactor such as carbonic anhydrase, ribulose 1, 5-bisphosphate carboxylase/oxygenase and fructose-1, 6-bisphosphate, and is thus associated with saccharide metabolism and photosynthesis.
Conclusion: Although the highest amount of most measured traits was obtained in plants that treated with 1.5 g.l-1 nano zinc chelate, there were no significant difference between 1 and 1.5 g.l-1 nano zinc chelate and 1.5 g.l-1 zinc sulfate treatments for zinc content, stomata conductance, CO2 under stomata, transpiration rate, net photosynthesis, water use efficiency and light use efficiency. Therefore, in order to increase zinc content and photosynthetic traits of holy basil, foliar application of with 1.5 g.l-1 zinc sulfate is recommended.
Sakineh Hasanzadeh; Fariborz Habibi; Mohammad Esmaeil Amiri
Abstract
Introduction: Pomegranate (Punica granatum L.) belongs to the Punicaceae family and grows in subtropical and Mediterranean climates. Nowadays the widespread usage of inorganic fertilizers has increased and so people concern about their health. The use of organic fertilizer instead of inorganic fertilizers ...
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Introduction: Pomegranate (Punica granatum L.) belongs to the Punicaceae family and grows in subtropical and Mediterranean climates. Nowadays the widespread usage of inorganic fertilizers has increased and so people concern about their health. The use of organic fertilizer instead of inorganic fertilizers is one of the methods of preserving health. Pomegranate is one of the most important products of Iran. This fruit plant is cultivated in some regions in arid and semi-arid areas. Due to the long growing season of pomegranate, droughtstress is one of the main limiting factors in the development of pomegranate orchards in Iran. Utilization of amino acids can help to increase efficiency and improve the quality of the fruit under environmental stress. Thus, this study aims to findany possibility to increase the production and quality of the fruit during the drought. The goalof this study was to study the effect of organic Aminol-Forte fertilizer on physiological and biochemical responses of pomegranate cv. Naderi under drought stress conditions.
Materials and Methods: This research was carried out in AbShirin field located on the old road 40 km from Qom-Kashan during 2011. Asplit plot experiment based on randomized complete block design was conducted with two factors, irrigation treatment in three levels (100% required water, 75% required water and 50% required water) and Aminol-Forte fertilizer treatment in four levels (0, 2, 3 and 4 ml/l). Spraying was conducted in four stages (pre-anthesis, after fruit set, fruit growth andtwo weeks per-harvest). In the end of the experiment, chlorophyll index, soluble sugars, insoluble sugars, proline, canopy degree and stomatal conductance were measured. Statistical analysis was performed using SPSS 17 program. Means were separated according to the Duncan’s multiple range test (DMRT) at 0.01 level of probability.
Results and Discussion: Analysis of variance of Aminol-forte fertilizer spraying on physiological and biochemical responses of pomegranate cv. Naderi under drought stress conditions showed that between irrigation treatment for chlorophyll index, proline and stomatal conductance were significant at 1% level of probability, and at 5% level of probability soluble sugarand insoluble sugar and canopy degree were significant. Fertilizer treatment at 1% level of probability was significant for proline and at 5% level of probability was significant for soluble sugars. Interaction was significant for soluble sugars, proline and canopy degree. Means showed that by increasing fertilizer level, soluble sugars content, proline and stomatal conductance significantly increased insoluble sugars and chlorophyll index decreased insignificantly. By decreasing irrigation levels, chlorophyll index, soluble sugars and proline significantly increased, meanwhile insoluble sugars and stomatal conductance significantly decreased. The highest chlorophyll index (65.44 SPAD) and the lowest chlorophyll index (56.48 SPAD) were obtained in 75% required water with 2 ml/l of fertilizer level and 100% required water with 3 ml/l of fertilizer level, respectively. The highest soluble sugars (14.94 mg/g) and the lowest soluble sugars (11.64 mg/l) were obtained in 50% required water with 0 ml/l of fertilizer level and 100% required water 2 ml/l of fertilizer level, respectively. The highest insoluble sugars (9.99 mg/g) and the lowest insoluble sugars (6.82 mg/l) were measured in 100% required water with 3 ml/l of fertilizer level and 50% required water with 2 ml/l of fertilizer level, respectively. The highest proline content (2.51μmol/l) and the lowest proline content (1.05μmol/l) were obtained in 50% required water with 4 ml/l of fertilizer level and 100% required water with 0 ml/l of fertilizer level, respectively. The highest canopy degree (-7.31˚c) and the lowest canopy degree (-9.38˚c) were measured in 50% required water with 4 ml/l of fertilizer level and 100% required water with 4 ml/l of fertilizer level, respectively. The highest stomatal conductance (38.23 mmol/m2/s) and the lowest stomatal conductance (9.7 mmol/m2/s) were obtained in 50% required water with 2 ml/l of fertilizer level and 100% required water with 3 ml/l of fertilizer level, respectively.
Conclusion: By increasing the level of Aminol-Forte fertilizer from 0 to 4 ml/l, soluble sugars content, proline and stomatal conductance significantly increased meanwhile insoluble sugars and the chlorophyll index decreased. Drought stress increased soluble sugars content, chlorophyll index, canopy degree and proline but, insoluble sugars and stomatal conductance decreased. According obtained results, it can be said, spraying of Aminol-Forte fertilizer containing amino acid could significantly reduce the negative effects of drought stress. In this study, the best results in terms of stress and no stress were obtained in 3 and 4 ml/l of Aminol-Forte fertilizer.
F. Habibi; M.E. Amiri
Abstract
In this experiment, physiological responses of two citrus rootstocks [sour orange (Citrus aurantium L.) and trifoliate orange (Poncirus trifoliata Raf.)] were investigated under in vitro salt stress conditions. This study was conducted on a completely randomized factorial design. Explants (Nucellar seedling ...
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In this experiment, physiological responses of two citrus rootstocks [sour orange (Citrus aurantium L.) and trifoliate orange (Poncirus trifoliata Raf.)] were investigated under in vitro salt stress conditions. This study was conducted on a completely randomized factorial design. Explants (Nucellar seedling obtained from seeds) of both rootstocks were transferred to Murashige and Skoog (MS) solid proliferation medium containing 8.9 µM BA and 0.5 µM NAA with different concentrations 0, 50, 100, 150, 200 mM of sodium chloride (NaCl) whit six replicates. Results show that leaf chlorophyll index, photosynthesis rate, stomatal conductance, internal CO2 concentration (Ci), total protein content decreased in both rootstocks by increasing salinity levels, although there was no significant difference for above-mentioned characteristics in the interaction of salinity and rootstock. The amounts of reduction in total protein content, chlorophyll loss and internal CO2 concentration (Ci), in trifoliate orange genotype were greater than the sour orange. Also, peroxidase enzyme activity increased by increasing salinity level in both rootstocks, but, the rate of increase in the trifoliate orange was higher than the sour orange. By increasing salinity levels in the cultural medium, the uptake of sodium (Na+) and chlorine (Cl-) significantly increased in both rootstocks over 6 weeks culture period. Comparison in to trifoliate orange, sour orange less sodium and chlorine were taken up. Based obtained results, can be declared, salt tolerance has a negative correlation with Na+ and Cl- content in plant tissues, and the plant have a less Na+ and Cl- in tissues are more resistant. Thus, sour orange was more tolerant than trifoliate orange to salt stress and could be has more resistant to high concentration salinity.
