Pistachio Seedlings Research Articles

Survey, Pathogenicity assay, and Molecular Identification of the Pathogenic Fungi Associated with Pistachio in Anbar Province, Iraq

This study was carried out in 6 different locations in the Anbar Province, between January and February 2021. The locations with higher pistachio cultivation, such as Kabisa, Al-Haditha, Al-Baghdadi, Anah, Al-Qaim, and Rawa were selected to study the prevalence of fungal diseases affecting pistachio crops. Twenty-six distinct fungal isolates were identified, and each isolate was examined for the pathogenicity. Although the level of pathogenicity of each isolate varied from high to moderate, they all caused lesions, damaged vascular tissue, signs of root rot and seed rot in pistachio seedlings. The fungal strains were identified depending on ITS marker. Twelve of the isolates belonged to Fusarium solani, 10 of F. falciforme isolates, 2 of F. oxysporum isolates, while 1 isolate of F. vanettenii and Xylaria sp. The most frequently-occurring species were F. falciforme and F. solani in the Anbar Province. Out of all the studied isolates, Al-Qaim and Al-Baghdadi were the highest pathogenic isolates. The pathogenic effects of F. vanettenii and Xylaria sp. on pistachio plants as well as the existence of F. solani and F. falciforme in Iraq were all recorded in this study for the first time.

The Effect of Pistachio Waste Compost and Mycorrhizal Fungi on Vegetative Growth and Nutritional Status of Pistachio Seedlings in a Saline-Sodic Soil

The Effect of Pistachio Waste Compost and Mycorrhizal Fungi on Vegetative Growth and Nutritional Status of Pistachio Seedlings in a Saline-Sodic Soil

Vermicompost and/or compost and arbuscular mycorrhizal fungi are conducive to improving the growth of pistachio seedlings to drought stress

Symbiosis with arbuscular mycorrhizal fungi (AMF) has a remarkable role in alleviating the stress caused by adverse conditions on the growth of host plants. The effectiveness of AMF is usually influenced by environmental variables and soil conditions. In the present study, we aimed to enhance soil conditions by compost and vermicompost, thereby affecting plant response to AMF under drought stress conditions. AMF communities were collected from pistachio (Pistacia vera) orchards in adverse conditions (i.e. dry and saline soils). Composts and vermicomposts were produced by Trichoderma longibrachiatum fungus and Amynthas gracilis worms, respectively. Pistachio seedlings were planted in the soil that was inoculated with native AMF and amended by compost or vermicompost. The experiment was conducted under drought stress or otherwise in well-watered conditions. Based on the results, drought stress decreased plant growth, Zinc (Zn), and phosphorus (P) uptake of pistachio seedlings. Vermicompost and compost had a noticeable effect on plant growth (37 % and 64 %) and nutrient uptake (67 % and 11 % P uptake and 138 % and 105 % Zn uptake) under well-watered. These effects were observed in plant growth (232 % and 29 %) and nutrient uptake (30 % and 52 % P uptake and 35 % and 1 % Zn uptake) under severe drought stress conditions. The highest percentage of root colonization by AMF was observed in plants that grew on soils amended with vermicompost. Zinc (39 %) and phosphorus (100 %) uptake increased by the effect of native AMF, while vermicompost and compost also enhanced nutrient uptake. The results of the present study strongly demonstrated that the use of composted materials improved pistachio seedling's response to native AMF under drought conditions, however, we are still far from understanding which mechanisms of AMF and/or organic fertilizer improved P and Zn uptake and growth of pistachio seedlings.

The Improvement of Growth, Water Relations, and Oxidative Reduction of Pistachio Rootstock in Drought Stress Conditions with Beta-Aminobutyric Acid Pretreatment

Environmental stresses are inevitable during the plant growth. The β-aminobutyric acid (BABA) induces systemic resistance in plants. The efficiency of BABA pretreatments (0.5 and 10 mM) in inducing drought tolerance in the ‘Akbari’ pistachio rootstock in controlled environmental conditions was investigated. The BABA solutions were sprayed three times every two days on pistachio seedlings at the 15-leaf stage. Subsequently, the irrigation of plants was withheld for 25 days, and the effects of BABA pretreatments on the growth, water relations, and oxidative damage indices in plants were investigated. The BABA pretreatments prevented the reduction of shoot dry and fresh mass under a drought stress by inhibiting the leaf abscission and maintaining the relative water content. Owing to the leaf abscission, leaf water potential and turgidity of drought-stressed plants were similar to the control plants. However, the measurement of osmotic potential indicated that the BABA pretreatments improved turgor potential in leaves of the drought-stressed plants by inducing osmotic regulation. A declined membrane stability index and chlorophylls, as well as the malondialdehyde accumulation in line with the hydrogen peroxide accumulation in the leaves, indicated the development of oxidative damage under drought. Still, the BABA pretreatment restricted the severity of oxidative damages. In this regard, a 5 mM BABA pretreatment was the most effective one in the anti-drought plant protection.

Interactive effect of salinity and Ca to Mg ratio of irrigation water on pistachio growth parameters and its ionic composition in a calcareous soil

ABSTRACT This study investigated the effect of different salinity (EC≈6 and 9 dS/m) and Ca/Mg ratios (≈0.95,0.50, and 0.25) in irrigation water on the chemical composition of soil solution and growth of pistachio (Pistacia vera L.). The physiological, biochemical, and yield-related responses of pistachio seedlings were measured within ≈30 weeks in a greenhouse pot experiment. The EC of the soil solutions rapidly approached the one in the irrigation waters while the Ca/Mg ratios slowly altered, as such the final ratios were ≈50-100% larger than the one in the irrigation waters. The slower change in the Ca/Mg ratio is due to the fact that Ca concentration is dominantly controlled by the calcite solubility but the Mg concentration by the ion-exchange reaction. With increasing EC of the soil solution from 5.8–10.4 dS/m, we found 4-fold reduction in shoot dry weight and 62% increase in electrolyte leakage. In each salinity level, the highest yield and membrane stability were achieved at the Ca/Mg ratio of ≈1 in the soil solution. Overall, a Ca/Mg ratio < 1 in the irrigation water shifted the ionic composition of the soil solution, even in calcareous soil, towards a ratio < 1 and negatively affected pistachio growth.

Tolerance to salinity and drought stresses in pistachio (Pistacia vera L.) seedlings inoculated with indigenous stress-tolerant PGPR isolates

Salinity and drought are two major abiotic stresses that limit plant growth and productivity through their adverse effects on diverse physiological processes in plants, especially their photosynthetic capacity. Application of indigenous stress-tolerant plant growth-promoting rhizobacteria (PGPR) is among the eco-friendly strategies employed to ameliorate the harmful effects of salinity/drought stresses on plants. The present study was carried out to investigate the effects of stress-tolerant PGPR isolates on vegetative growth, nutritional, and photosynthetic parameters of pistachio (Pistacia vera L.) seedlings (cv. Badami-Riz–e-Zarand) under salinity and drought conditions. A factorial greenhouse experiment was conducted as a completely randomized design with three replications for 28 weeks in 2019. The treatments consisted of PGPR inoculations (control: non-inoculated, and inoculation with Staphylococcus sciuri, Zobellella denitrificans, and Arthrobacter endophyticus), three salinity levels (0, 1000 and 2000 mg NaCl kg−1 soil), and three irrigation intervals (C: irrigated every two days; D1: four days and D2: six days). The results indicated that, under high levels of salinity and drought stresses (2000 mg NaCl kg−1 soil + six-day irrigation intervals), separate inoculation of pistachio seedlings with Arthrobacter endophyticus, Zobellella denitrificans and Staphylococcus sciuri significantly enhanced the shoot and root dry weight, leaf area, leaf number, shoot and root K+ concentration and relative water content (RWC), which were accompanied by decreases in shoot and root Na+ concentrations. Moreover, the combined salinity and drought stresses had a greater effect on reducing total chlorophyll (TChl), carotenoids, chlorophyll fluorescence index (Fv/Fm), net photosynthetic rate (PN), transpiration rate (E), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and water use efficiency (WUE), whereas application of the stress-tolerant PGPR isolates significantly increased these photosynthetic parameters compared to the non-inoculated seedlings at the corresponding stress levels. According to the results, the indigenous stress-tolerant PGPR isolates effectively improved the growth, physiological and photosynthetic parameters in pistachio seedlings subjected to salinity and drought stresses, which could be attributed to the local adaptation of the PGPR isolates as well as their plant growth-promoting properties that were unraveled in our in vitro studies, e.g. production of auxin, ACC-deaminase, siderophore, exopolysaccharides along with P/Zn solubilization activities.

Identification of some drought resistance mechanisms in four pistachio seedling rootstocks under water stress

Identification of some drought resistance mechanisms in four pistachio seedling rootstocks under water stress

Improving the Drought Tolerance in Pistachio (Pistacia vera) Seedlings by Foliar Application of Salicylic Acid

Improving the Drought Tolerance in Pistachio (Pistacia vera) Seedlings by Foliar Application of Salicylic Acid

Effect of Deficit Irrigation with Treated Wastewater on Water Use Efficiency, Nutrient Uptake, and Growth of Pistachio Seedlings in an Arid Area

Effect of Deficit Irrigation with Treated Wastewater on Water Use Efficiency, Nutrient Uptake, and Growth of Pistachio Seedlings in an Arid Area

Role of hydrogen peroxide pre-treatment on the acclimation of pistachio seedlings to salt stress

Oxidative stress, provided that a mild level is imposed, can benefit the plants latterly subject to stress. In the present work, acclimation of pistachio seedlings, which had previously been sprayed with different concentrations of hydrogen peroxide (H2O2) as an oxidative stressor, to salt stress was investigated. The plants, formerly treated with 0, 1, 5, or 10 mM H2O2, were subsequently imposed to NaCl stress (120 or 240 mM) for 7 days. The results revealed that the levels of ionic leakage, proline and reducing sugar in the leaves as well as the sodium and chlorine concentrations in the roots and the shoots were increased under salt stresses, while the chlorophyll and relative water content (RWC) were reduced. The exposure of the H2O2-pretreated seedlings to salt stress led to higher proline and reducing sugar contents, and greater RWC and chlorophyll compared with the seedlings only treated with salt. Pre-treating with H2O2 made the potassium uptake by the roots enhance. Conversely, the sodium content decreased, leading to a correspondingly lower Na+/K+ ratio. Thus, acclimation to salinity with a mild H2O2 stress seems to operate through an enhanced osmotic adjustment activity and improved ionic balance (Na+/K+ ratio) of pistachio seedlings. However, more studies need to be done, particularly at the molecular level, to boost our understanding of the mechanisms involved in H2O2-mediated, induced resistance to salt stress.

Anastomosis Groups and Pathogenicity of Rhizoctonia solani Kühn Isolates Obtained from Pistachio (Pistacia vera L.) Saplings in Siirt Province, Turkey

Pathogenicity and anastomosis groups of seven Rhizoctonia-like isolates obtained from infected pistachio (Pistacia vera L.) seedlings were determined, in the central district of Siirt province at Southeast Anatolia Region in Turkey. Browning on the crown root of the collected saplings and drying of plants were observed. In the pathogenicity test, the most virulent isolate was Rs2 with a disease severity of 93.75%. The anastomosis group of this isolate, which caused the saplings to dry completely was determined as Rhizoctonia solani AG-4. The moderately virulent Rs3 and Rs1 isolates were determined as the binucleate AG-F group. These two isolates caused yellowing of the seedling leaves and browning of the roots, however, the plants did not die and preserved their vitality to a certain extent. The R9 and R14 isolates identified as anastomosis group AG-F did not cause any symptoms on inoculated plants and on the negative control. The Rs7 and Rs10 isolates were identified as the anastomosis group AG-4 and were determined to be pathogenic in saplings. The results of this study are the first record for the virulence and anastomosis groups of Rhizoctonia species that cause root and crown root diseases in Siirt pistachio.

Study on cultivation of pistachio (Pistacia vera L.) seedlings in containers

This article highlights the results from the effect of changing the volume of containers on the growth and development of pistachio seedlings, as well as the effect of hydrogel, moisture-accumulating substances on the preservation of pistachio seedlings planted on plantations. According to the research, seedlings of pistachio, planted on containers 20x40 cm in size, reached an average height of 18.2 cm, an average diameter at the root collar of 4 mm and an average root length of 30.4 cm. Pistachio seedlings (planted in a permanent place) grown by this method reached safety 95%, which is 122% compared to control group. It is possible to maintain a high field moisture capacity for 2-3 years by adding moisture-accumulating substances - hydrogel to the soil. This allows retaining moisture sufficient for the preservation and growth of pistachios in dry conditions. The preservation of moisture is necessary for pistachio seedlings for good growth and development, branching, budding, to shorten the period of entry into fruiting and increase the yield. Studies, conducted on the effect of hydrogel on transplanted annual shows that the most effective rate is 100 grams/plant. At this application rate, the average plant growth was 20.5 cm, which is 113% compared to control group, the average growth of lateral branches is 6.5 cm, which is 118.0% compared to control group.

Pistachio (Pistachia vera L.) seedling growth response to irrigation method and volume in Iran

In Iran, pistachio (Pistachia vera L.) orchards are mostly irrigated by surface irrigation. In this research, the border surface irrigation method was compared to five different irrigation systems. The research was carried out for four years at the Pistachio Research Center of Iran (IPRC) in Rafsanjan. A split-plot design was used with six irrigation systems with main plots; surface, drip, subsurface porous pipe, bubbler, T-Tape, and pottery cylinder, and three subplots of 10%, 20% and 30% Class A Evaporation Pan (685, 1370 and 2055 m3 ha−1 year−1). Generally, seedling performance increased with level of irrigation. The best results for seedling height, trunk diameter, leaf number and leaf area were with the pottery cylinder and drip systems and the 30% irrigation treatment; the poorest results were with the surface and T-Tape systems and the 10% irrigation treatment. The highest salinity was with the subsurface system and the 10% irrigation treatment and the T-Tape system with the 10% and 20% irrigation treatments. The lowest salinity with the lowest irrigation treatment was with the pottery cylinder and drip system with the 20% and 30% irrigation treatments. The pottery cylinder system had the highest common thin roots at 60−90 cm, and the drip system had many thin roots at 30−60 cm. Overall, the pottery cylinder and drip systems were best for pistachio seedlings.

Effects of salinity and Ca:Mg ratio of irrigation water on pistachio seedlings phosphorus planted under greenhouse conditions.

Phosphorus (P) is a key element in many biological processes of plants and animals. We aimed to investigate the effect of different salinity levels and Ca:Mg ratios of irrigation water arid lands on soil available P, soluble P, and P absorbed by the pistachio plant. For this purpose, a greenhouse experiment was conducted by sowing the seeds of pistachio in a factorial randomized block design with four soil salinity levels (S1 (6 dS.m-1irrigation water salinity, leaching fraction (LF) = 50), S2, S3, and S4 (9 dS.m-1 irrigation water salinity, LF = 50, 30 and 20, respectively)) and three Ca:Mg ratios (M1, M2, and M3 equal to 1, 0.5, and 0.25, respectively). After harvesting the plants, the amount of soil available P (Po), water-soluble P (Pw), and total P (Pt) at soil depths of 0-5, 5-25, 25-50, and 50-75 cm, and P concentration in the leaves of Pistachio seedlings were measured.The results showed that the salinity of soil saturated extract had no significant effect on Po, Pw, and Pt. The reduction in Ca:Mg ratio increased Po and Pw in soil surface but it did not affect Pt. Increasing salinity from S1 to S2 augmented plant P uptake but at higher salinity levels, P uptake was reduced. The decrease in Ca:Mg ratio had no significant effect on plant P contents.

Exogenous melatonin mitigates the salinity damages and improves the growth of pistachio under salinity stress

This study investigated the ability of exogenous melatonin (MT) to alleviate salinity stress in pistachio seedlings (Pistacia vera cv. Badami-Zarand) in a controlled greenhouse. Seedlings were treated with different salinity levels (25, 50, and 100 and 150 mM). Foliar application of melatonin with 0, 25, 50, 75, 100, 125 and 150 μmol/L concentrations was applied two times during the seeding treated with the various salinity levels. The results indicated that the deleterious effects of MT application were observed when they were applied under non-stressful conditions (control). The greatest protective effect against simulated salinity stress was observed in 100 μmol/L of MT in 150 mM salinity levels. Melatonins markedly alleviated the inhibitory effects of salinity on root and shoot growth, chlorophyll level and ion leakage. Activities of antioxidant enzymes, proline content, endogenous polyamine and melatonin increased with exogenous application of MT in salinity stress condition. Exogenous melatonin was also associated with significant increases in the nutrient uptake. Therefore, exogenous melatonin can attenuate the salinity damage via enhancing anti-oxidation ability, osmotic activity-adjusting, nutrient uptake and polyamines biosynthesis.

The effects of foliar application of melatonin on some physiological and biochemical characteristics and expression of fatty acid desaturase gene in pistachio seedlings (Pistacia vera L.) under freezing stress

ABSTRACT In this study, the impacts of exogenous melatonin on freezing stress mitigation in pistachio (Pistacia vera L.) seedlings (30-days old) were investigated. Our results showed that in pistachio seedlings under freezing stress antioxidant enzyme activity, malondialdehyde (MDA) hydrogen peroxide (H2O2), electrolyte leakage, chlorophyll degradation, proline and soluble sugar and γ-aminobutyric acid (GABA) content increased. Phenolic component, phenylalanine ammonia lyase (PAL) activity and the expression of fatty acid desaturase (FAD2) gene increased whilst ascorbate and glutathione concentration significantly decreased in comparison with control. In this research, application of melatonin significantly reduced the antioxidant enzyme activity, MDA, H2O2, chlorophyll degradation, GABA concentration, soluble sugar, and proline contents under stress condition. In addition electrolyte leakage, PAL activity and transcripts of FAD2 gene markedly decreased when the leaves of pistachio seedlings sprayed with melatonin. The results of this study showed that MEL could alleviate the oxidative damages induced by freezing stress and to maintain the structure and mobility of cell membrane in pistachio seedlings under stress conditions. Considering that MEL is an inexpensive and safe bio-stimulator, it seems that MEL is a potential candidate that could be applied used to increase the resistant pistachio trees against variety of biotic and abiotic stresses in the field conditions.

Xylella fastidiosa causes leaf scorch of pistachio (Pistacia vera) in Iran

Since the early 2010s, pistachio (Pistacia vera L.) leaf scorch symptoms have been observed in orchards in several provinces in Iran. Seventeen of 83 symptomatic leaf samples from pistachio plants from 21 orchards were positive for the presence of Xylella fastidiosa, as detected by DAS-ELISA with X. fastidiosa-specific antibodies and by PCR assays with X. fastidiosa-specific primers. A Gram-negative bacterium similar to X. fastidiosa was isolated into solid media. DAS-ELISA and PCR confirmed the identity of the isolated bacteria as X. fastidiosa. Koch’s postulates were fulfilled by artificially inoculating isolates obtained from pistachio showing leaf scorch to healthy pistachio and Nicotiana tabacum (cv. White Burley). Selected isolates induced leaf scorch symptoms when inoculated on tobacco and pistachio seedlings grown under greenhouse conditions. Early leaf scorch symptoms appeared approx. 2 months after inoculation of tobacco and approx. 3 months for pistachio. Reisolation of X. fastidiosa from inoculated and symptomatic plants and DAS-ELISA and PCR tests confirmed the identity of the re-isolated bacteria to be X. fastidiosa. On the basis of disease symptoms, pathogen isolation, pathogenicity tests and positive diagnosis by DAS-ELISA and PCR, X. fastidiosa is concluded to be the causal agent of pistachio leaf scorch in Iran. This is the first report of isolation and pathogenicity of X. fastidiosa in pistachio worldwide.

Could indigenous arbuscular mycorrhizal communities be used to improve tolerance of pistachio to salinity and/or drought?

Arbuscular mycorrhizal fungi (AMF) establish symbiosis with a number of plant species, including pistachio, under a broad range of soil conditions. Here we present a fully factorial pot experiment where four different indigenous AMF communities (two with high- and two with low-salinity legacies) were tested for improving pistachio seedling tolerance to salinity and/or drought in terms of maintaining its growth and/or mineral (phosphorus and zinc) nutrition under experimentally applied abiotic stress. The AMF communities were pre-cultured with a grass to reduce the load of pistachio pathogens before application to the seedlings. We detected systematic improvement of pistachio mineral nutrition by the AMF communities, whereas salinity and drought generally suppressed pistachio performance independently of each other. The AMF communities from saline soils systematically improved pistachio tolerance to salinity in terms of maintaining higher phosphorus acquisition of their host, whereas their effect on maintaining plant zinc nutrition under high salinity was less prominent. The effects of the different AMF communities on pistachio tolerance to drought were variable and without obvious link to the environmental legacy of the AMF. One of the AMF communities from saline soil (dominated by Rhizophagus) showed particular tolerance to salinity in terms of maintaining high colonization rates of pistachio roots. Interestingly, one of the AMF communities from low-salinity soils conferred a significant tolerance of pistachio to salinity in terms of maintaining its phosphorus acquisition upon the stress. This means that beneficial traits of plant symbiotic microbes may occur uncoupled from the selective pressure in their native range.

Effect of planting dates and different growing media on seed germination and growth of pistachio seedlings

BackgroundSowing time and suitable planting media are considered basic requirements to get the maximum yield and high profit for their direct and significant impact on seedlings quality and productivity of trees later. So this experiment has been carried out in a private nursery at Gharbiya Governorate, Egypt, during the seasons of 2016 and 2017 to study the effect of seven growing media (GM): sandy soil 100%; sandy soil:peat moss:vermiculite (2:1:1) by volume; sandy soil:peat moss:vermiculite (1:2:1); loamy soil:sandy soil:vermiculite (2:1:1); loamy soil:sandy soil:vermiculite (1:2:1); loamy soil:peat moss:vermiculite (2:1:1); and loamy soil:peat moss:vermiculite (1:2:1). Ashoury pistachio seeds were planted on three different dates viz, 1 February, 20 February, and 10 March and their interaction on seed germination and growth of the resulting seedlings.ResultsThe results obtained from this study showed that the maximum germination percentage, number of leaves/seedling, stem diameter, root length, leaf fresh, and dry weight were recorded when the seed was planted on 10 March and seedlings growing in the loamy soil:sandy soil:vermiculite (2:1:1).ConclusionIt could be concluded that planting seeds of “Ashoury” pistachio on 10 March in growing media contains loamy soil:sandy soil:vermiculite (2:1:1) for maximum germination and growth of subsequent seedlings.

Fractionation and Speciation of Manganese in Rhizosphere Soils of Pseudomonas sp. Rhizobacteria Inoculated Pistachio (Pistacia vera L.) Seedlings Under Salinity Stress

ABSTRACTEnhancement of manganese (Mn) availability in saline and Mn-deficient soils is very important for plant growth. An experiment was carried out to evaluate the effect of Pseudomonas sp. rhizobacteria (P0 (control), P1, P2 and P3) and Mn (0 and 10 mg Mn kg−1 soil) on the distribution of Mn in the rhizosphere of pistachio seedlings under salinity stress (0, 1000 and 2000 mg NaCl kg−1 soil). The results showed that salinity decreased the dry weight, Mn uptake and chlorophyll content of the pistachio seedlings. However, inoculation with rhizobacteria increased these parameters in saline conditions. Application of rhizobacteria increased the availability of Mn in the rhizosphere soil. The use of rhizobacteria decreased the residual-Mn form in the rhizosphere. Inoculation with rhizobacteria increased the percent of Mn2+ and MnCl+ species in the soil solution. However, pistachio seedlings inoculation with rhizobacteria increased the contents of Mn available forms in the rhizosphere soil.