Plant Growth Quality Research Articles

Comparing the Genetic Parameters of Three Rice Varieties on Suboptimal Land Using the SRI Method

The conversion of fertile land into industrial areas and construction development has contributed to the decline of rice production in Indonesia. Therefore, it is necessary to expand the rice fields to the sub-optimal land, i.e. lands with high levels of Fe and Al and low soil pH. One of the solutions that can potentially solve the problem is choosing varieties of rice that can adapt to the suboptimal land environment; the rice varieties can be obtained by estimating rice genetic parameters and selecting the optimal planting methods. One method that can potentially improve rice yield is “System of Rice Intensification”, or SRI method. Our study was conducted in the rice fields on suboptimal land at Pasar Ambacang, Kuranji District, Padang, Sumatra, from December 2019 to April 2020. The aims of the experiment are to determine the genetic parameters and responses of the three rice varieties to suboptimal land using the SRI method. A complete randomized design with four replications was used to set up the experiment using three varieties of rice, i.e. “Batang Piaman”, “Bujang Marantau”, and “IPB3S”. Based on the plant growth measurement and analysis of the genetic parameters, we found that the plant growth characters, particularly height and panicles length, had high heritability and genetic progression values.

Harnessing biofertilizer from human urine via chemogenic and biogenic routes: Synthesis, characterization and agronomic application

This study aimed at recovering nutrients from human urine as valorized products through chemical and biological mineralization, and assessing their fertilizer potential. Chemosynthesis of struvite (MgNH 4 PO 4 ⋅ 6H 2 O) was accomplished from fresh human urine through chemical mineralization using magnesia, whereas biogenic synthesis was achieved through microbial mineralization by employing a wastewater bacterium ( Pseudomonas aeruginosa KUJM KY355382.1). Elemental analysis and other characterization results confirmed the synthesized products as struvite under both chemical and biological synthesis methods. The potential of the chemogenic and biogenic struvite products as slow release fertilizer was reflected in improved plant growth characteristics, including height, fresh weight, dry weight, pod length and seed yield, of cowpea ( Vigna unguiculata ) compared to the control set. Specially, the seeds obtained per plant were 137.71 and 125.14% higher after application of chemogenic and biogenic struvite, respectively, compared to a no-fertilizer control. When assessing aging effect on struvite’s chemical structure by comparing a 15-year old struvite crystal with the recently synthesized biomineral, the weathered struvite was found to lose NH 4 + however, retain PO 4 3 − and Mg 2 + , implying its phosphate supplying potential over a long period. Both the chemogenic and biogenic synthesis routes successfully converted human urine to fertilizer (‘waste into wealth’), but the struvite yield was higher in the case of chemogenic synthesis using magnesia (474 ± 9.64 mg L −1 ) than biogenic synthesis employing Pseudomonas aeruginosa KUJM (345 ± 6.08 mg L −1 ). Still, the biogenic synthesis is preferred over the chemogenic route because the process is more eco-friendly. • Biogenic and chemogenic ways for producing biofertilizer from human urine were compared. • Both chemo- and biogenic struvite are potential biofertilizers. • Weathered struvite retains phosphorus fertilizing potential for a longer period. • Biogenic struvite outcompetes chemogenic struvite in ecofriendliness and biofertilizer performance.

Variations in Plant Growth Characteristics Due to Oxygen Plasma Irradiation on Leaf and Seed

Gene expression variations of plant leaf are investigated by irradiating seed and leaf with oxygen or air plasmas. Enhancement of leaf growth is induced by oxygen plasma irradiation on seeds, which is supported by increased gene expression for protein synthesis, oxidative-reduction reactions, and decreased gene expression concerning DNA methylation and histone modification. Suppression of leaf growth is observed by the oxygen plasma, which would be owing to increased gene expression concerning heat shock protein and redox reaction, and decreased expression of photosynthesis and glycoprotein. Moreover, gene expression variation due to air plasma irradiation is almost the same as that of oxygen plasma. Active oxygen species are major factors in both oxygen and air plasmas for the variation of gene expressions in plants.

Optimum Selection of Soil-Reinforced Herbaceous Plants Considering Plant Growth and Distribution Characteristics

Optimum Selection of Soil-Reinforced Herbaceous Plants Considering Plant Growth and Distribution Characteristics

The Effects of Suaeda salsa/Zea mays L. Intercropping on Plant Growth and Soil Chemical Characteristics in Saline Soil

Halophytes possess the capacity to uptake high levels of salt through physiological processes and their root architecture. Here, we investigated whether halophyte/non-halophyte intercropping in saline soil benefits plant growth and contains root-dialogue between interspecific species. Field and pot experiments were conducted to determine the plant biomasses and salt and nutrient distributions in three suaeda (Suaeda salsa)/maize (Zea mays L.) intercropping systems, set up by non-barrier, nylon-barrier, and plastic-barrier between plant roots. The suaeda/maize intercropping obviously transferred more Na+ to the suaeda root zone and decreased salt and Na+ contents. However, the biomass of the non-barrier-treated maize was significantly lower than that of the nylon and plastic barrier-treated maize. There was lower available N content in the soil of the non-barrier treated groups compared with the plastic barrier-treated groups. In addition, the pH was lower, and the available nutrient content was higher in the nylon barrier, which suggested that rhizospheric processes might occur between the two species. Therefore, we concluded that the suaeda/maize intercropping would be beneficial to the salt removal, but it caused an adverse effect for maize growth due to interspecific competition, and also revealed potential rhizospheric effects through the role of roots. This study provides an effective way for the improvement of saline land.

Insights in nodule-inhabiting plant growth promoting bacteria and their ability to stimulate Vicia faba growth

ABSTRACT The knowledge of the root nodule microbiome is still beyond the minimum. This study has been designed to isolate and characterize plant growth promoting bacteria and testing their ability to promote plant growth. In addition to Rhizobium MAP7, four other strains have been isolated from Phaseolus vulgaris nodules, and they have been molecularly identified as Bacillus MAP3, Brevibacillus MAP4, Pseudomonas MAP5, and Pseudomonas MAP8. The obtained strains showed the ability to produce IAA, siderophores, and HCN with different capabilities. A pot experiment was conducted to investigate the effect of the obtained strains on the physical growth parameters of Vicia faba. The inoculation with Rhizobium MAP7 along with Brevibacillus MAP4 and Pseudomonas MAP5 led to four times increase in the number of nodules (57/plant) compared with that of the control in addition to a significant increase in the physical growth parameters . Additionally, different nitrogen fractions increased significantly in response to this inoculum (226 and 206 mg/g dry weight total nitrogen for shoot and root respectively compared with 175 and 92.5 for control plants). The obtained strains in this study showed a good potentiality as plant growth promotors that might be tried with further crops on wider scale.

Melatonin and KNO3 Application Improves Growth, Physiological and Biochemical Characteristics of Maize Seedlings under Waterlogging Stress Conditions.

Simple SummaryWaterlogging is one of the serious abiotic stresses that retards plant growth and reduces crop productivity. Therefore, exploring effective ways for alleviating the impacts of waterlogging stress has important theoretical and practical applications. Melatonin is a pleiotropic molecule that influences many diverse actions to enhance plant growth. Therefore, investigating efficient waterlogging mitigation measures has both theoretical and practical significance. The objectives of the present research were to examine the efficiency of melatonin and KNO3 seed soaking and foliar application on alleviating the waterlogging inhibited growth performance of maize seedlings. The results showed that melatonin and KNO3 significantly improved the plant growth and biochemical parameters of maize seedlings under waterlogging stress conditions. Overall, the application of 100 µM melatonin with 0.50 g KNO3 via seed soaking and foliar spray can be used as a potential mitigating strategy for improving the growth of maize seedlings and alleviating the ill effects of waterlogging stress.Waterlogging is one of the serious abiotic stresses that inhibits crop growth and reduces productivity. Therefore, investigating efficient waterlogging mitigation measures has both theoretical and practical significance. The objectives of the present research were to examine the efficiency of melatonin and KNO3 seed soaking and foliar application on alleviating the waterlogging inhibited growth performance of maize seedlings. In this study, 100 µM melatonin and different levels (0.25, 0.50 and 0.75 g) of potassium nitrate (KNO3) were used in seed soaking and foliar applications. For foliar application, treatments were applied at the 7th leaf stage one week after the imposition of waterlogging stress. The results showed that melatonin with KNO3 significantly improved the plant growth and biochemical parameters of maize seedlings under waterlogging stress conditions. However, the application of melatonin with KNO3 treatments increased plant growth characteristics, chlorophyll content, and the net photosynthetic rate at a variable rate under waterlogging stress. Furthermore, melatonin with KNO3 treatments significantly reduced the accumulation of hydrogen peroxide (H2O2) and malondialdehyde (MDA), and it decreased the activity of pyruvate decarboxylase and alcohol dehydrogenase, while increasing enzymatic activities and soluble protein content of maize seedlings under waterlogging stress conditions. Overall, our results indicated that seed soaking with 100 µM melatonin and 0.50 g KNO3 was the most effective treatment that significantly improved the plant growth characteristics, chlorophyll content, photosynthetic rate, and enzymatic activity of maize seedling under waterlogging conditions.

Selenium Biofortification of Lettuce Plants (Lactuca sativa L.) as Affected by Se Species, Se Rate, and a Biochar Co-Application in a Calcareous Soil

Selenium biofortification of lettuce plants was studied for two rates (5 and 10 mg kg−1 soil) of either selenate or selenite and for the effect of 5% w/w biochar addition. Lettuce seedlings were grown in pots containing 1 kg of a calcareous soil. Twelve weeks later, the plants were harvested and selenium (Se), phosphorus (P), and sulfur (S) concentrations were determined in heads and roots. Plant growth characteristics were measured and plant biometrics were assessed by NDVI, NDRE, and SPAD measurements. The highest Se concentration of 315.19 mg kg−1 D.W. and the highest amount of Se taken up by plants (950.5 μg/pot) were observed for the low selenate rate with biochar. The corresponding values for selenite treatments were an order of magnitude lower. Although in general, minor to severe toxicity symptoms occurred with selenium application in no biochar treatments (except selenite low rate), the addition of biochar secured plant growth and increased S and P concentrations in plants, regulating Se uptake by plants at high selenite rate and allowing maximum plant uptake at the low selenate rate. To propose an appropriate Se fertilization rate, the fate of excess selenates in the soil environment should be examined and experimentation under soil conditions is necessary.

Effect of Organic and Synthetic Mulches on Soil Temperature, Nutrient Availability and Yield of Squash

The field experiment was conducted on squash cv. Bulam house at Central Research Farm, Bangladesh Agricultural Research Institute, Gazipur under AEZ-28 during rabi season of 2019-2020 and 2020-2021 to study the effect of organic and synthetic mulches on soil temperature, nutrient availability and yield of squash.The treatments were T1: control, T2: black polyethylene mulch, T3: white polyethylene mulch and T4: rice straw mulch. The experiment is laid out in a Randomized Complete Block Design (RCBD), where each treatment was replicated thrice. Data on growth and yield attributes of squash were collected during the crop growing season and after harvesting. Soil temperatures were differentially affected by the type of polyethylene mulch, with temperatures generally following the order: white polyethylene mulch>rice straw mulch>black polyethylene mulch. All plant growth characters, yield and yield contributing characters were superior with white polyethylene relative to grown without mulch (control). Treatment T3 (white polyethylene mulch) resulted in increased single fruit weight (kg) of squash than control. Fruit yield was also increased when grown in soil under white polyethylene mulch i.e. 37.6 tha-1. White polyethylene mulch had 282 % increase in yield per ha over control. The higher yield was associated with higher soil temperature in white polythene mulch compared to other mulches during crop growing period

Efeitos de diferentes níveis de nitrogênio sobre o crescimento vegetativo e produtividade do café conilon (Coffea canephora)

ABSTRACT: The determination of nitrogen in plants by techniques that allow a fast diagnosis, based on plant growth characteristics, can be a useful tool for the nutritional management of coffee plants. Thus, this study evaluated growth and yield characteristics of irrigated conilon coffee in response to different nitrogen levels, resulting in the determination of the minimum N levels required to achieve the maximum yield, here called critical levels. The experiment was carried out in Colatina, Espirito Santo, Brazil, on plantations of conilon coffee, clonal variety Emcapa 8111, genotype 02. Six nitrogen levels were applied (0, 110, 220, 440, 880 and 1320 kg N ha-1) and the response in growth and yield characteristics periodically evaluated. There was a positive effect of the increasing N levels on yield, in that the N levels that provided 95% of the maximum yield (137.4 bags ha-1 and 108.5 bags ha-1) in the 2012/2013 and 2013/2014 growing seasons, respectively, were 420.7 and 543.1 kg N ha-1. There was also a positive effect of N levels on the growth characteristics and nitrogen contents, indicating their use as tools for a rapid nutritional diagnosis, with a view to optimizing the nitrogen management in Conilon coffee.

Selenium uptake by rocket plants (Eruca sativa) grown in a calcareous soil as affected by Se species, Se rate and a seaweed extract-based biostimulant application

To investigate the potentiality of Eruca sativa (rocket) to be enriched in selenium (Se) and, thus, to promote human health through consumption, a pot experiment was designed. Two rates, 5 and 10 mg/kg soil, of either selenite or selenate sodium salts were applied to appropriate pots, each filled with 1 kg of calcareous soil. Rocket seedlings were transplanted and grown in these pots, and to half of the pots the biostimulant Actiwave was added. Twelve weeks later, the plants were harvested and Se concentrations determined in shoots and roots. Plant growth characteristics were measured and plants biometrics were assessed by soil plant analyses development (SPAD), normalised difference vegetation index (NDVI) and normalised difference red edge (NDRE). Sulfur (S) and phosphorus (P) concentrations in plant samples were also determined to discuss possible interactions among the three elements. The highest Se concentration of 1070.5 mg/kg dry weight (DW) was observed for the high selenate rate without biostimulant, placing rocket in the group of Se hyperaccumulator plants. Toxic effects were recorded for the plants that received the high selenate rate, whereas no toxicity symptoms were observed for either selenite rate. According to Se concentrations in controls, biostimulant application significantly suppressed Se uptake and significantly increased S and P uptake. The same negative biostimulant effect on Se concentration in plants was clear in selenate treatments. When the results were expressed as total uptake (mg/pot), positive correlations among Se, S and P were found for selenate treatments, whereas for selenite treatments, the opposite was observed. Impressively, 1.6 mg Se/pot on a DW basis was accumulated in rocket shoots in the low selenate-rate without biostimulant treatment, corresponding to approximately 30% of the added 5 mg of selenate.

Effect of plant age on development of root-knot nematode (M. javanica) on coriander

Coriander is one of the most important and nutritive seed spice crops grown all over the world. The production of coriander is affected by various biotic and abiotic factors. Among the diseases of coriander, nematode diseases are also most important. Root-knot nematodes are dangerous and economically very important pest of cultivated crops in the world. In view of this, a pot experiment was conducted to test the effect of plant age on development of Meloidogyne javanica on coriander.The pots were filled with sterilized sandy loamy soil. Root-knot nematodes (J2 stage) were inoculated in each pot at the time of germination, 7, 14, 21 and 28 days after germination.Results showed that as the nematode inoculum interval after germination was extended, the plant growth characteristics were also greatly improved. Similarly, increased nematode inoculum interval after germination considerably reduced nematode reproduction. But, No. of eggs/egg mass was found almost similar in among all plant ages (i.e., from at the time of germination, 7, 14, 21 and 28 days after germination).

Effect of organic fertilizers and spraying with potassium nanoparticals on some growth characteristics of maize plant {Zea mays L.}

Effect of organic fertilizers and spraying with potassium nanoparticals on some growth characteristics of maize plant {Zea mays L.}

Effect of some medicinal and algal extracts on some vegetative and biochemical growth characteristics of sunflower plants under water stress conditions

Effect of some medicinal and algal extracts on some vegetative and biochemical growth characteristics of sunflower plants under water stress conditions

Mycorrhiza improves plant growth and photosynthetic characteristics of tea plants in response to drought stress

Tea plants are sensitive to soil moisture deficit, with the level of soil water being a critical factor affecting their growth and quality. Arbuscular mycorrhizal fungi (AMF) can improve water and nutrient absorption, but it is not clear whether AMF can improve the photosynthetic characteristics of tea plants. A potted study was conducted to determine the effects of Claroideoglomus etunicatum on plant growth, leaf water status, pigment content, gas exchange, and chlorophyll fluorescence parameters in Camellia sinensis cv. Fuding Dabaicha under well-watered (WW) and drought stress (DS) conditions. Root mycorrhizal colonization and soil hyphal length were significantly reduced by the eight-week DS treatment. AMF inoculation displayed a significant increase in shoot and root biomass production. The relative water content, leaf water potential, nitrogen balance index, pigment content, maximum photometric effect (Fv/Fm, QY_max), and steady-state photometric effect Y (II) (QY_Lss) decreased dramatically, while the leaf water saturation deficit and steady-state non-photochemical fluorescence quenching (NPQ_Lss) generally increased under DS conditions. Mycorrhizal treatment induced significantly higher relative water content, leaf water potential, nitrogen balance index, pigment (chlorophyll, flavonoid, and anthocyanin) content, net photosynthesis rate, transpiration rate, stomatal conductance, intercellular CO2 concentration, QY_max, and QY_Lss; however, it resulted in a lower leaf water saturation deficit and NPQ_Lss under both WW and DS conditions, as compared with non-mycorrhizal plants. These results imply that AMF promoted tea plant growth and alleviated negative effects of DS by promoting gas exchange, regulating the water status of leaves, and regulating photosynthetic parameters.

Drought Stress Amelioration in Maize (Zea mays L.) by Inoculation of Bacillus spp. Strains under Sterile Soil Conditions

The aim of the present study was to promote plant growth characteristics including mineral uptake and various phytohormone production by indigenously isolated Bacillus spp. strains. Plants subjected to normal and water stress conditions were collected after 21 days to measure physiological parameters, photosynthetic pigment estimation, biochemical attributes, lipid peroxidation and antioxidant enzyme response modulation. Our results correlated with drought stress amelioration with the inoculation of Bacillus spp. strains BEB1, BEB2, BEB3 and BEB4 under sterile soil condition. Inoculated plants of both maize cultivars showed increases in fresh (56.12%) and dry (103.5%) biomass, plant length (42.48%), photosynthetic pigments (32.76%), and biochemical attributes with enhanced nutrient uptake. The overall maize antioxidant response to bacterial inoculation lowered the malonaldehyde level (59.14%), generation of hydrogen peroxide (45.75%) and accumulation of flavonoid contents in both control and water stress condition. Activity of antioxidant enzymes, catalase (62.96%), peroxidase (23.46%), ascorbate peroxidase (24.44%), and superoxide dismutase (55.69%) were also decreased with the application of bacterial treatment. Stress amelioration is dependent on a specific plant–strain interaction evident in the differences in the evaluated biochemical attributes, lipid peroxidation and antioxidant responses. Such bacteria could be used for enhancing the crop productivity and plant protection under biotic and abiotic stresses for sustainable agriculture.

The occurrence of rhizobacteria from Paspalum genotypes and their effects on plant growth

This work aimed to isolate and characterize plant growth promoting rhizobacteria (PGPR) from 10 Paspalum genotypes and evaluate the effect of their inoculation on P. regnellii, P. atratum, and P. malacophyllum genotypes. The bacterial population ranged from undetectable to 107 bacterial cells per gram of fresh matter in the Paspalum genotypes. Initially, we isolated 164 bacteria from rhizospheric soil and roots of the Paspalum genotypes using media N-free LG agar plate, semi-solid NFb, and LGI. The isolates were characterized genetically and physiologically. The sequencing of 16S rRNA showed the presence of many genera, and some are new in association with Paspalum. The most common was Bacillus followed by Rhizobium, Paraburkholderia, Enterobacter, Cupriavidus, Pseudomonas, Dyadobacter and Acinetobacter. Thirty-eight per cent of isolates produced siderophores, 25 % produced solubilized phosphate, and only 9 % produced indolic compounds. Three greenhouse experiments were performed in randomized blocks with six replicates using representative bacterial strains isolated from P. regnellii, P. malacophyllum and P. atratum cv. Pojuca. We also included strain Sp245 (Azospirillum baldaniorum), uninoculated control, and nitrogen control (150 kg N ha−1). There was an increase of up to 53 % in shoot dry matter in P. regnellii inoculated with strain Sp245 and the shoots accumulated more N. In contrast, only small effects were observed for the other Paspalum genotypes inoculated with PGPR from the host genotypes. This study shows a high diversity of diazotrophic rhizosphere bacteria and suggests no strain specificity between the bacterial isolates and the Paspalum genotypes.

Effect of container size and types on the root phenotypic characters of Capsicum

Capsicum genus comprised of several cultivars is considered as an important spice crop worldwide. Roots play a vital role in a plant to mine water from the deeper layers of the soil. Although, characterisation for root traits have been made using different containers in many crops, such efforts for phenotyping root characteristics in Capsicum species are limited. Therefore, the experiment was initiated to find out the influence of container size on root characteristics and also to identify the appropriate container for high throughput phenotyping of Capsicum species for desirable root characteristics. Nine genotypes belonging to different Capsicum spp. were grown in three types of containers having different dimensions. Among the three types of containers, the bucket type container with dimension of 32 cm height 30 cm diameter with 23 kg soil media capacity was most suitable for phenotyping root characteristics compared to PVC pipe and pot type. Subsequently, 18 genotypes were phenotyped for plant growth and root characteristics in the bucket type container. The genotypes IHR 4517, IHR 3529, IHR 4501, IHR 4550, IHR 4491 and IHR 3241 with better root characteristics were identified.

Application of Cyanobacteria (Roholtiella sp.) Liquid Extract for the Alleviation of Salt Stress in Bell Pepper (Capsicum annuum L.) Plants Grown in a Soilless System.

Salinity is one of the abiotic stresses that affect crop growth and productivity in arid and semi-arid regions. Unfortunately, there are few known methods to mitigate the deleterious impacts of salt stress on the development and yield of vegetable crops. Blue-green algae (cyanobacteria) are endowed with the potential to curb the negative impacts of salt stress as they are characterized by biostimulant properties. The present work aimed to investigate the effects of Roholtiella sp. as a foliar extract on the growth characteristics, physiological and biochemical responses of bell pepper (Capsicum annuum L.) plants under varying levels of salinity conditions. A soilless water experiment was carried out in a greenhouse where bell pepper seedlings were grown under five salt concentrations (0, 50, 200, 150, and 200 mM of NaCl). Growth characteristics, pigments content, relative water content, and antioxidant activity (CAT) were determined. Our results showed that growth parameters, relative water content (RWC), chlorophyll a & b concentrations under salinity conditions were negatively affected at the highest concentration (200 mM). Interestingly, the application of Roholtiella sp. foliar extract enhanced the plant growth characteristics as shoot length increased by 17.014%, fresh weight by 39.15%, dry and weight by 31.02%, at various salt treatments. Moreover, chlorophyll a and b increased significantly compared with seedlings sprayed with water. Similarly, RWC exhibited a significant increase (92.05%) compared with plants sprayed with water. In addition, antioxidants activities and accumulation of proline were improved in Roholtella sp. extract foliar sprayed seedlings compared to the plants foliar sprayed with water. Conclusively, at the expiration of our study, the Rohotiella sp. extract-treated plants were found to be more efficient in mitigating the deleterious effects caused by the salinity conditions which is an indication of an enhancement potential of tolerating salt-stressed plants when compared to the control group.

Improvement of salt tolerance in Stevia rebaudiana by co-application of endophytic fungi and exogenous spermidine

Stevia (Stevia rebaudiana Bertoni) is an important and salt-sensitive medicinal plant used as a natural sweetener in food products. In this work, we used a pot experiment to investigate the role of microbial inoculation and exogenous polyamine spermidine (Spd) in conferring salt stress tolerance in stevia by analyzing plant growth, chlorophyll (Chl) content, Chl a fluorescence, antioxidant defense system and steviol glycosides. The inoculated plants with Piriformospora indica (Pi), Tricuderma virens (Trich) or Pi+Trich were grown in optimum conditions. At the late of vegetative stage (BBCH growth stage 47), plants sprayed with different concentrations of Spd (0, 0.75, and 1.5 mM) and then were exposed to salinity stress by irrigation with saline treatments (mix of Caspian Sea and distilled water; 0, 6, and 12 dS m−1). The results revealed that salt stress increased hydrogen peroxide (H2O2) and lipid peroxidation (Malondialdehyde: MDA), and consequently plant growth characteristics and maximum photochemical quantum yield of PSII (Fv/Fm) as well as Chl content decreased, but antioxidant enzymes activity including superoxide (SOD), catalase (CAT), peroxidase (POD), and ascorbate peroxidase (APX) increased in the plants. Exposure to moderate salinity increased stevioside (Stv) and rebaudioside A (Reb A) content, while these compounds were decreased in the presence of severe salinity. The endophytic symbiosis and foliar spray of Spd (especially in Pi+Trich and Spd 0.75 mM) mitigated salt stress by significant increases in antioxidant enzymes activity and a decrease in H2O2 content and lipid peroxidation. Inoculation with Pi, Trich, and especially Pi+Trich increased the Chl content, Fv/Fm, shoot dry weight, and Stv and Reb A content at all salinity levels. Consequently, combined inoculation of Pi and Trich and foliar application of Spd can be a good approach to improve tolerance, growth and steviol glycosides production of stevia in salt stress conditions.