Highest Shoot Research Articles

Heavy Metal Co-Resistance with Antibiotics amongst Plant Growth Promoting Bacteria Isolates from Rhizosphere of Nypa Fruticans

Heavy metal co-resistance with antibiotics has the potential to amplify antimicrobial resistance genes in the environment, and this could have an impact on clinical settings. This study aimed to investigate the presence of heavy metal co-resistance with antibiotics among plant growth promoting bacterial isolates from the rhizosphere of Nypa fruticans. The heavy metals content of the water habouring the Nypa fruticans including copper(0.07mg/L), chromium (2.3 mg/L), lead (4.22 mg/L), iron (12.4 mg/L), cadmium (0.45 mg/L), nickel (3.12 mg/L), arsenic (0.47 mg/L) and zinc (5.37 mg/L) were above acceptable limits of WHO. A total of 10 bacteria including Bacillus subtilis, Bacillus cereus, Pseudomonas fluorescens, Klebsiella oxytoca, Serratia marcescens, Achromobacter denitrificans, Bulkholderia vietnamiensis and Azospirrilum brasilense, Azobacter vinelandii and Enterobacter aerogenes were isolated and identified to specie level using 16s RNA gene sequences, which showed above 95 % similarity with reference sequences from GenBank. The isolates showed high resistance to lead, chromium and zinc. Most of the isolates were resistant to streptomycin, ciprofloxacin and augmentin. Also, most of the isolates demonstrated positive growth promoting activities of indole acetic acid production, nitrogen fixation, siderophore production and phosphate solubilization. Pot trials on the effect of heavy metal and antibiotic tolerant bacteria on growth of beans (Phaseolus vulgaris l.) in heavy metal polluted soil revealed that beans treated with consortiumof all the isolates recorded high shoot and root length. Hence these isolates can be used for bioremediation of metal polluted site and as well act as plant growth promoting bacterial in agricultural system.

Impact of Seed Priming and Growing Media on Germination and Seedling Growth of Bitter Gourd

Aims: The aim of this study was to determine the suitable growing media and priming treatments for seed germination and seedling growth of bitter gourd (cv. BARI hybrid Korola 2).
 Study Design: The experiment was set up in a completely randomized design (CRD) with sixteen treatments, each containing fifteen seedlings.
 Place and Duration of the Study: The experiment was conducted on Horticulture farm at Sher-e-Bangla Agricultural University; Dhaka, Bangladesh from March to April 2021.
 Methodology: Four seed priming treatments were used in the experiments: T0: Seed soak in distilled water for 12 h (control), T1:Hot water treatment (450C for 5 min), T2: Poly ethylene glycol (PEG) 6000 (5%), T3: Sodium chloride solution (NaCl) (2%) soak for 12h and four growing media viz.,M0: soil + cow dung (1:1), M1: soil + cow dung + vermicompost (1:1:1), M2: soil + cow dung + sawdust (1:1:1), M3: soil + cow dung + cocopeat (1:1:1).
 Results: The maximum germination percentage (100%), highest shoot (21.00 cm) and root length (12.83 cm), seed vigor index (3383.3) was recorded in T2M3 treatment. However, the maximum photosynthetic pigment (30.31 mg/g), relative water content (96.99%) and shoot (3.53g) and root fresh weight (0.47 g) was found in T2M1 treatment.
 Conclusion: It can be concluded that soil + cow dung + cocopeat (1:1:1) with PEG 6000 (5%) is the best treatment for bitter gourd seed germination, while soil + cow dung + vermicompost (1:1:1) with PEG 6000 (5%) is better for vigor and healthy seedlings.

EXAMINATION OF THE QUALITATIVE AND QUANTITATIVE PARAMETERS OF THE WHITE WINE GRAPE VARIETY KIRÁLYLEÁNYKA (FETEASCĂ REGALĂ) IN THE CASE OF DIFFERENT BUD LOADS

Grapes are grown on an area of 8.5 million hectares on Earth. Most of the world's grape production (60%) is located in the regions of Europe. The largest grape and wine-producing countries include France, Italy, and Spain. Viticulture in the Carpathian basin has a history of 2,000 years. The control of the Fetească regală variety which is a traditional Hungarian variety, the control reached the highest sugar content, with an exceptionally high value, and all three loaded treatments were significantly below this. The evolution of the acid content was exactly the opposite, the control reached the lowest value. In terms of survival, all load levels outperformed the control. In conclusion, in the case of Fetească regală, the bud load had both positive and negative effects on the content values, but it had only a positive influence in terms of yield. On the other hand, based on our observation, a high shoot density developed on the high-stressed stems in the plantation, which prevented the phytotechnical operations from being carried out.

Simulation research of fire water cannon nozzle based on fluent

Fire water cannon is the main equipment in fire protection work, which is evolving towards large flow, long distance and high shooting. As an important core component of fire water monitor, the structural design of nozzle plays an important role in jet performance. The Fluent fluid simulation software was used to simulate the internal flow field of the fire nozzle model with different outlet diameters and convergence angles. The average jet velocity and turbulent kinetic energy under different parameters were compared to obtain the optimal size parameters of the fire nozzle. The results show that when the inlet diameter is 100 mm, the inlet pressure is 1.2 MPa, the length of the rectifier section is 95 mm, the outlet diameter is 50 mm, and the convergence angle is 11 °, the jet performance of the fire monitor nozzle is the best. The simulation results can provide reference for the structural design and practical application of fire water monitor nozzle.

Overexpression of gamma-glutamyl cyclotransferase 2;1 (CsGGCT2;1) reduces arsenic toxicity and accumulation in Camelina sativa (L.).

Overexpressing CsGGCT2;1 in Camelina enhances arsenic tolerance, reducing arsenic accumulation by 40-60%. Genetically modified Camelina can potentially thrive on contaminated lands and help safeguard food quality and sustainable food and biofuel production. Environmental arsenic contamination is a serious global issue that adversely affects human health and diminishes the quality of harvested produce. Glutathione (GSH) is known to bind and detoxify arsenic and other toxic metals. A steady level of GSH is maintained within cells via the γ-glutamyl cycle. The γ-glutamyl cyclotransferases (GGCTs) have previously been shown to be involved in GSH degradation and increased tolerance to toxic metals in plants. In this study, we characterized the GGCT2;1 homolog from Camelina sativa for its role in arsenic tolerance and accumulation. Overexpression of CsGGCT2;1 in Camelina under CaMV35S constitutive promoter resulted in strong tolerance to arsenite (AsIII). The overexpression (OE) lines had 2.6-3.5-fold higher shoots and sevenfold to tenfold enhanced root biomass on media supplemented with AsIII, relative to wild-type plants. The CsGGCT2;1 OE lines accumulated 40-60% less arsenic in root and shoot tissues compared to wild-type plants. Further, the OE lines had ~ twofold higher chlorophyll content and 35% lesser levels of malondialdehyde (MDA), an indicator of membrane damage via lipid peroxidation. There was a slight but non-significant increase in 5-oxoproline (5-OP), a product of GSH degradation, in OE lines. However, the transcript levels of Oxoprolinase 1 (OXP1) were upregulated, indicating the accelerated conversion of 5-OP to glutamate, which is further utilized for the resynthesis of GSH to maintain GSH homeostasis. Overall, this research suggests that genetically modified Camelina may have the potential for cultivation on contaminated marginal lands to reduce As accumulation; thereby could help in addressing food safety issues as well as future food and biofuel needs.

Reducing Water Stress, Germination and Shoot Nutrients Accumulation of Avena sativa L. Following Application of Plant Growth-Promoting Bacteria

ABSTRACT Many ecological factors affect the ability of plants to survive and grow. At the same time, drought causes significant limitations to plant growth in arid regions. This study investigated the effects of bio-fertilizers (Azotobacter vinelandii=F1, Pantoea agglomerans+ Pseudomonas putida=F2, F1+F2, control=C) on reducing the effect of water stress factor 100% (FC=field capacity), 70% (0.7FC), and 40% (0.4FC) on germination, growth, and absorption of some nutrients by Avena sativa L. The results indicated that the germination rate was the highest in F1 + 0.7FC and F1 + 0.4FC, respectively and the lowest germination rate was measured in C + 0.7FC. Treatment F1+F2 + 0.4FC compared to C + 0.4FC significantly reduced the germination rate (p < .01). The highest shoot and root lengths were measured in treatment F1+F2 + 0.4FC, and the lowest shoot and root length was measured in treatment F1+F2+FC. In treatment F2 + 0.7FC, shoot and root dry weight increased significantly (p < .01). Treatment F1 + 0.4FC showed the lowest shoot dry weight. In treatment F1+FC, the highest potassium concentration was measured in treatment F2 + 0.7FC, and the highest iron and zinc were measured. The maximum uptake of iron and zinc was measured in F1+FC and F2 + 0.7FC, respectively. Treatment F1+F2 + 0.4FC showed the lowest uptake of iron, zinc, and manganese. Treatment F1+FC caused to increase in nitrogen, phosphorus, and potassium uptake. Generally, the bio-fertilizers had the highest efficiency under 0.7FC and FC conditions. Fertilizers F1 and F2 separately reduced drought’s impact on plant germination. Fertilizers had no noticeable influence on the uptake of nutrients. Bio-fertilizers applied to A. sativa L. could contribute to the restoration and enhancement of rangelands.

The Effects of Arbuscular Mycorrhizal Fungi on Catharanthusroseus (L.) G. Don growth performance in Nizamabad District

In addition to being used in traditional medicine, plants are important suppliers of pharmaceutical drugs. Even though a lot of these compounds can be made in a lab, the process is challenging and produces poor yields that make economic manufacture impracticable.Under open-field circumstances, the important medicinal plant Catharanthusroseus L. (Apocynaceae) was inoculated with AM fungus Glomusaggregatum and Glomusmosseae, and the plant's growth was evaluated.Applying AM to the soil significantly increased plant height over control. In pots inoculated with G. aggregatum rather than G. mosseae or native (mixed inoculum (G. aggregatum, G. mosseae)) inoculum, there is greater shoot and root length. Native (mixed inoculum (G. aggregatum, G. mosseae)) inoculum amendment was inferior to AM amendment with G. aggregatum and G. mosseae. The findings unequivocally demonstrate the benefits of mycorrhizal inoculum on plant development. The two other therapies were less successful than G. aggregatum.The higher shoot and root dry weights following AM inoculations demonstrated increased plant growth. In 120 days, the shoot dry weight of plants injected with G. aggregatum and G. mosseae increased threefold. The dry weight of the roots was doubled.The study demonstrates the capacity of AM fungus G. aggregatumin boosting growth and biomass of Catharanthusroseus L. and indicates that Catharanthusroseus is largely dependent on the mycorrhizal fungi for its survival and growth.

Characterization of Triticum turgidum sspp. durum, turanicum, and polonicum grown in Central Italy in relation to technological and nutritional aspects.

Wheat is a staple food, with the two most common species being Triticum aestivum and Triticum turgidum ssp. durum. Moreover, the latter, T.turgidum, includes other tetraploid subspecies, among which the sspp. turanicum (Khorasan wheat) and polonicum (Polish wheat), whose importance has increased in the last decades, representing alternative crops for marginal areas, in addition to being a source of genetic diversity. In this work, different accessions of these three subspecies of T.turgidum have been grown in 2 years in the same environment and have been characterized for technological properties and factors affecting nutritional quality, such as fiber amount and the content of micro- and macro-nutrients in grains, and for root morphological traits. These analyses allowed the identification, in particular, of a Polish wheat accession showing better technological performances, a higher amount of positive micro- and macro-elements, and a lower amount of toxic cadmium. The modern variety Svevo and the Polish Pol2 showed the lowest and the highest shoot:root ratio, respectively. The high shoot:root ratio in Pol2 was mainly attributable to the decrease in root growth. Although Pol2 had a lower root biomass, its particular root morphology made it more efficient for nutrient uptake, as evident from the greater accumulation of micro- and macro-nutrients. These results underline that it is not possible to draw general conclusions about the difference between primitive and modern wheats, but rather a case-by-case approach should be chosen.

Characterization of genetic variability among sorghum genotypes by morphological descriptors associated with high yield and shoot fly resistance

Characterization of genetic variability among sorghum genotypes by morphological descriptors associated with high yield and shoot fly resistance

English

The canola is an important oilseed crop of the world and Pakistan that grows in a substantial area, but the required quality and yield of canola oil is still not enough to meet the country’s need. Iron (Fe) and Zinc (Zn) are important human nutrients and biofortification of these elements in canola oil is a challenge especially under alkaline calcareous soil conditions owing to less bioavailability of these metal ions in soil. With the same objective, the present investigation was conducted in 2 experiments (Pot and Field trials) with 7 treatments (Control, So-200 kg ha-1, Iron-3 kg ha-1, Zinc-6 kg ha-1, S+Fe, S+Zn and S+Fe+Zn) under pot and filed conditions, separately. The application of S, Fe and Zn resulted in a significant increment in canola crop growth, yield, improved plant physiology and enhanced Fe and Zn uptake and accumulation. The elemental S alone was found to be affecting these properties significantly and combined application with Fe, Zn, and Fe+Zn resulted in further increment in growth, yield, oil percentage and shoot/grain elemental components. For Fe distribution, S application with Fe enhanced its shoot and grains accumulation 16% and 14% compared to alone Fe control under pot settings while 16% and 15% higher shoot and grain Fe was observed under field trial. The shoot and grains’ Zn contents were also found to be significantly improved (10% and 9% higher Zn in shoot and grain of pot-grown canola plants while 19% and 10% increment was observed under filed investigation compared with respective controls).

Sidahermaphrodita establishment on highly weed-infested soil using biodegradable mulch film

The sustainable production of plant biomass for energy and material application within a growing bioeconomy is crucial to overcome the dependence on fossil resources. The perennial industrial crop Sida hermaphrodita L. var. Rusby (Sida) was subject of various investigations as a promising biogenic energy carrier, though its field establishment in the juvenile plant stage is challenging. While suitable chemical measures to suppress weeds in Sida are only scarcely available, the use of herbicides for weed control contradicts the sustainability in bioenergy provision. Therefore, this study aimed for an improved Sida plant establishing method using biodegradable mulch film on highly weed-infested soil. During the year of trial establishment, Sida growth under mulch film treatment was highly improved, resulting in 264% (±49%) higher shoots and 683% (±361%) higher ground cover by Sida compared to the control on bare soil where manual weed treatment was applied only, with weeds significantly reduced in number, size, and ground cover. Employing mulch film for the successful field establishment of Sida proved to be a promising approach as it effectively suppressed weeds despite high weed pressure, resulting in significant growth promotion of Sida.

Potential use of indigenous arbuscular mycorrhizal fungi to improve soil productivity in tailing of tin mining: a greenhouse study scale

Tin mining is as a critical factor destroying ecosystems and challenging for reclamation. Indigenous arbuscular mycorrhizal fungi (AMF) are well-known for assisting plants growing in harsh environments. This study aimed to (1) isolate indigenous AMF; (2) screen AMF for nutrient uptake and plant biomass; (3) investigate the screened AMF in supporting plant growing in tin tailing. Soils were collected from natural forest and post-tin mining in Bangka. Wet sieving was conducted to obtain spore of AMF. Collected AMF were propagated and screened for phosphorus uptake and plant biomass of tested Sorghum bicolor growing in sterilized sand at greenhouse. Eight best-screened AMF was evaluated using Piper nigrum growing in sterilized tin tailing+10% compost at greenhouse. The new leaf number, phosphorus uptake, and flowering emergence were measured. Trap culture obtained 16 Acaulospora sp., 1 Glomus sp., and 1 Scutelospora sp, in post-tin mining, and 9 Acaulospora sp. in natural forest. Screening of AMF resulted in higher shoot P uptake and biomass than controls. Application of screened AMF on tin-talling showed that four AMF had higher new leaf number, phosphorus uptake, and flower emergence of P. nigrum. These results imply that selected indigenous AMF are potential for future land productivity of post-tin mining area.

Plant regeneration from embryogenic callus-derived from immature leaves of Momordica charantia L

Bitter melon (Momordica charantia L.), a widely cultivated food and medicinal plant native to the world's subtropics and tropics, is a Cucurbitaceae rich in carotenoids. However, the low seed germination frequency and progeny variability associated with the production of this plant have a substantial impact on its growth and yield. These constraints affect the availability and exploitation of this crop, especially the fruits, which are rich in secondary metabolites such as β-carotene and α-carotene. In vitro regeneration would help overcome the obstacle linked to the germination of this plant and increase its yield and utilization. A reproducible in vitro organogenesis protocol was established using bitter melon embryogenic callus derived from immature leaf explants of in vivo grown seedlings and in vitro plantlets. Regeneration via callus was conducted on MSB5 media augmented with different plant growth regulator concentrations. The maximum frequency of callus formation (95.09 %) was produced in MSB5 media incorporated with 1.2 mg L−1 NAA augmented with 0.5 mg L−1 TDZ. MSB5 medium with no growth regulators was observed to be the most suitable for the shoot and root formation from the callus, producing a significantly high shoot percentage of 90.91 % and 21.53 shoots per explants, and the highest rooting frequency and root number of 88.92 % and 6.23 roots per explant, respectively, from leaf-derived callus of in vitro plantlets. The elongated plantlets had grown to a significantly higher average height of 12.20 cm on media added with 0.75 mg L−1 GA3. This reproducible method for regenerating bitter melon plantlets could facilitate mass multiplication, conservation, and commercial field production.

Water stress decreases the biocontrol efficacy of a nucleopolyhedrovirus against the fall armyworm on maize

Drought events are expected to limit crop productivity in the context of current climate change. Drought is also likely to affect multitrophic interactions such as those involving plants, phytophagous insects and their natural enemies. We designed a two-phase experiment to test the effect of water availability and fertilizer treatment on the interaction between maize, the fall armyworm and its nucleopolyhedrovirus pathogen. Plants grown in soil with high irrigation and mineral fertilization had the highest shoot and root dry weight. Furthermore, plant nitrogen levels were higher in plants with fertilization and a low irrigation scheme compared to other treatments. Low irrigation of maize plants reduced virus-induced mortality of armyworm larvae. Insects did not feed on plants with high irrigation and without fertilization. We conclude that water stress and plant nutrition can affect virus performance and thereby affect the efficiency of biological control and pest management, especially as water and nutrient limitation will likely increase under climate change.

The Cytokinins BAP and 2-iP Modulate Different Molecular Mechanisms on Shoot Proliferation and Root Development in Lemongrass (Cymbopogon citratus).

The known activities of cytokinins (CKs) are promoting shoot multiplication, root growth inhibition, and delaying senescence. 6-Benzylaminopurine (BAP) has been the most effective CK to induce shoot proliferation in cereal and grasses. Previously, we reported that in lemongrass (Cymbopogon citratus) micropropagation, BAP 10 µM induces high shoot proliferation, while the natural CK 6-(γ,γ-Dimethylallylamino)purine (2-iP) 10 µM shows less pronounced effects and developed rooting. To understand the molecular mechanisms involved, we perform a protein-protein interaction (PPI) network based on the genes of Brachypodium distachyon involved in shoot proliferation/repression, cell cycle, stem cell maintenance, auxin response factors, and CK signaling to analyze the molecular mechanisms in BAP versus 2-iP plants. A different pattern of gene expression was observed between BAP- versus 2-iP-treated plants. In shoots derived from BAP, we found upregulated genes that have already been demonstrated to be involved in de novo shoot proliferation development in several plant species; CK receptors (AHK3, ARR1), stem cell maintenance (STM, REV and CLV3), cell cycle regulation (CDKA-CYCD3 complex), as well as the auxin response factor (ARF5) and CK metabolism (CKX1). In contrast, in the 2-iP culture medium, there was an upregulation of genes involved in shoot repression (BRC1, MAX3), ARR4, a type A-response regulator (RR), and auxin metabolism (SHY2).

Identifying Donors for Anaerobic Germination Tolerance and Direct Seeded Rice Cultivation by Exploring Seed and Seedling Traits

Background: Anaerobic conditions in waterlogged soil affect germination rate significantly reducing rice yields. Under wet direct seeded condition, only limited availability of rice genotypes are suitable for anaerobic germination. So, there is an urgent need to identify rice genotypes for enhanced germination even under anoxic stress. Methods: Experiment was conducted in glass house, Department of Crop Physiology, Tamil Nadu Agricultural University, Coimbatore. In this study, 22 rice germplams with three replications were evaluated for seed and seedling traits underlying anaerobic germination tolerance. Main aim of this study is to explore the starch and sugar relation under anoxic stress and identifying tolerant genotypes for direct seeded rice cultivation. Result: Tolerant genotypes had early emergences, higher shoot and root length along with higher starch degradation and sugar accumulation under waterlogged condition. Cluster analysis revealed that Karuppukavuni, Kalanamak, CBMAS 14065 and Kodavilayan were identified as tolerant genotypes and suitable for wet direct seeded rice cultivation. Finally higher starch degradation coupled with higher accumulation of glucose and fructose were the key traits underlying anaerobic germination tolerance in tolerant genoytpes. Shoot length, root length and sucrose contents had higher genotypic coefficient of variance, phenotypic coefficient of variance coupled with high heritability indicating scope for enhancing anaerobic germination tolerance.

Structural and functional traits underlying the capacity of Calotropis procera to face different stress conditions

Calotropis procera (Aiton) W. T. Aiton, originally native to tropical and sub-tropical regions of northwestern Africa to southwest Asia through the Arabian Peninsula. The present study was engaged to uncover the underlying mechanism (structural and functional) of C. procera sampled from six different ecological regions. The population of normal irrigated agriculture field (IAF) had better growth, high K+ ion content, photosynthetic pigments (chl a chl b, Tchl and caro) and stomatal density. The population of dust and pollution stressed habitat (IWD) exhibited enlarged epidermal cells in stem and leaf, enhanced cortical proportion with largest cells in stem and phloem area in leaf. The population of drought and aridity stressed habitat (ARS) showed increased root cellular area, cortical region thickness and its cell area, and phloem region. The population from salt-affected habitat (SLF) possessed high root and shoot ionic contents (Na+ and Ca2+), total soluble sugars, total antioxidant activity, chlorophyll a/b, widened metaxylem vessels and phloem area in the stem, while intensive sclerification observed in both stem and leaf. The population native to waterlogged and salinity stressed habitat (APC) represented vigorous root growth, total free amino acids, well-developed metaxylem vessels and stomatal area in leaf. The population from drought and salinity-prone habitat (UBL) indicate increased storage of parenchymatous tissue (pith region and its cells area) and epidermal cell area in leaf. It is concluded that C. procera showed much outmost behavior in view of growth, structural and functional attributes in response to prevailing environmental condition.

The Interplay of Sulfur and Selenium Enabling Variations in Micronutrient Accumulation in Red Spinach.

Aside from its importance in human and animal health, low levels of foliar-applied selenate (SeO4) can be advantageous in the presence of sulfur (S), contributing to improved growth, nutrient uptake, and crop quality. A hydroponic experiment in a growth chamber explored the interactive influence of Se and S on micronutrients and several quality indices, such as soluble sugars, organic acids, and total protein concentrations in spinach (Spinacia oleracea L.). Three levels of S (deprivation, adequate, and excessive) with varying quantities of Se (deficient, moderate, and higher) were examined in combination. Under S starvation and along with S nourishment in plant parts, Se treatments were found to cause noticeable variations in plant biomass and the concentrations of the examined elements and other quality parameters. Both Se levels promoted S accumulation in S-treated plants. Although the Se treatment had the opposite effect in shoots, it had a favorable impact on minerals (apart from Mn) in roots grown under S-limiting conditions. The S and Se relationship highlighted beneficial and/or synergistic effects for Mn and Fe in edible spinach portions. Reducing sugars were synergistically boosted by adequate S and moderate Se levels in roots, while in shoots, they were accumulated under moderate-or-higher Se and excessive S. Furthermore, the concentration of the quantified organic acids under S-deficient conditions was aided by various Se levels. In roots, moderate Se under high S application enhanced both malic acid and citric acid, while in the edible parts, higher Se under both adequate and elevated S levels were found to be advantageous in malic acid accumulation. Moreover, by elevating S levels in plant tissues, total protein concentration increased, whereas both moderate and high Se levels (Se1 and Se2) did not alter total protein accumulation in high S-applied roots and shoots. Our findings show that the high S and medium Se dose together benefit nutrient uptake; additionally, their combinations support soluble sugars and organic acids accumulation, contributing ultimately to the nutritional quality of spinach plants. Moreover, consuming 100 g of fresh red spinach shoot enriched with different Se and S levels can contribute to humans' daily micronutrients intake.

Design and Simulation of a Slice-rail and Cylindrical for Multi-Projectile Electromagnetic Launchers

In Electromagnetic launcher (EML) research, beside reasonable L' and high muzzle velocities, there are several key features including multi-turn launching, low field intensity in payload position, high frequency shooting, less unwanted radiation, and so on. Attaining a solution might be feasible by a different structure. In this paper we have studied unequal curved electromagnetic rail launchers (EMRLs) as slice and cylindrical multi-projectile electromagnetic launchers, and the inductance gradient (L') of these structures has been calculated. Making multi-projectile EMRLs using a slice-rail structure is much easier than other plane methods. With a cylindrical multi-projectile EMRL, higher shooting frequency is more feasibly attained and there is no limit on the number of launchers at the same time. High temperature spots which are the result of high velocity and high current density distributions end in intense destructive erosion. Decreasing intense erosion in electromagnetic launcher structures will be more economical and provide greater reliability, therefore resulting in more applications for EMLs especially commercial ones. In parallel electromagnetic launchers, these points and areas are not omissible. In cylindrical EMRLs the problem of high current density distributions and its consequent erosion is significantly decreased because of the uniform distribution of current in its symmetric structure.

Co-Inoculation with Arbuscular Mycorrhizal Fungi and Dark Septate Endophytes under Drought Stress: Synergistic or Competitive Effects on Maize Growth, Photosynthesis, Root Hydraulic Properties and Aquaporins?

Arbuscular mycorrhizal fungi (AMF) and dark septate fungi (DSE) were simultaneously colonized in the root cells of maize. Single AMF and DSE symbiosis have been proven to improve the drought tolerance of maize. However, the effects of both fungi coexisting in maize roots under drought stress are not yet known. In this study, pot experiments of maize seedlings were conducted through four inoculation treatments (single AMF inoculation of Rhizophagus irregularis, single DSE inoculation of Exophiala pisciphila, co-inoculation of AMF + DSE and non-mycorrhizal inoculation) under well-watered (WW) and drought-stressed (DS) conditions. AMF and DSE colonization status, maize physiology and aquaporin gene expression in maize roots were investigated. The objective of this paper was to evaluate whether AMF and DSE had competitive, independent or synergistic effects on regulating the drought tolerance of maize. When maize seedlings of three inoculation treatments were subjected to drought stress, single AMF inoculation had the highest shoot and root dry weight, plant height, root length, osmotic root hydraulic conductivity and hydrostatic root hydraulic conductivity in maize seedlings. However, co-inoculation of AMF + DSE induced the highest stomatal conductance in maize leaves and the lowest H2O2 and O2•- concentration, membrane electrolyte leakage, intercellular CO2 concentration and gene expression level of ZmPIP1;1, ZmPIP1;2, ZmPIP2;1, ZmPIP2;5 and ZmPIP2;6. In addition, co-inoculation of AMF + DSE also obviously down-regulated the GintAQPF1 and GintAQPF2 expression in R. irregularis compared with single AMF inoculation treatment. Under DS stress, there were competitive relationships between AMF and DSE with regard to regulating mycorrhizal colonization, maize growth, root hydraulic conductivity and the gene expression of aquaporins in R. irregularis, but there were synergistic relationships with regard to regulating membrane electrolyte leakage, oxidative damage, photosynthesis and the aquaporin gene expression of maize seedlings. The obtained results improve our knowledge about how the mechanisms of AMF and DSE coexist, promoting the drought tolerance of host plants.