Increased Shoot Dry Weight Research Articles

Assessing anti-transpiration potential of beeswax waste on Calendula officinalis under drought stress conditions

Beeswax waste, as a novel biostimulant, may be involved in anti-transpiration process in plants exposed to drought stress. Therefore, the aim of this study was to investigate the anti-transpiration effect of beeswax waste in comparison with chitosan, a known anti-transpiration substance. The treatments consisted of two drought stress conditions [no stress, 90% field capacity; and stress, 40% field capacity (FC)] together with four exogenous foliar applications [control (water), beeswax waste extract (BWE), chitosan, and BWE +chitosan]. Plants subjected to irrigation with 40% FC displayed a significant reduction in plant yield and physiological traits. In drought stress, foliar application with BWE and BWE + chitosan increased shoot dry weight, flower number and weight, net photosynthesis (Pn), essential oil percentage and yield, and decreased membrane permeability compared with water and chitosan spraying. Under drought stress, foliar treatment with BWE and chitosan decreased stomatal conductivity by about 8% and 31%, and transpiration (Tr) by 7% and 22%, respectively compared with water spraying. Under these conditions, the leaves sprayed with BWE and BWE + chitosan exhibited a lower temperature compared with water and chitosan treatments. Furthermore, foliar spraying with BWE + chitosan, BWE and chitosan increased the water use efficiency (WUE) by 104%, 92% and 56%, respectively, compared to control. Foliar application with BWE, chitosan and BWE + chitosan improved ascorbate peroxidase (APX) and catalase (CAT) activity and osmoregulation parameters (increased proline, proteins and soluble sugars) as plant adaptive mechanisms to drought. In conclusion, BWE can mitigate the drought stress similarly to chitosan, a better known anti-transpiration agent.

Symbiotic effectiveness of Bradyrhizobium strains on soybean growth and productivity in Northern Mozambique

Inoculation of soybean [Glycine max(L.) Merr.] with rhizobia strains is a low-cost investment which can increase yields of smallholder farmers in Mozambique. The performance of fourBradyrhizobiumstrains was evaluated to identify the best strain to inoculate soybean grown in different agro-ecologies. Field experiments were conducted in three ecological zones in 2018 and 2019 using soybean variety Zamboane inoculated withBradyrhizobium diazoefficiensstrain USDA 110,B. japonicumstrains USDA 136, USDA 442 and WB74, and a non-inoculated control in a randomized complete block design with four replications. Indigenous rhizobia populations at the sites ranged from 9.0 x 101to 2.2 x 103cells g−1soil. All four strains increased nodulation, but USDA 110 was superior at two sites with low native rhizobia population, whereas USDA 442 and WB74 were the best at the site with relatively high native rhizobia population. On an average, the strains doubled the number of nodules and increased the dry weight up to 5.8-fold. Inoculation increased shoot dry weight and N content at podding, plant biomass, and number of pods plant−1across sites but the effects of the strains on seeds per pod, and 100-seed weight were inconsistent. Shoot N content did not differ among inoculant strains and ranged from 15.70 g kg−1in the control to 38.53 g kg−1across inoculation. All four strains increased soybean grain yield across sites in 2018 but USDA 110 outperformed the other strains and was also the best at one of the two sites in 2019. Grain yield responses associated with USDA 110 ranged from 552 kg ha−1(56%) to 1,255 kg ha−1(76%). Positive correlations between nodule dry weight plant−1and seed yield, and number of pods plant−1and grain yield were observed. The gross margin ranged from $343.50–$606.80 ha−1for the control, but it increased to $688.34–$789.36 when inoculants were applied. On an average, inoculation increased gross margin by $182.57-$395.35 ha−1over that of non-inoculated control in 2018 but drought stress in 2019 reduced the benefit. The results demonstrate that USDA 110 was the best inoculant strain and has the potential of increasing smallholder productivity and net returns.

Fertilizer type and irrigation frequency affect plant growth, yield, and gas exchange of containerized strawberry cultivars

Small-scale strawberry production in southeastern states requires cultivars adaptive to local climates and with season extension potentials. This study investigated plant growth, yield, gas exchange, and fruit quality of ten strawberry (<italic>Fragaria ×ananassa</italic> Duch.) cultivars affected by fertilizer type and irrigation frequency in a containerized production system in 2018. Bare root liners of seven June-bearing and three day-neutral cultivars were grown in 2-gallon containers , fertilized with a conventional fertilizer or an organic fertilizer at comparable rates, and irrigated once or twice daily with the same total irrigation volume<bold>.</bold> Strawberry cultivars varied in vegetative growth (including plant growth index (PGI), leaf SPAD, number of crowns, visual score, and root dry weight) and fruiting characteristics (including first harvest date, yield, number of fruit, berry size, fruit soluble solids content, and firmness). Day-neutral cultivars ‘Evie 2’ and ‘Seascape’ produced the highest total yields and late-season yield in June. The conventional fertilizer resulted in higher PGI, leaf SPAD, plant visual score, fruit yield in May, daily water use, and net photosynthetic rate than the organic fertilizer. Two irrigations per day increased substrate moisture compared with one irrigation per day, and increased shoot dry weight with the conventional fertilizer application. Irrigation frequency did not affect PGI, leaf SPAD, gas exchange, fruit yield, or quality in tested strawberry cultivars.

The Effect of the Stress-Signalling Mediator Triacontanol on Biochemical and Physiological Modifications in Dracocephalum forrestii Culture

Triacontanol (TRIA) has been reported to influence signal transduction in the crosstalk triggered by various stress factors. As a signal player, it is also known to affect many physiological processes, including enhancing the biosynthesis of secondary metabolites. Such knowledge can be used to direct or boost the production of bioactive secondary compounds without stress induction. Therefore, the aim of this study is to evaluate the use of TRIA as a factor stimulating the growth and production of bioactive compounds in the shoot culture of Dracocephalum forrestii. TRIA was applied at three concentrations (2.5, 5, and 10 µM), alone or in combination with phytohormones (6-benzylaminopurine and indole-3-acetic acid). After five weeks, growth and physiochemical parameters (chlorophyll content, antioxidant enzyme activity, and phenolic acid level) were determined. The results indicate that TRIA application significantly increased shoot dry weight, chlorophyll content, antioxidant enzyme activities (superoxide dismutase, peroxidase, and catalase), and total polyphenol level; it also influenced the multiplication ratio in combination with growth regulators. The greatest antioxidant enzyme activity was observed for 5 µM TRIA in hormone-free medium, while the most significant secondary metabolite production was obtained for phytohormone-containing medium supplemented with 10 µM TRIA: total phenolic acid content (19.4 mg/g dry weight) was twice that of the control. Hence, the TRIA application appears to be a valuable biotechnology technique for modifying plant metabolite production.

Ameliorative effects of seed treated with phytohormones on seedling growth, soluble protein content and antioxidant enzymes of hargel (Solenostemma argel Hayne) seedlings under salt stress

Salinity stress profoundly affects crop plants’ morphological structures and physiological processes, decreasing plant growth and development. The application of phytohormones has been proved an efficient way to alleviate salinity stress. This study was done to evaluate the effects of exogenous application of gibberellic acid (GA3; 0.288 mM), salicylic acid (SA; 0.362 mM), indole acetic acid (IAA; 0.285 mM) and control (0 mM) on seedling growth and physiological parameters of hargel (Solenostemma argel Hayne) seedlings under different salinity levels (0, 50 and 100 mM NaCl). Significant decreases due to salinity stress were observed in all the seedling growth parameters shoot and root length, shoot fresh weight, shoot dry weight, root fresh weight, root dry weight, chlorophyll a and b content, and antioxidant enzymes activities such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX). In contrast, soluble protein and carotenoid content increased with increasing salinity. At high salinity level, GA3 increased carotenoid content and APX activity by 56.4% and 53.4%, respectively, while SA increased shoot dry weight, SOD, POD and soluble protein by 1.3-fold, 1.3-fold, 1.95-fold and 93.2%, compared with the control, IAA increased root length and fresh root weight at the same salinity level by 1.58-fold and 2-fold, respectively. In conclusion, seed priming with an appropriate dosage of exogenous hormones successfully mitigates the adverse effects of NaCl by increasing photosynthetic pigment, antioxidant enzyme activity and seedling growth parameters. Furthermore, SA exhibited the best mitigating effects compared to IAA and GA3.

Modeling root loss reveals impacts on nutrient uptake and crop development.

Despite the widespread prevalence of root loss in plants, its effects on crop productivity are not fully understood. While root loss reduces the capacity of plants to take up water and nutrients from the soil, it may provide benefits by decreasing the resources required to maintain the root system. Here, we simulated a range of root phenotypes in different soils and root loss scenarios for barley (Hordeum vulgare), common bean (Phaseolus vulgaris), and maize (Zea mays) using and extending the open-source, functional-structural root/soil simulation model OpenSimRoot. The model enabled us to quantify the impact of root loss on shoot dry weight in these scenarios and identify in which scenarios root loss is beneficial, detrimental, or has no effect. The simulations showed that root loss is detrimental for phosphorus uptake in all tested scenarios, whereas nitrogen uptake was relatively insensitive to root loss unless main root axes were lost. Loss of axial roots reduced shoot dry weight for all phenotypes in all species and soils, whereas lateral root loss had a smaller impact. In barley and maize plants with high lateral branching density that were not phosphorus-stressed, loss of lateral roots increased shoot dry weight. The fact that shoot dry weight increased due to root loss in these scenarios indicates that plants overproduce roots for some environments, such as those found in high-input agriculture. We conclude that a better understanding of the effects of root loss on plant development is an essential part of optimizing root system phenotypes for maximizing yield.

Proteome and physiological analyses reveal tobacco (Nicotiana tabacum) peroxidase 7 (POD 7) functions in responses to copper stress

Copper is a micronutrient essential for plant growth and development. However, Cu is also a heavy metal element that has deleterious impacts on plants when excessively accumulated in the environment. To understand the molecular mechanism underlying tobacco in response to Cu stress, iTRAQ based technology was used to identify differentially expressed proteins (DEPs) and important metabolic pathways in tobacco plants treated with excessive CuSO4. The results showed that 180 DEPs were detected between the treatment and control, among which 78 were upregulated and 102 were downregulated. These DEPs can be functionally divided into 65 categories and are closely related to metabolic pathways, carbon metabolism, secondary metabolite biosynthesis, biosynthesis of antibiotics, glyoxylate and dicarboxylate metabolism, and glycolysis/gluconeogenesis. Peroxidase7 was significantly upregulated and was selected and overexpressed in tobacco. Then, positive transgenic lines and wild type plants were exposed to a Cu stress environment. The results showed that Peroxidase7 transgenic tobacco plants exhibited enhanced Cu stress resistance with decreased malondialdehyde and Cu contents, and increased shoot dry weight, root length, secondary root number, SOD, POD and CAT activity. The present study suggests that the ROS scavenging mechanism is essential for tobacco plants in response to Cu stress and that Peroxidase7 functions in tobacco plant resistance to excessive Cu environment.

Arbuscular Mycorrhizal Fungi Mediated Enhanced Biomass, Root Morphological Traits and Nutrient Uptake under Drought Stress: A Meta-Analysis.

Drought stress remains the major constraint in affecting crop productivity in several arid and semi-arid areas highlighting climate change perspectives. Arbuscular mycorrhizal fungi (AMF) belong to a versatile class of plant–fungal symbiotic associations establishing drought stress alleviation. Nevertheless, the mechanistic mode of sustainable agriculture necessitates rigorous assessment for authentic and reproducible plant growth parameters. Understanding the plant growth promotion, root morphological changes, and nutrient uptake response in AMF-inoculated plants to drought is very important for sustainable agriculture. Therefore, conducted a meta-analysis of published research articles for determining the efficacy of AMF in alleviating drought stress. Overall analysis showed that AM inoculated plants had 49% higher plant growth promotion than the non-mycorrhizal plants under drought stress. Biomass analysis depicted the root dry weight increase by 49%, shoot dry weight increase by 54%, and total dry weight increase by 58% indicating plant biomass traits augmentation. Root morphological traits analysis corresponded to increased root length (37%), root surface (31%), and root volume (65%). Notably, nutrient uptake assessment showed variable increases in uptake patterns such as P uptake by 86%, N uptake by 35%, and K uptake by 46%. Furthermore, the prominent efficacy of AMF was significantly larger under drought for P uptake (p < 0.001) and root volume (p < 0.001) indicating the linear relationship between root length and P uptake. Thus, the present meta-analysis confirms that drought stress alleviation emancipated by AMF is mediated by root traits modification and phosphorous acquisition efficacy. Hence, meta-analyses along with experimental validations with field trial evaluations will certainly provide the AMF research for escalated applications for better plant productivity, stress alleviation, and sustainable agriculture.

The effect of some soil conditioners on the yield and quality of sweet pepper grown under saline soil conditions using two sources of organic nitrogen fertilizers

Because of increased population worldwide in general and Egypt in particular , this may lead to a problem in the lack of food and fertile land area therefore, we resort to the expansion of the cultivation of salt soil. For that this experiment was carried out during two summer seasons of 2020 and 2021 at the Experimental Farm of El-Kassasein, Hort. Res. Station, Ismailia Governorate, Egypt, to study the effect of organic nitrogen sources (poultry manure and botanical compost ) and some soil conditioners ( magnetic iron at 25 and 50 kg /fed. and humic acid at 2 and 4 kg /fed.) on growth, yield and fruit quality of sweet pepper cv Top Star under sandy soil conditions. Fertilizing sweet pepper plants grown in sandy soil with 180 kg N as organic nitrogen in the form of poultry manure ( 5.521 ton /fed.) increased plant growth, N, P and K uptake by shoots, yield and its components , nitrogen use efficiency, dry matter, total soluble solids and Vit. C and decreased nitrate content in fruits compared to fertilizing with 180 kg N as organic nitrogen in the form of botanical compost (9.890 ton /fed.). Adding magnetic iron and humic acid as salt soil conditioners at different rates to sandy soil increased plant growth, N, P and K uptake by shoots, yield and its components, fruit traits, dry matter, total soluble solids and Vit. C and decreased nitrate content in fruits compared to control (without soil conditioners). Fertilizing with poultry manure at 5.521 ton /fed. and adding magnetic iron at 50 kg /fed. increased shoot dry weight, N, P and K contents and uptake by shoots, number of fruits/ plant, average fruit weight, yield / plant , total yield /fed. nitrogen use efficiency, dry matter and total soluble solids in fruits, whereas poultry manure at 5.521 ton/fed. and humic acid at 4 kg /fed. increased Vit. C and decreased nitrate contents in fruits.

The Interaction Between Nitrogen Supply and Light Quality Modulates Plant Growth and Resource Allocation

Nitrogen availability and light quality affect plant resource allocation, but their interaction is poorly understood. Herein, we analyzed the growth and allocation of dry matter and nitrogen using lettuce (Lactuca sativa L.) as a plant model in a factorial experiment combining three light regimes (100% red light, R; 50% red light + 50% blue light, RB; 100% blue light, B) and two nitrogen rates (low, 0.1 mM N; high, 10 mM N). Red light increased shoot dry weight in relation to both B and RB irrespective of nitrogen supply. Blue light favored root growth under low nitrogen. Allometric analysis showed lower allocation to leaf in response to blue light under low nitrogen and similar leaf allocation under high nitrogen. A difference in allometric slopes between low nitrogen and high nitrogen in treatments with blue light reflected a strong interaction effect on root-to-shoot biomass allocation. Shoot nitrate concentration increased with light exposure up to 14 h in both nitrogen treatments, was higher under blue light with high nitrogen, and varied little with light quality under low nitrogen. Shoot nitrogen concentration, nitrogen nutrition index, and shoot NR activity increased in response to blue light. We conclude that the interaction between blue light and nitrogen supply modulates dry mass and nitrogen allocation between the shoot and root.

Responses of butter leaf lettuce to mixed red and blue light with extended light/dark cycle period

To investigate the effects of extended light/dark (L/D) cycle period (relative to the diurnal L/D cycle) on lettuce and explore potential advantages of abnormal L/D cycles, butter leaf lettuce were grown in a plant factory with artificial light (PFAL) and exposed to mixed red (R) and blue (B) LED light with different L/D cycles that were respectively 16 h light/8 h dark (L16/D8, as control), L24/D12, L48/D24, L96/D48 and L120/D60. The results showed that, all the abnormal L/D cycles increased shoot dry weight (DW) of lettuce (by 34–83%) compared with the control, and lettuce DW increased with the L/D cycle period prolonged. The contents of soluble sugar and crude fiber in lettuce showed an overall upward trend with the length of L/D cycle extended, and the highest vitamin C content as well as low nitrate content were both detected in lettuce treated with L120/D60. The light use efficiency (LUE) and electric use efficiency (EUE) of lettuce reached the maximum (respectively 5.37% and 1.76%) under L120/D60 treatment and so were DW, Assimilation rate (A), RC/CS, ABS/CS, TRo/CS and DIo/CS, indicating that longer L/D cycle period was beneficial for the assimilation efficiency and dry matter accumulation in lettuce leaves. The highest shoot fresh weight (FW) and nitrate content detected in lettuce subjected to L24/D12 may be related to the vigorous growth of root, specific L/D cycle seemed to strengthen root growth and water absorption of lettuce. The openness level of RC in PSII (Ψo), ETo/CS, and PIabs were all the highest in lettuce treated with L24/D12, implying that slightly extending the L/D cycle period might promote the energy flowing to the final electron transfer chain. In general, irradiation modes with extended L/D cycle period had the potential to improve energy use efficiency and biomass of lettuce in PFAL. No obvious stress or injury was detected in lettuce subjected to prolonged L/D cycles in terms of plant growth and production. From the perspective of shoot FW, the optimal treatment in this study was L24/D12, while L120/D60 was the recommended treatment as regards of the energy use efficiency and nutritional quality.

Psychrotrophic plant beneficial bacteria from the glacial ecosystem of Sikkim Himalaya: Genomic evidence for the cold adaptation and plant growth promotion

Commercial biofertilizers tend to be ineffective in cold mountainous regions due to reduced metabolic activity of the microbial inoculants under low temperatures. Cold-adapted glacier bacteria with plant growth-promoting (PGP) properties may prove significant in developing cold-active biofertilizers for improving mountain agriculture. With this perspective, the cultivable bacterial diversity was documented from the East Rathong glacier ecosystem lying above 3900 masl of Sikkim Himalaya. A total of 120 bacterial isolates affiliated to Gammaproteobacteria (53.33%), Bacteroidetes (16.66%), Actinobacteria (15.83%), Betaproteobacteria (6.66%), Alphaproteobacteria (4.16%), and Firmicutes (3.33%) were recovered. Fifty-two isolates showed many in vitro PGP activities of phosphate solubilization (9–100 µg/mL), siderophore production (0.3–100 psu) and phytohormone indole acetic acid production (0.3–139 µg/mL) at 10 °C. Plant-based bioassays revealed an enhancement of shoot length by 21%, 22%, and 13% in ERGS5:01, ERMR1:04, and ERMR1:05, and root length by 14%, 17%, 11%, and 22% in ERGS4:06, ERGS5:01, ERMR1:04, and ERMR1:05 treated seeds respectively. An increased shoot dry weight of 4–29% in ERMR1:05 and ERMR1:04, and root dry weight of 42–98% was found in all the treatments. Genome analysis of four bacteria from diverse genera predicted many genes involved in the bacterial PGP activity. Comparative genome study highlighted the presence of PGP-associated unique genes for glucose dehydrogenase, siderophore receptor, tryptophan synthase, phosphate metabolism (phoH, P, Q, R, U), nitrate and nitrite reductase, TonB-dependent receptor, spermidine/putrescine ABC transporter etc. in the representative bacteria. The expression levels of seven cold stress-responsive genes in the cold-adapted bacterium ERGS4:06 using real-time quantitative PCR (RT-qPCR) showed an upregulation of all these genes by 6–17% at 10 °C, and by 3–33% during cold-shock, which indicates the cold adaptation strategy of the bacterium. Overall, this study signifies the psychrotrophic bacterial diversity from an extreme glacier environment as a potential tool for improving plant growth under cold environmental stress.

Melatonin application on phytochemical compositions of Agastache foeniculum under water-deficit stress

Background: Agastache foeniculum is one of the perennial aromatic plants of the Lamiaceae family. The essential oil (EO) of this plant has potent antibacterial and antifungal properties, and hence it is extensively used in the pharmaceutical and food industries. Water-deficit stress occurring at any plant growth stage changes the morphological, phytochemical, and physiological processes. Melatonin is considered as a new kind of plant growth regulator which increases plant tolerance to environmental stresses.&#x0D; Hypotheses: The response to water deficit in A. foeniculum is Mel-dependent and affects their physiological and phytochemical characteristics&#x0D; Studied species: Agastache foeniculum &#x0D; Study site and dates: Tabriz, Iran, 2019.&#x0D; Methods: For this purpose, plants were subjected to water-deficit stress, which was followed by foliar application of melatonin as biostimulants on dry matter and secondary metabolites of A. foeniculum .&#x0D; Results: Results indicated that water-deficit stress (at 60 % of Field capacity) increased shoot dry weight, total phenol, anthocyanins and flavonoids content as well as EO content. Application of various melatonin concentrations improved the content of the mentioned traits. According to GC-MS analysis, ten chemical compounds were recognized in the EO composition of A. foeniculum . The most important EO compound (%) in the studied treatments was methyl chavicol, under severe water-deficit stress conditions with Mel at concentration of 100 μM.&#x0D; Conclusions: The results indicated that the application of Mel (at 100 µM) as a bio-inducer can alleviate the detrimental effects of water-deficit stress (at 60 and 30 % field capacity) and improve the quality of EO.

Interactive effect of glycine, alanine, and calcium nitrate Ca(NO3)2 on wheat (Triticum aestivum L.) under lead (Pb) stress.

Aim of this study was to evaluate the interactive effects of glycine, alanine, calcium nitrate [Ca(NO3)2], and their mixture on the growth of two wheat (Triticum aestivum L.) varieties, i.e., var. Punjab-2011 and var. Anaj-2017 under lead [0.5mM Pb(NO3)2] stress. A pot experiment was conducted for this purpose. Pre-sowing seed treatment with 1mM glycine, alanine, and calcium nitrate [Ca(NO3)2] was applied under two levels of lead nitrate [Pb(NO3)2] stress, i.e., control and 0.5mM Pb(NO3)2. Lead (0.5mM) stress significantly decreased root and shoot lengths, fresh and dry weights of root and shoot, and chlorophyll contents, while it increased activities of antioxidant enzymes such as catalase (CAT), ascorbate peroxidase (APX), guaiacol peroxidase (GPX), and peroxidase (POD) in both wheat varieties. Lead (0.5mM) stress increased the accumulation of free proline, glycinebetaine, total free amino acids, and total soluble protein contents. Although var. Punjab-2011 was higher in root fresh and dry weights, shoot length, and total leaf area per plant, however, var. Anaj-2017 showed less reduction in shoot dry weight, root fresh weight, and shoot length under lead stress. Under lead stress, Punjab-2011 was higher in grain yield and number of grain plant-1, chlorophyll a contents, membrane permeability (%), POD activity, total free amino acids, and glycinebetaine (GB) contents as compared to Anaj-2017. Pre-sowing seed treatments with glycine, alanine, calcium nitrate, and their mixture (1mM of each) increased shoot dry weight, number of grains per plants, 100-grain weight, number of spikes, and chlorophyll a contents under normal and lead-stressed conditions. Wheat var. Anaj-2017 showed higher growth and yield attributes as compared to var. Punjab-2011. Results of the current study have shown that pre-sowing seed treatments with glycine, alanine, calcium nitrate, and their mixture (1mM of each) can overcome the harmful effects of lead (Pb) stress in wheat plants.

Native Rhizospheric and Endophytic Fungi as Sustainable Sources of Plant Growth Promoting Traits to Improve Wheat Growth under Low Nitrogen Input.

Wheat crops require effective nitrogen fertilization to produce high yields. Only half of chemical N2 fertilizers are absorbed into plants while the rest remains in the soil, causing environmental problems. Fungi could maximize nitrogen absorption, and from an environmental and biodiversity point of view, there is an urgent necessity for bioprospecting native fungi associated with wild plants growing in harsh environments, e.g., St. Katherine Protectorate (SKP) in the arid Sinai. Recovered taxa, either endophytic and/or rhizospheric, were screened for their plant growth-promoting (PGP) traits. Eighteen fungal isolates (15 rhizospheric and 3 endophytic) belonging to anamorphic ascomycetes were recovered from 9 different wild plants, and their PGP traits (indole-3-acetic acid [IAA] production, phosphate solubilization, siderophore production, and hydrolytic enzyme production) were measured. Rhizospheric isolate NGB-WS14 (Chaetosphaeronema achilleae) produced high levels of IAA (119.1 μg mL−1) in the presence of tryptophan, while NGB-WS 8 (Acrophialophora levis) produced high IAA levels (42.4 μg mL−1) in the absence of tryptophan. The highest phosphate-solubilizing activity (181.9 μg mL−1) was recorded by NGB-WFS2 (Penicillium chrysogenum). Endophytic isolate NGB-WFE16 (Fusarium petersiae) exhibited a high percentage level of Siderophore Unit (96.5% SU). All isolates showed variability in the secretion of extracellular hydrolytic enzymes. Remarkably, all isolates had antagonistic activity (55.6% to 87.3% suppression of pathogen growth) against the pathogenic taxon Alternaria alternata (SCUF00001378) in the dual-assay results. Out of the 18 isolates, 4 rhizospheric and 1 endophytic isolate showed significant increases in shoot dry weight and shoot nitrogen and chlorophyll content of wheat plants subjected to low inputs of chemical nitrogen (N) fertilizers (50% reduction) compared with the non-inoculated control in a pot experiment. Potent taxa were subjected to sequencing for molecular confirmation of phenotypic identification. The retrieved ITS sequences in this study have been deposited in GenBank under accession numbers from LC642736 to LC642740. This study considered the first report of endophytic fungi of Cheilanthes vellea, a wild plant with PGPF which improves wheat growth. These results recommend using PGPF as inoculants to alleviate low nitrogen fertilization.

Effects of Boron Application and Gamma Ray Irradiation On Yield of Sugar Beet (Beta Vulgaris L.) Grown in Sandy Soil

Effects of boron as an essential nutrient for sugar beet along with gamma irradiation was traced under field conditions. Data demonstrated that the fresh and dry root yields of sugar beet significantly increased with the increase either gamma dose or boron levels comparing to the non-irradiated and born-untreated plants. It seems that root dry weight tended to increase gradually with increasing gamma dose 0 to 100 Gy, then tended to decrease with 200 Gy dose but it still increased with gradual increases of boron levels. In this regard, the best value of root dry weight was achieved with 100 Gy dose interacted with 2.40 kg/ ha of boron addition. On the other hand, plants exposed to 50 Gy and treated with 2.40 kg/ ha reflected the highest shoot dry matter yield compared to other treatments. Relatively, this treatment increased shoot dry weight by about one fold, two folds and near to two folds for the same sequence. Behavior of NPK uptake by shoots has the same trend. Plants irradiated with 100 Gy together with 2.40 kg boric acid ha-1 yielded the highest total soluble solids (TSS%) and produced the best per cent of sucrose. Bangladesh J. Bot. 50(4): 1041-1049, 2021 (December)

Influence of Spatial Planting Arrangement of Winter Rye Cover Crop on Corn Seedling Disease and Corn Productivity.

Despite numerous environmental benefits associated with cover crop (CC) use, some farmers are reluctant to include CCs in their production systems because of reported yield declines in corn. There are numerous potential reasons for this yield decline, including seedling disease. A winter rye CC can serve as a "green bridge" for corn seedling pathogens. We hypothesized that proximity of corn seedling roots to decaying rye CC roots contributes to corn seeding disease. An experimental field plot and an on-farm study were conducted over 2 years to evaluate growth, development, and disease severity of corn seedlings planted at various distances from decaying winter rye CC plants. The experimental field plot study was conducted in a no-till corn-soybean rotation with five replications of a winter rye CC treatment seeded as (i) no-CC control, (ii) broadcast, (iii) 19-cm drilled rows, and (iv) 76-cm drilled rows. The on-farm study was no-till corn-soybean rotation with four replications of a winter rye CC seeded as 38-cm drilled rows, 76-cm drilled rows, and no-CC control. The corn was planted on 76-cm rows shortly after rye was terminated. With multiple seeding arrangements of winter rye, corn was planted at different distances from winter rye. Corn radicle root rot severity and incidence, shoot height, shoot dry weight, corn height and chlorophyll at VT (tasseling), ear parameters, and yield were collected. Soil samples were taken in the corn row and the interrow at winter rye termination, corn planting, and corn growth stage V3 (three leaves with fully developed collars) to estimate the abundance of Pythium clade B members present in soil samples. Our results showed that increased distance between winter rye residue and corn reduced seedling disease and Pythium clade B populations in the radicles and soil and increased shoot dry weight, leaf chlorophyll, plant height, and yield. This suggests that physically distancing the corn crop from the winter rye CC is one way to reduce the negative effects of a winter rye CC on corn.

Melatonin improves the photosynthesis in Dracocephalum kotschyi under salinity stress in a Ca2+/CaM-dependent manner.

This study investigated: (1) the effects of various concentrations of melatonin (MT) and Ca2+; and (2) the impact of crosstalk between these signal molecules on photosynthesis and salt tolerance of Dracocephalum kotschyi Boiss. Results indicated that 5mM CaCl2, as well as 100μM MT were the best concentrations for increasing shoot dry weight, leaf area, SPAD index, maximum quantum efficiency of photosystem II (Fv/Fm), and decreasing malondialdehyde content under salinity stress. The impact of MT on growth and photosynthesis was closely linked to its effect on enhancing antioxidant enzyme activities in leaves. Application of p-chlorophenylalanine, as an inhibitor of MT biosynthesis, negated the impacts of MT on the aforementioned attributes. Salinity and MT boosted cytosolic Ca2+ concentration. Exogenous MT, as well as Ca2+, enhanced tolerance index, membrane stability, leaf area, the content of chlorophyll (Chl) a, Chl b, and carotenoids (Car), Fv/Fm, and stomatal conductance under salinity stress. These impacts of MT were eliminated by applying a calmodulin antagonist, a Ca2+ chelator and a Ca2+ channel blocker. These novel findings indicate that the MT-induced effects on photosynthetic parameters and salt-evoked oxidative stress were mediated through calcium/calmodulin (Ca2+/CaM) signalling.

Effects of Potassium Availability on Growth and Development of Barley Cultivars

Potassium deficiency is one of the major issues affecting crop production around the globe. Giving the high cost of potassium fertilizers and environmental concerns related to inappropriate fertilization practices, developing more potassium use efficient (KUE) varieties is critical for sustainable food production in agricultural systems. In this study, we analysed the impact of potassium availability on agronomical attributes of thirty barley genotypes grown at four different levels of potassium (0.002 mM, 0.02 mM, 2 mM, 20 mM) under glasshouse conditions. The results showed that the availability of potassium in the soil had a major effect on yield components i.e., spike number, grain number and grain weight. Furthermore, grain weight showed a strong correlation with grain number and spike number at all levels of potassium supply. Although an increase in potassium supply led to an increase in plant height in all genotypes, the correlation with grain weight was very weak at all levels. Potassium supplementation caused an increase in shoot dry weight, which also showed a weak correlation with grain weight at the 0.002 mM potassium supply level. The genotypes Gebeina, Skiff, YF374, Flagship and YF374 were highly efficient in performing at suboptimal K supply levels and, thus, can be recommended to be grown in K-impoverished soils. We also suggest that grain and spike numbers could be used as proxies for KUE studies, to construct DH lines and identify QTL to improve low potassium tolerance and KUE in barley.

Optimum growth and quality of the edible ice plant under saline conditions.

Ice plant is a halophyte, known for its antioxidant activity and for being a highly functional food. It is capable of increasing its contents of health-promoting compounds when subjected to certain stresses such as salinity. The objective of this work was to determine the plant's best growing conditions to achieve both an optimal production of bioactive metabolites and high crop yield. Mesembryanthemum crystallinum were grown under semi-controlled conditions and four saline treatments were applied at: 0, 100, 200 and 300 mmol L-1 sodium chloride (NaCl), respectively. The 100 mmol L-1 NaCl treatment induced a slight increase in shoot dry weight (DW) and enhanced the leaf area. At higher salinity levels, however, the shoot biomass decreased. The concentration of starch and total proteins declined as the concentration of salt increased, while the total soluble sugars (TSS) content was lower in 100 and 300 mmol L-1 NaCl treatments. Proline increased in conditions over 100 mmol L-1 NaCl. Furthermore, plants grown with 300 mmol L-1 of NaCl presented the highest values of glutathione, ascorbic acid and vitamin C. Antioxidant enzymes activity and total phenolics increased with the severity of the salinity. Ice plant accumulates high levels of health-promoting compounds when grown with 300 mmol L-1 NaCl. A high concentration of beneficial compounds, however, is detrimental to the plant's growth. Moreover, 100 mmol L-1 NaCl treatment not only improved the concentration of bioactive and antioxidant compounds but also preserved the crop yield. It could thus be interesting to promote the cultivation of this high nutritional value plant in environments of moderate salinity. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.