Faba Bean Plants Research Articles

The possible cytogenecity and mutagenicity effects of Allium sativum as a natural fungi/ pesticide on faba bean plant

Allium sativum (garlic) is one of the most famous plant rich in Sulphur products which are so beneficial in bio-gardening and agriculture if applied in right ratios as natural fertilizer to the soil poor in organic matter (under 2%) or applied as natural fungicide &pesticide.

Bio-Remediation of Pb-contaminated Soil Cultivated With Faba Bean Via Application of Rhizobacteria Bacillus amyloliquefaciens subsp. plantarum UCMB 5033

Bio-remediation of Faba bean (Vicia faba cv. luz deotono) plants growing under lead (Pb) contaminated soil using the bacteria strain Bacillus amyloliquefaciens subsp. plantarum UCMB 5033 was tested under three Pb concentrations (2000mg/L 0.5%, 2500mg/L 1.0%, 3000mg/L 5%). Growth parameters (plant height, plant fresh weight, and plant dry weight of the Pb-treated bacteria inoculated Faba bean plants showed significant increases compared to the Pb-treated non-inoculated Faba bean plants under Pb concentration of 0.5% and 1.0% giving 5.76%, 50.43% increases in height, 42.68%, 253.36% increase in fresh wt., and 237.69%, 325.97% increase in dry wt. Regarding the plant nutrient, NPK contents the non-inoculated Pb–treated plants gave significantly the highest N content under all Pb concentration levels and the highest PK contents under Pb concentrations 0.5 and 1.0% compared to the bio-remediated plants. But the bio-remediated plants dominated the non-inoculated Faba bean plants in absorbing the highest PK contents under a Pb concentration of 5.0%. Regarding Pb absorption, the bio-remediated plants dominated the non-inoculated Faba bean plants and absorbed the highest Pb especially under 1.0% Pb concentration. Bacillus amyloliquefaciens subsp. plantarum UCMB 5033 may be considered a bio-remediator for Faba bean plants grown under Pb contaminated soils.

Landscape crop diversity and semi-natural habitat affect crop pollinators, pollination benefit and yield

Agricultural intensification has led to the conversion of natural habitats into agricultural fields, increased field sizes and simplified crop rotations. The resulting homogenisation of the landscape has led to a decline in bees, which provide an essential ecosystem service to agriculture. It has been suggested that an increase in landscape crop diversity supports higher biodiversity by providing more diverse and continuous resources without taking land out of agricultural production. We selected 14 faba bean (Vicia faba minor L.) fields in southern Sweden along uncorrelated gradients of landscape crop diversity and proportion of semi-natural habitat within 1.5 km radii surrounding focal fields. Pollinator surveys and pollinator exclusion experiments were conducted to assess whether landscape crop diversity affected pollinator densities, pollinator foraging behaviour (i.e. legitimate flower visitation, nectar robbing or extra-floral nectary visitation), pollination and yield formation. Landscape crop diversity enhanced bumble bee densities. Insect-pollinated faba bean plants produced, on average, 27 % higher bean weight per plant than bagged plants and the insect pollination benefit decreased with increasing semi-natural habitat cover. Bumble bee and honey bee densities, the proportion of nectar robbing bees as well as faba bean yield increased with increasing proportion of semi-natural habitat. Pollinator densities were not the driver of high yields associated with higher proportions of semi-natural habitat because the observed yield increase was unrelated to pollinator densities and driven by bagged plants that were excluded from pollinator visits. Insect pollination, however, clearly decreased the yield gap associated with low proportions of semi-natural habitat in the landscape. Our results highlight that agri-environmental policies should promote the retention of existing semi-natural habitats and encourage landscape crop diversity to provide pollinators with sufficient food and nesting resources.

A new pest management strategy: transforming a non-host plant into a dead-end trap crop for the diamondback moth Plutella xylostella L.

The use of trap crops can reduce the egg production of female Plutella xylostella in cruciferous vegetables and is an effective method for controlling this pest. To date, most of the trap plants that have been studied are cruciferous plants containing high concentrations of glucosinolates, which are more attractive to P. xylostella female adults. However, the application of these trap plants also has some limitations. Studies have shown that aqueous extracts of cruciferous plants can attract P. xylostella to lay eggs. In this study, we utilized the extract of Chinese kale to treat a non-host plant, the faba bean, and evaluated the possibility of using it as a dead-end trap plant for P. xylostella control. Plutella xylostella females laid significantly more eggs on faba beans that had been sprayed with the extract of Chinese kale rather than on Chinese kale itself. The first instar larvae of P. xylostella failed to survive on faba beans. Notably, the faba beans with the Chinese kale extract had the strongest attraction effect on P. xylostella females when placed 3 m away from the Chinese kale. Moreover, this attraction effect of faba beans on P. xylostella for oviposition lasted for up to 15 days. Faba bean plants sprayed with the aqueous extract of Chinese kale represent a potential dead-end trap plant for P. xylostella adults and their oviposition while being invariably deadly for their offspring. The present study provides a new proof of concept of using a non-cruciferous trap plant for P. xylostella management.

Significance of Some Soil Amendments to Improve Plant Growth and Nutrients Uptake in Some Soils

Many problems facing sandy, calcareous and heavy clay soils and restricts plant growth, nutrients availability and sustainable agriculture. Soil amendments are considered to be the most realistic soil management methods to improve soil chemical and physical properties. Improving some soil physical and chemical properties, study the correlation between soil properties and their effect on plant growth and nutrients uptake by faba bean plant (Vicia faba L. var.716) were the main purpose of this study. To achieve this purpose three factorial pot experiments were conducted by addition rates (0, 5 and10 ton. fed-1 ) of farmyard manure (FYM), phosphate rock (PhR) and rice straw (RS) either alone or mixed to sandy, calcareous sandy loam and clay soils. Soils were incubated with the studied treatments for 15 days before planting. The main results showed that the addition rates of soil amendments led to slightly increase in soil salinity, total porosity and significant increase in organic matter content in the experimental soils. Bulk density and pH decreased with increased the rates of FYM and PhR either alone or mixed with RS. Decreasing in hydraulic conductivity in sandy and sandy loam soils, while it increases in clay soil. Generally, there are negative correlations between soil organic matter and both of hydraulic conductivity and bulk density in sandy and sandy loam soils, while, organic matter and hydraulic conductivity gave a positive effect in clay soil. Changes in soil properties had a positive effect of faba bean growth and macro nutrients uptake. The highest rates of the studied materials showed a significant increase in fresh and dry weight, NPK content and uptake of faba bean plant. Integrated use of the highest rates of FYM and PhR with RS were the best option for sustaining physical and chemical properties, enhancing faba bean growth and nutrients uptake of the studied soils.

Phosphorus deficiency enhances water deficit impact on some morphological and physiological traits in four faba bean (<em>Vicia faba L.</em>) varieties

Moroccan soils, generally present low available phosphorus (P) levels which occur in almost all arid and semi-arid regions. Faba bean is one of the most significant crops in Morocco and is influenced by these constraints that affect its nutrient uptake and nitrogen fixation capacity and hence plants development. Therefore, we evaluated the response of four Vicia faba varieties - Aguadulce (Ag), Alfia (Al), Luz de Otono (LO) and Reina Mora (RM) -, grown under biological nitrogen fixation to water deficit and two phosphorus levels. The trial was conducted under greenhouse conditions and water stress was induced by keeping pots at 40% substrate field capacity (FC) versus 80% FC for the controls while phosphorus deficiency treatment consisted in the application of 25 μmol P plant−1 week−1 versus 125 μmol P plant−1 week−1 for sufficient P treatment. The results revealed a significant effect of water deficit and phosphorus deficiency either alone or combined on plants dry weights, leaf water parameters and nutrient concentrations. However sufficient phosphorus supply mitigated the adverse effects of water deficit on faba bean. We noticed significant differences between the studied varieties. Ag showed high performance concerning dry weights (1.25 g and 1.88 g plant–1 respectively for shoot and root) and high concentration of nitrogen N (4.7%) and P (0.27 mg g–1 DW) and was then qualified as the most tolerant variety to water deficit combined with P limitation. While RM was the least tolerant variety, as it showed the lowest dry weights (0.51 g and 1.4 g plant–1 respectively for shoot and root) and concentration (2.74% and 0.19 mg g–1 DW respectively for N and P). The tolerance was related to the ability to ensure efficient osmoregulation by glycine betaine accumulation, to keep leaf water balance and cell membrane stability that contribute together with adequate symbiotic nitrogen fixation to plant growth performance under combined stresses.
 Highlights - Varieties tolerant to low phosphorus and water deficiency are needed in arid and semi-arid regions with low P. - Phosphorus nutrition is advantageous for mitigating the effect of water deficit on faba bean (Vicia faba) plants and conversely, deficient P supply reduces resilience to water deficit. - The faba bean variety Aguadulce showed high tolerance to the combined effect of water deficit and phosphorus deficiency in terms of growth, leaf water potential, stomatal conductance, membrane permeability and glycine betaine accumulation. - Reina Mora was the least tolerant variety to water deficit combined with P limitation. - Combined limitation of water and phosphorus induced accumulation of glycine betaine in leaves.

Efficacy of Mushroom Metabolites (Pleurotus ostreatus) as A Natural Product for the Suppression of Broomrape Growth (Orobanche crenata Forsk) in Faba Bean Plants.

Broomrape parasitism on faba bean (Vicia faba L.) is the most destructive factor for this crop in Egypt. Pot experiments were conducted during the two successive seasons 2017/2018 and 2018/2019 to study the mitigation of broomrape stress on faba bean using a ten-fold dilution of 10% (w/v) spent mushroom substrate extract (SMSE) of Pleurotus ostreatus and the same dilution of culture filtrate of mushroom (MCF) grown in potato dextrose broth (PDB) at a rate of 48 l hectare−1 compared with the commercial herbicide Roundup (Glyphosate 48% emulsifiable concentrate) at a rate of 144 cm3 ha−1 on the two varieties (Misr3 and Sakha3) cultivated in broomrape-infested soil. The treatments include the use of mushroom products as foliar spray and/or soil amendment in addition to Roundup spraying as a recommended treatment. Using Gas Chromatography-Mass Spectrometry (GC-MS) spectroscopy, our results indicate that the major components of the two mushroom products were bioactive compounds such as polyphenol and high molecular weight aliphatic and aromatic hydrocarbons that may interfere with parasite and host metabolism. These results indicated that SMSE of P. ostreatus and MCF of the same mushroom grown in potato dextrose broth (PDB) gave the best control of broomrape, and increased plant height, root length, leaf area, chlorophyll concentration, relative water content and seed yield (g plant−1), as well as anatomical characters of leaves in the two faba bean varieties (Misr3 and Sakha3), such as upper and lower epidermis, palisade tissue, spongy tissue and vascular bundles. Additionally, electrolyte leakage was decreased in the treated plants compared to control plants and the plants treated with Roundup (glyphosate) because of the important role of SMSE and MCF in the improvement of faba bean water status.

Field Performance of Trichoderma harzianum AAUT14 and Bacillus subtilis AAUB95 on Faba Bean (Vicia faba L.) Growth Promotion and Management of Chocolate Spot (Botrytis fabae Sard.)

Aims: This study was done to evaluate the effects of T. harzianum AAUT14 and B.subtilis AAUB95 on chocolate spot (B. fabae) and growth promotion of faba bean.
 Study Design: A completely randomized block design was utilized.
 Place and Duration of Study: The study was conducted at Kulumsa Agricultural Research Center, 8º2'N and 39º10’E, Kulumsa, June-November, 2018.
 Methodology: Two trails (Trial-1 Ashebeka and Trial-2 Hachalu) were employed. We included T1-Control (B.f only); T2-T. harzianum AAUT14+ B.f; T3-B. subtilis AAUB95+B.f; T4-T. harzianum AAUT14+B. subtilis AAUB95+B.f; T5- MORE 720 WP+B.f; T6- ORZEB+B.f as treatments of the study. The disease development was assessed together with yield and related parameters.
 Results: In trail 1, a reduction that varied from 31-61% for disease incidence and 13-33% of severity over T1 upon 70 days after sowing. Upon 90 days, the disease incidence and severity was reduced to 20-50% and 36-51%, respectively. Trichoderma harzianum AAUT14+B.subtilis AAUB95 (T4) reduced the disease incidence and severity showing no significance difference (P=.05) with the chemical fungicide, MORE 720 WP (T5) upon 70 and 90 days of sowing. In trial 2, the microbial inoculants reduced the disease incidence and severity to 28-63% and 17-30% upon 70 days. Likewise, the disease incidence and severity was reduced to 23-51% and 37-54% upon 90 days. In addition, the AUDPC ranged from 1586.1-2250.0%DSU in trial 1 and 1382.0-2454.5%DSU in trial 2. Moreover, leaf area of 68.95cm2 was displayed by T4 in trial 1 and 54.14cm2 in trial 2. In addition, T 4 indicated, 62% and 49% increment of hundred seed dry weight and grain yield estimate in trial 1, and 56% and 55%, increase in trial 2 compared to the uninoculated control. The percentage of healthy pods was 90% and 88.87% in trial 1 and 2, respectively, in the treatment that received T4 and followed by T2 that showed 70.40 and 78.86% in trial 1 and 2, respectively. T4 resulted 4391.45kg/ha and 4378.12kg/ha, that followed by T2 with 3764.58kg/ha and 3654.17kg/ha of yield estimate in trial 1 and 2, respectively. 27-42% and 26-41% of harvest index was exhibited in trial 1 and trial 2, respectively. Furthermore, the seed nitrogen content increased from 33-70% in trial 1 and 29-62% in trial 2. The seed nitrogen content showed 33-70% and 29-62% increment in trial 1 and 2, respectively. Even though the fungicides (T5 and T6), protected the faba bean plants from chocolate spot, there was <10% of seed nitrogen and crudeprotein content increment over the untreated control plants in both varieties.
 Conclusion: The mixture of T. harzianum AAUT14 and B. subtilis AAUB95 or in some cases T. harzianum AAUT14 performed best on controlling chocolate spot, growth promotion and yield increment of faba bean.

Inhibition of Verticillium Dahliae and Rhizoctonia Solani Growth by Solid Phosphate Sludge Amendments

Background: In Morocco, phosphate processing generates large quantities of sludge which amass, form fillings, reduce arable land and distort the landscape. Phosphate wash sludge is rich in mineral elements. In order to recover some of these mineral elements including phosphorus, we considered using this sludge in a nursery as a substrate. Objective: The aim of the study was to check the effect of solid phosphate sludge amendment on some of the main soil-borne pathogens: Verticillium dahliae Kleb. and Rhizoctonia solani Kühn. Materials and Methods: The pathogens have been isolated and identified in the laboratory of Plant Pathology and Postharvest Quality of INRA-Kenitra. Phosphate wash sludge used was originated from the Khouribga phosphate treatment sludge disposal site. Different concentrations of phosphate sludge (0, 10, 30, 50, and 100 g/l) were tested on a PDA-based medium, in three replicates. The inhibitory effects on mycelial growth were measured and compared with those on the soil used by nurseries (Maamora forest soil). Petri dishes with PDA alone were used as control. The same concentrations (10, 30, 50 and 100 g/kg) were tested in vivo on two varieties of tomato and on Faba Faba bean for Verticillium dahliae and Rhizoctonia solani, respectively. Results: The results of this study showed that there was significant growth inhibition at different concentrations of solid Phosphate sludge amendments in vitro. The highest inhibition percentage was observed at 100 g/l of phosphate sludge amendments with 42% and 75% for Verticillium dahliae and Rhizoctonia solani. The high concentrations of phosphate sludge have shown lower disease severity of Verticillium dahliae on the tomato plants and a disease index of Rhizoctonia solani on the Faba bean plants. Conclusion: Based on these results, we can recommend that solid phosphate sludge can be used or mixed with other substrates in nurseries.

Impact of Co-Inoculation with Rhizobium leguminosarum and some Plant Growth Promoting Rihzobacteria against Rhizoctonia solani and Fusarium oxysporum Infected Faba Bean

Plant Growth Promoting Rhizobacteria (PGPR) were evaluated individually or in combination and compared to the fungicide Topsin M-70® for their antagonistic activities and suppressive actions against Fusarium oxysporum and Rhizoctonia solani severally, which were deemedthe causal agents of root rot and wilt diseases of faba bean plants. In vitro, most of the examined strains showed eminent abilities to inhibit mycelial growth of Rhizoctonia solani or Fusarium oxysporum. Strains of Rhizobium leguminosarum (No.9), Azotobacterchroococcum (No.12) and Pseudomonas fluorescens (No. 6) recorded the highest inhibition zone against two tested pathogenic fungi and were used in the present study. Generally, under greenhouse and field conditions, all the tested PGPR strains significantly reduced root-rot and wilt incidence and increased the percentage of survived plants compared to control (infested soil). Combination among R. leguminosarum+ A. chroococcum + P. fluorescens was more effective in controlling root-rot and wilt diseases, increasing growth parameters, yield components, photosynthetic pigments, activities of nitrogenase, dehydrogenase and total phenols. Obtained results clarified the importance of PGPR in controlling pathogenic fungi, enhancing growth parameters of faba been plants compared to chemical fungicide and lowering chemical fertilizers application.

Salt-tolerance in Vicia faba L. is mitigated by the capacity of salicylic acid to improve photosynthesis and antioxidant response

Selection and improvement of crops subjected to salinity constitutes an urgent need for increasing agricultural and food production in order to feed the growing human population. The aim of the present study is to evaluate the role of salicylic acid (SA) application in mitigating the adverse effects of salinity on faba bean (Vicia faba L.) at the physiological and molecular levels. Fort this purpose, two faba bean genotypes were subjected to various concentrations of NaCl and salicylic acid in a full factorial design. After that, growth, water status, gas exchanges, photosynthesis parameters, ions homeostasis and antioxidant enzymes activities were evaluated. The obtained results demonstrated that salinity induced several limitations in plants growth and physiological attributes. In response, salt stressed faba bean plants improved water status and enhanced antioxidant enzymatic activities. Remarkably, salt-tolerance of both genotypes was significantly improved by salicylic acid application which allowed the maintenance of cell membrane and photosynthetic process, restoring of ion homeostasis and the diminution of oxidative damages. Overall, the difference between genotypes is rather quantitative than qualitative even if the genotype Aguadulce displayed better growth, physiological and molecular response under salt stress than the genotype Histal. Besides, the beneficial effects of salicylic acid vary according to its concentration, the tested genotype and the studied parameter; the genotype Aguadulce performs better under the treatment with 0.5 mM SA while the genotype Histal manifests greater behaviour under the treatment with 1 mM SA. Therefore, salicylic acid can be considered as potential growth regulator to improve the salt response of faba bean. The application of salicylic acid would provide a practical basis for wide cultivation of faba bean in marginal and wastelands under-cultivated and might propose an effective ecological and economical alternative solution to deal with salt-affected soils mainly in arid regions.

Effect of Inoculation with Rhizobium, Plant Growth Promoting Rhizobacteria and Foliar Spraying with Boron and Molybdenum on Growth, Nodulation and Productivity of Faba Bean تأثیر التلقیح بالریزوبیا والریزوبکتیریا والرش الورقى بالبورون والمولبیدنیم على النمو وتکوین العقد الجذریة والانتاجیة للفول البلدى.

A field trial was conducted at El-Gemmeiza Agricultural Research Station Elgharbia Governorate, Egypt, during the two successive seasons of 2017/2018 and 2018/2019 to study the response of faba bean (Vicia faba) to inoculation with Rhizobium leguminosarum, rhizobacteria Bacillus polymyxa [as plant growth promoting rhizobacteria (PGPR)] either solely or in combination and foliar spraying of boron (B), molybdenum (Mo) either alone or in combination and their effect on nodulation, growth and productivity. Results could be summarized as follows: Inoculated faba bean plants with Rhizobium leguminosarum + Bacillus polymyxa obtained the maximum values of plant height, leaf area index, total dry matter plant-1, crop growth rate, pods number plant-1, seed yield plant-1, 100-seed weight, seeds and straw yields/fad, as well as number and dry weight of nodules, total chlorophyll of leaves, phosphorus, nitrogen and protein of seeds. The foliar spraying of 30 ppm B + 15 ppm Mo on faba bean plants gave the maximum values for plant height, leaf area index, total dry matter plant-1, crop growth rate, pods number plant-1, seed yield plant-1, 100-seed weight, seeds and straw yields/fad, as well as nodules number and dry weight, total chlorophyll of leaves, phosphorus, nitrogen and protein of seeds. inoculated faba bean plants with Rhizobium leguminosarum + Bacillus polymyxa plus foliar spraying by 30 ppm B + 15 ppm Mo obtained the highest values for all mentioned traits, such treatment increased seeds and straw yields as well as protein content of seeds by 42.92, 33.08 and 21.32%, respectively compared to control.

Thermal Effects on the Population Parameters and Growth of Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae).

The pea aphid Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) is a cosmopolitan and polyphagous species. An evaluation of A. pisum’s demographic parameters and growth was carried out after rearing aphids on faba bean plants (Vicia faba) under five different temperature conditions (10 °C, 15 °C, 20 °C, 25 °C and 30 °C). We analyzed the raw life history data, including developmental time, survival, longevity and reproduction, using an age-stage, two-sex life table to consider variable developmental rates among individuals. The population fluctuation of A. pisum determined the stage-specific population structure and potential population growth under different temperature conditions. A. pisum individuals developed successfully from nymphs to adults at all temperatures in this study. The developmental rate of A. pisum increased as the temperature increased. Our results indicated that A. pisum showed a higher pre-adult mortality, lower total fecundity and a negative intrinsic rate of increase at 30 °C. The highest intrinsic rate of increase (0.30) and finite rate of increase (1.35) were observed at 25 °C. Comparisons of population parameters and their analytical methods between different A. pisum populations from other geographic areas are also discussed.

EFFECT OF SPRAYING ASCORBIC ACID AND SALICYLIC ACID ON THE GROWTH AND YIELD OF FABA BEAN(VICIA FABA L.) GROWING IN SALT SOIL

A pot experiment was conducted in the Department of Soil Sciences and Water Resources at the College of Agriculture / Diyala University for the agricultural season 2018-2019. The seeds were planted in saline soils (EC = 8.1 dS m-1 ). The results showed that the treatments used in the research exceeded the comparison treatment in improving the growth and yield characteristics of the faba bean plant. All the treatments were significantly increase of plant height, fresh weight of shoot, dry weight of shoot and fresh weight of the pod comparison with control, all treatments were significantly increase of dry weight of pod except for the treatment of the first concentration of salicylic acid (SA1). While the treatment of the first level of both acids (AsA1SA1) and the interaction between the second concentrations of ascorbic acid with the first concentration of salicylic acid (AsA2SA1) were significantly superior compared to the comparison treatment in increasing the number of branches / plant.

Mitigating effects of Bean yellow mosaic virus infection in faba bean using new carboxymethyl chitosan-titania nanobiocomposites

Bean yellow mosaic virus (BYMV) is the main cause of the mosaic and malformation of many plants, worldwide. Thus, the triggering of plant systemic resistance against BYMV is of great interest. In this endeavor, we aimed to explore the capacity of new carboxymethyl chitosan-titania nanobiocomposites (NBCs, NBC1,2) to trigger faba bean plants resistance against BYMV. Effects of NBCs on faba bean (Vicia faba L.) disease severity (DS), growth parameters, and antioxidant defense system activity were investigated under BYMV stress. Noticeably that the DS in NBCs-treated faba bean was significantly reduced compared to untreated plants. Moreover, treatment with NBCs was remarkably increased growth indices, photosynthetic pigments, membrane stability index, and relative water content compared to challenge control. Additionally, enzymatic and non-enzymatic antioxidants and total soluble protein were significantly increased. Contrary, electrolyte leakage, hydrogen peroxide, and lipid peroxidation were reduced. Interestingly that NBC1 has higher efficacy than NBC2 in triggering plant immune-system against BYMV as indicated from DS percentage (DS = 10.66% and 19.33% in case of plants treated with NBC1 and NBC2, respectively). This could be attributed to the higher content of TNPs in NBC1 (21.58%) as compared to NBC2 (14.32%). Overall, NBCs offer safe and economic antiviral agents against BYMV.

Variation in antioxidant metabolism of faba bean (Vicia faba) under drought stress induced by polyethylene glycol reveals biochemical markers associated with antioxidant defense

Antioxidative responses in faba bean plants subjected to different osmotic potentials induced by PEG-6000 were investigated. Drought stress significantly decreased photosynthetic gas exchange parameters (net CO2 assimilation rate, transpiration rate, internal concentration of CO2 and stomatal conductance) and leaf RWC in Bachar and Giza 3, while the magnitude of reduction in Bachar was relatively low. This could be due to its better antioxidant enzyme activities (catalase, superoxide dismutase and ascorbate peroxidase) and higher transcription levels of their respective genes. Moreover, the accumulation of proline and soluble sugars, combined with enhanced total phenolics content, total flavonoid content, and total antioxidant capacity may play important roles in drought tolerance in faba bean, thereby increasing osmotic adjustment and protection from free radicals. In agreement with this assumption, Bachar displayed lower MDA and H2O2 content and lower electrolyte leakage than Giza 3. Moreover, the detected increase in antioxidant enzyme activities appeared to be correlated with mRNA levels. Enzymatic and non-enzymatic (phenolic and non-phenolic) antioxidants may be useful as biochemical markers of oxidative stress responses to differentiate drought tolerant faba bean cultivars under drought stress. In the study, Bachar was found to be relatively tolerant to drought stress and Giza 3 was sensitive.

Bradyrhizobium japonicum strain Asw1 colonizing cowpea ( Vigna unguiculata L.) roots mediates eco-physiological and growth responses in faba bean ( Vicia faba L.) and wheat ( Triticum aestivum L.)

In the Twenty-First Century, the greatest challenge in the agriculture is the increment of the crop productivity with reducing the harmful implications resulting from the utilization of chemical fertilization. Plant-microbe interaction provide an essential function for plant growth promotion and crop productivity with safety management and controlling ecosystems pollution. In this research, Bradyrhizobium japonicum strain Asw1 (accession no. MN079045) isolated from Vigna unguiculata (L.) nodules were used to mediate some important eco-physiological responsiveness included the photosynthetic rate (Pn), transpiration rate (Tr), stomatal conductance (Gs) and leaf water-use efficiency (WUE) in faba bean and wheat plants. The results obtained indicated that the inoculation with strain Asw1was significantly (p˂0.05) enhanced the eco-physiological and growth responses in both plant species. Our research provides a considerable sign for the benefit use of Bradyrhizobium japonicum Asw1as plant growth promoting symbiotant. Therefore, we suggest the exploitation of strain Asw1 in large scale, in the agricultural purposes.

Antifungal potential of extracts produced from decomposed agricultural wastes by Bosea thiooxidans

This work aimed to produce antifungal bioactive compounds from agro-wastes using cellulolytic bacteria, and to evaluate their in vitro and in vivo antifungal activities against faba bean damping off disease caused by Rhizoctonia solani. To achieve this purpose, a total of 34 rhizospheric bacterial isolates were screened for their abilities to degrade cellulosic compounds. The bacterial isolate which gave the best cellulolytic activity was identified as Bosea thiooxidans, according to its morphological, biochemical characteristics, and according to its 16S rRNA sequencing. Five native plants remains including; Pomegranate peel, chili waste, prickly peel, olive leaves and garlic stalks, were hydrolyzed by the selected cellulolytic B. thiooxidans strain UAB7, and their extracts were tested for in vitro antifungal potential against a number of fungal phytopathogens mainly; Rizoctonia solani, Fusarium moniliform; Pythium sp. and Phytophothora sp. Extracts of the decomposed garlic and olive wastes gave inhibition percentages ranging from 25-100%, against the tested fungal pathogens. Transmission electron microscopy (TEM) showed cyto-morphological alterations and empty cavities in hyphae of the treated R. solani. Moreover, qualitative and quantitative analyses of the phenolic compounds present in the tested extracts were carried out. Results showed that among the tested phenolic compounds, kaempferol and phenanthrene were more abundant in the decomposed garlic and olive extracts, respectively. The fermented garlic and olive extracts were evaluated for their in vivo potency to suppress the damping off disease of faba bean caused by R. solani. Faba bean plants treated with the fermented garlic and olive extracts demonstrated significantly better disease suppression, compared to the infested control. Furthermore, bands recovered through the electrophoretic patterns of the superoxide dismutase and peroxidase isozymes in the infested control plants, showed wide differentiation in their intensities and forms, compared to the healthy and the treated plants.

Alleviation of drought stress in faba bean (Vicia faba L.) by exogenous application of β-aminobutyric acid (BABA).

Drought stress is one of the most prevalent environmental factors limiting faba bean (Vicia faba L.) crop productivity. β-aminobutyric acid (BABA) is a non-protein amino acid that may be involved in the regulation of plant adaptation to drought stress. The effect of exogenous BABA application on physiological, biochemical and molecular responses of faba bean plants grown under 18% PEG-induced drought stress were investigated. The results showed that the application of 1mM of BABA improved the drought tolerance of faba bean. The application of BABA increased the leaf relative water content, leaf photosynthesis rate (A), transpiration rate (E), and stomatal conductance (gs), thereby decreased the water use efficiency. Furthermore, exogenous application of BABA decreased production of hydrogen peroxide (H2O2), malondialdehyde and electrolyte leakage levels, leading to less cell membrane damage due to oxidative stress. Regarding osmoprotectants, BABA application enhanced the accumulation of proline, and soluble sugars, which could improve theosmotic adjustment ability of faba bean under drought challenge. Interestingly, mended antioxidant enzyme activities like catalase, guaiacol peroxidase, ascorbate peroxidase and superoxide dismutase and their transcript levels may lead to counteract the damaging effects of oxidative stress and reducing the accumulation of harmful substances in BABA-treated faba bean plants. In addition, exogenous BABA significantly induced the accumulation of drought tolerance-related genes like VfMYB, VfDHN, VfLEA, VfERF, VfNCED, VfWRKY, VfHSP and VfNAC in leaves and roots, suggesting that BABA might act as a signal molecule to regulate the expression of drought tolerance-related genes.

Effect of Exopolysaccharide-Producing Bacteria and Melatonin on Faba Bean Production in Saline and Non-Saline Soil

Soil salinity is a major threat to modern agriculture, as it affects crop growth and development. The present study focuses on the integration of eco-friendly biostimulants in salinity stress as a strategy to achieve the alleviation of abiotic stress. Field experiments were conducted at two locations, consisting of saline and non-saline soil, to investigate the utilization of exopolysaccharide (EPS)-producing bacteria (Azotobacter chroococcum) and melatonin at different concentrations (0, 25, 50, and 100 µM) for alleviating the adverse effects of salinity on the growth and production of faba bean plants. Salinity stress caused a reduction in all measured parameters of the faba bean plants grown in the saline soil relative to the plants grown in the non-saline soil. The addition of bacteria and/or melatonin significantly increased the growth parameters and yield components under both soils compared to the respective control plants. Both bacteria inoculation and melatonin application enhanced N, P, and K concentrations; the proline content; RWC%; and the K+/Na+ ratio; however, Na+ and Cl− concentrations were decreased significantly in salt-stressed faba beans. The combined use of bacteria and melatonin exhibited the highest stimulating effects. The present study recommends the combined use of EPS-producing bacteria and melatonin for the salinity stress management strategy of faba bean.