Uninoculated Control Research Articles

Studies on Stover Yield of Maize with Basal Application of Fertilizer and Foliar Spraying of Gluconacetobacter diazotropicus on Available Nutrients in Soil

The experiment on “Studies on Stover yield of maize with basal application of fertilizer and foliar spraying of Gluconacetobacter diazotropicus on available nutrients in soil” was carried out during Kharif 2022 in the experimental filed under Department of Soil Science & Agricultural Chemistry. The experiment was carried out according to a randomized block design (RBD) with 3 replication including 18 treatments of the microbial consortium Arthrobacter sp., phosphate-solubilizing bacteria (Bacillus sp.) and soluble bacteria. There is also Gluconacetobacter diazotrophicus sprayed on leaves at 25, 45 and 65 DAS of the plant growth stages. Maize seeds (cv. JM 216, duration 110 days, sowing 20 kg/ha) were sown in the specified plot (size 3mx2m) on June 28, 2022, with a distance of 60 and 20 cm. Plants are supplemented with the recommended dose of fertilizer 120:60:40 (Nitrogen:P2O5:K2O kg/ha) in basic fertilization. Additionally, two types of control plots were maintained: fertilized un-inoculated (FUI) control plots and un-inoculated (UFUI) control plots. Regarding the study of main nutrients in the soil at harvest time, the combination of similar treatments also increased N, P and K by 21.31, 21.31 and 60.6%, respectively. The most effective treatment was performed systematically by a combination of RDF+Arthro+PSB+KSB treatments for all parameters. Simultaneous inoculation of biological products G. diazotropicus, Arthrobacter, PSB (Bacillus sp.) and KSB (Frateuria aurantia) when treating seeds and foliar fertilizing maize increased growth and the ability to provide important nutrients in the soil at harvest time. This is the positive impact of G.diazotropicus and Arthrobacter The data on stover yield ranged from 5618- 10729 kg/ha. All the treatments (except G. diazotropicus) increased significantly the grain yield over the control fertilized uninoculated (FUI). Among all the treatment combinations.

Enhancing cadmium phytoremediation of Chlorophytum comosum (Thunb.) Jacques by applying cadmium-resistant bacterial tablet.

This study aims to formulate bacterial tablets of cadmium (Cd)-resistant Micrococcus sp. MU1, an indole-3-acetic acid-producer, for soil inoculation to improve Cd phytoremediation by Chlorophytum comosum (Thunb.) Jacques. The viability of Micrococcus sp. MU1 in tablets after storage at room temperature and 4 °C was determined. The ability of Micrococcus sp. tablets and cell suspensions on stimulating growth and Cd accumulation in C. comosum was compared. The results found that the viability of Micrococcus sp. tablets stored at room temperature and 4 °C for 2 months were 29.2 and 97.9%, respectively. After 2 months of growth in pots, the dry biomass weights of C. comosum amended with Micrococcus sp. tablet and cell suspension were greater than that of uninoculated control by 1.4- and 1.3-fold, respectively. Cd concentrations in the roots and shoots of C. comosum inoculated with bacterial tablet and bacterial suspension were not significantly different (p < 0.05) and were greater than that of the uninoculated plants. In addition, plants inoculated with Micrococcus sp. tablet and cell suspension exhibited superior phytoextraction performance, bioaccumulation factor, and translocation factor, indicating equal performance of both bacterial forms on boosting Cd phytoremediation efficiency in C. comosum. These findings suggest that soil inoculation with Micrococcus sp. tablet as a ready-to-use inoculum is a novel approach to promote phytoremediation of C. comosum in Cd-contaminated agricultural soil.

Comparative efficacy of different salt tolerant rhizobial inoculants in improving growth and productivity of Vigna radiata L. under salt stress

Worldwide, salinity severely affects agricultural production of crops such as mung bean in arid and semi-arid regions. In saline conditions, various species of Rhizobium can be used to enhance nodulation and induce salinity tolerance in maize. The present study conducted a pot experiment to determine the efficiency of three rhizobial isolates under different salinity conditions, such as 1.41, 4 and 6 dS m−1, on mung bean growth parameters, antioxidant status and yield. Results revealed that salt stress imparted adverse effects on the growth, antioxidants, yield and nodulation of mung bean. Under high salt stress conditions, fresh weights were reduced for roots (78.24%), shoots (64.52%), pods (58.26%) and height (32.33%) as compared to un-inoculated control plants. However, an increase in proline content (46.14%) was observed in high salt stressed plants. Three Rhizobium isolates (Mg1, Mg2, and Mg3), on the other hand, mitigated the negative effects of salt stress after inoculation. However, effects of Mg3 inoculation were prominent at 6 dS m−1 and it enhanced the plant height (45.10%), fresh weight of shoot (58.68%), root (63.64%), pods fresh weight (34.10%), pods number per plant (92.04%), and grain nitrogen concentration (21%) than un-inoculated control. Rhizobium strains Mg1, and Mg2 expressed splendid results at 1.41 and 4 dS m−1 salinity stress. The growth promotion effects might be due to improvement in mineral uptake and ionic balance that minimized the inhibitory effects caused by salinity stress. Thus, inoculating with these strains may boost mung bean growth and yield under salinity stress.

Mineral Solubilizing Rhizobacterial Strains Mediated Biostimulation of Rhodes Grass Seedlings.

Minerals play a dynamic role in plant growth and development. However, most of these mineral nutrients are unavailable to plants due to their presence in fixed forms, which causes significant losses in crop production. An effective strategy to overcome this challenge is using mineral solubilizing bacteria, which can convert insoluble forms of minerals into soluble ones that plants can quickly assimilate, thus enhancing their availability in nutrient-depleted soils. The main objective of the present study was to isolate and characterize mineral solubilizing rhizobacteria and to assess their plant growth-promoting potential for Rhodes grass. Twenty-five rhizobacterial strains were isolated on a nutrient agar medium. They were characterized for solubilization of insoluble minerals (phosphate, potassium, zinc, and manganese), indole acetic acid production, enzymatic activities, and various morphological traits. The selected strains were also evaluated for their potential to promote the growth of Rhodes grass seedlings. Among tested strains, eight strains demonstrated strong qualitative and quantitative solubilization of insoluble phosphate. Strain MS2 reported the highest phosphate solubilization index, phosphate solubilization efficiency, available phosphorus concentration, and reduction in medium pH. Among tested strains, 75% were positive for zinc and manganese solubilization, and 37.5% were positive for potassium solubilization. Strain MS2 demonstrated the highest quantitative manganese solubilization, while strains MS7 and SM4 reported the highest solubilization of zinc and potassium through acidifying their respective media. The strain SM4 demonstrated the most increased IAA production in the presence and absence of L-tryptophan. The majority of strains were positive for various enzymes, including urease, catalase protease, and amylase activities. However, these strains were negative for coagulase activity except strains SM7 and MS7. Based on 16S rRNA gene sequencing, six strains, namely, SM2, SM4, SM5, MS1, MS2, and MS4, were identified as Bacillus cereus, while strains SM7 and MS7 were identified as Staphylococcus saprophyticus and Staphylococcus haemolyticus. These strains significantly improved growth attributes of Rhodes grass, such as root length, shoot length, and root and shoot fresh and dry biomasses compared to the uninoculated control group. The present study highlights the significance of mineral solubilizing and enzyme-producing rhizobacterial strains as potential bioinoculants to enhance Rhodes grass growth under mineral-deficient conditions sustainably.

Remediation of hydrocarbons and metals by hydrocarbon utilizing Pseudomonas taiwanensis YSA-17 isolated from soil contaminated with petroleum.

Careless handling of petroleum in petrochemical industries releases toxic hydrocarbons and metals to soil and water. The aim of the present study was to isolate hydrocarbon-utilizing and metal-tolerant bacteria. Hydrocarbon-utilizing bacteria from petroleum-contaminated soils were isolated on the Bushnell Hass medium. Hydrocarbon degradation by Pseudomonas taiwanensis strain YSA-17 was observed by gas chromatography-mass spectrometry. Bioaccumulation of metals by strain YSA-17 was assessed in nutrient broth. Among different strains, YSA-17 showed the highest potential for hydrocarbon utilization. After 20 days of incubation, YSA-17 completely degraded one compound and during its degradation, there was the formation of 13 new compounds which were absent in uninoculated control. Results of scanning electron microscope and Fourier transmission infrared (FTIR) indicated degradation of hydrocarbons. FTIR showed the formation of new functional groups in YSA-17 inoculated medium. Expression of the total quantity of hydrocarbon-degrading gene (AlkB and NehAc) in petroleum-amended nutrient broth inoculated with strain YSA-17 enhanced significantly during 20 days of incubation compared to control. YSA-17 also significantly removed metals. This study concluded that bioinoculant can be utilized for the bioremediation of pollutants cocontaminated with hydrocarbons and metals. Petroleum-contaminated soil will be remediated for pollutants.

Microbial inoculants with higher capacity to colonize soils improved wheat drought tolerance.

Microbial inoculants have gained increasing attention worldwide as an eco-friendly solution for improving agriculture productivity. Several studies have demonstrated their potential benefits, such as enhanced resistance to drought, salinity, and pathogens. However, the beneficial impacts of inoculants remain inconsistent. This variability is attributed to limited knowledge of the mechanisms by which microbial inoculants affect crop growth and a lack of ecological characteristics of these inoculants that limit our ability to predict their beneficial effects. The first important step is believed to be the evaluation of the inoculant's ability to colonize new habitats (soils and plant roots), which could provide crops with beneficial functions and improve the consistency and efficiency of the inoculants. In this study, we aimed to investigate the impact of three microbial inoculants (two bacterial: P1 and P2, and one fungal: P3) on the growth and stress responses of three wheat varieties in two different soil types under drought conditions. Furthermore, we investigated the impact of microbial inoculants on soil microbial communities. Plant biomass and traits were measured, and high-throughput sequencing was used to characterize bulk and rhizosphere soil microbiomes after exposure to drought stress. Under drought conditions, plant shoot weight significantly increased (11.37%) under P1 treatments compared to uninoculated controls. In addition, total nitrogen enzyme activity increased significantly under P1 in sandy soil but not in clay soil. Importantly, network analyses revealed that P1, consisting of Bacillus paralicheniformis and Bacillus subtilis, emerged as the keystone taxa in sandy soil. Conversely, P2 and P3 failed to establish as keystone taxa, which may explain their insignificant impact on wheat performance under drought conditions. In conclusion, our study emphasizes the importance of effective colonization by microbial inoculants in promoting crop growth under drought conditions. Our findings support the development of microbial inoculants that robustly colonize plant roots for improved agricultural productivity.

Nitrogen Dynamics in Soil Treated with Plant-Growth Promoting Bacteria and Urea Fertilizer

The mineralization of urea fertilizer significantly impacts nitrogen movement in the soil. An incubation study was done on a lab scale basis to examine nitrogen dynamics in soil inoculated with plant growth-promoting bacteria (PGPB) supplemented with varying levels of nitrogen fertilizer in the form of urea (0% N, 25% N, 50% N, 75% N, and 100% N). In the present experiment, sandy clay loam soil was used and incubated for four weeks, and the concentrations of NH4+‒N and NO3–‒N were monitored using the destructive method (Kjeldahl) to determine the mineralization rate of urea. Results showed higher NH4+‒N (11.880 mg/kg mineralized with UPMRB9N50 treatment) and NO3–‒N (20.060 mg/kg mineralized with UPMRB9N50 treatment) concentrations in the bacteria-treated soil compared to the uninoculated control. Urea-N remains higher (0.0353% and 0.0253% from UPMRB9N50 treatment in the first and second weeks, respectively) in bacteria-treated soil during the first two weeks, then gradually becomes zero towards the end of the observing period. Nitrogen (N) leaching loss was lower in bacterial inoculated soil compared to the control, and the leaching loss of N was greater with the increased N fertilizer rates. Cumulative N leaching loss is higher (29.797 mg/kg) in 100% N-treated soil than in other treatments. The findings observed that the beneficial bacteria could enhance the N mineralization to make the nutrient available for the crop while, at the same time, reducing leaching losses of fertilizer when supplied with a minimum amount of chemical fertilizer, thereby saving the input cost and protecting the environment.

Effect of chemical fertilizers and microbial inoculants on nodulation, yield, uptake of nutrients and quality of soybean [Glycine max (L.) Merrill.

Field experiments were conducted during the rainy season of 2009 and 2010 at Research Farm of Marathwada Agricultural University, Parbhani, to study the effect of chemical fertilizers and microbial inoculants on nodulation, yield, uptake of nutrients (NPKS) and quality of soybean [Glycine max (L.) Merrill.]. The experimental soil was clayey with pH 8.30. It was low in organic carbon, nitrogen and medium in phosphorus and high in potassium. Treatments comprised of three levels of fertility (100% RDF, 75% RDF and control) and four treatments of bioinoculants (Bradyrhizobium, PSB, Bradyrhizobium + PSB and uninoculated control). The experiment was laid out in factorial randomized block design with four replications. The results revealed that application of 75% RDF showed significantly higher number of nodules and leghaemoglobin content in nodules, 100% RDF found to have higher grain and strawyields, total nutrient uptake (NPKS) and quality parameters ofsoybean. Combined inoculationwith Bradyrhizobium+ PSB recorded significantly higher nodule character leghaemoglobin content of nodule, yield, nutrient, uptake and quality parameters of soybean.

Unveiling novel insights into haloarchaea (Halolamina pelagica CDK2) for alleviation of drought stress in wheat.

Plant growth promoting microorganisms have various implications for plant growth and drought stress alleviation; however, the roles of archaea have not been explored in detail. Herein, present study was aimed for elucidating potential of haloarchaea (Halolamina pelagica CDK2) on plant growth under drought stress. Results showed that haloarchaea inoculated wheat plants exhibited significant improvement in total chlorophyll (100%) and relative water content (30.66%) compared to the uninoculated water-stressed control (30% FC). The total root length (2.20-fold), projected area (1.60-fold), surface area (1.52-fold), number of root tips (3.03-fold), number of forks (2.76-fold) and number of links (1.45-fold) were significantly higher in the inoculated plants than in the uninoculated water stressed control. Additionally, the haloarchaea inoculation resulted in increased sugar (1.50-fold), protein (2.40-fold) and activity of antioxidant enzymes such as superoxide dismutase (1.93- fold), ascorbate peroxidase (1.58-fold), catalase (2.30-fold), peroxidase (1.77-fold) and glutathione reductase (4.70-fold), while reducing the accumulation of proline (46.45%), glycine betaine (35.36%), lipid peroxidation (50%), peroxide and superoxide radicals in wheat leaves under water stress. Furthermore, the inoculation of haloarchaea significantly enhanced the expression of stress-responsive genes (DHN, DREB, L15, and TaABA-8OH) and wheat vegetative growth under drought stress over the uninoculated water stressed control. These results provide novel insights into the plant-archaea interaction for plant growth and stress tolerance in wheat and pave the way for future research in this area.

Deciphering the antifungal and plant growth-stimulating traits of the stress-tolerant Streptomyces achromogenes subsp. achromogenes strain UMAF16, a bacterium isolated from soils affected by underground fires

Crop plants are subjected to diverse abiotic and biotic stresses, which could affect their health and production. Therefore, searching for novel stress-resistant microbial agents with plant-beneficial activities is considered an urgent in agriculture. Here, we report the new stress tolerant bacterium Streptomyces achromogenes subsp. achromogenes UMAF16, isolated from a soil subjected to underground fires. Taxonomic and Genomic analysis derived from ANI (average nucleotide identity) species delimitation cut-off values, GGDC (genome-to-genome distance calculator), and phylogenetic analysis, corroborated the affiliation of UMAF16 to Streptomyces species. Genome mining of UMAF16 shows an excellent arsenal of stress tolerant genes (e.g. temperature, osmotic, and oxidative stress), as well as antifungal and plant growth-promoting mechanisms. Additionally, antiSMASH revealed multiple biosynthetic genes with antimicrobial (e.g. Achromosin, Livipeptin, Neocarazostatin A) and PGP activities (e.g. siderophores like Desferrioxamin B/Desferrioxamine E). To further confirmed previous predicted activities, it was biochemically evaluated the antifungal and plant growth-promoting mechanisms, including production of indole-3-acetic acid (IAA), proteases, siderophores, biofilm formation, and phosphate solubilization. Our results also show that strain UMAF16 grows well at temperature 50 °C, tolerates dehydration stress simulated by polyethylene glycol, and exert antifungal action against pathogens like Alternaria alternata, Mucor fragilis and Fusarium brachygibbosum. Strain UMAF16 also showed growth-stimulating activities when interacting with tomato plants, evaluated under three different plant-growth systems. Root and shoot dry weight, as well as chlorophyll content were increased in inoculated plants, compared to uninoculated controls. Finally, these results suggest a great potential of the strain UMAF16 as a bioinoculant candidate agent in stressful agriculture.

Variety-strain interaction specificity of &lt;i&gt;Bacillus subtilis&lt;/i&gt; with salt-stressed &lt;i&gt;Phaseolus vulgaris&lt;/i&gt; L. plants

The effectiveness of crop inoculation using growth-stimulating bacteria can depend on the plant variety and environmental conditions. The reactions of three-week-old plants of the Ufimskaya and Zolotistaya green bean varieties to inoculation with strains 26D and 10-4 in normal conditions and under stress (1% NaCl 48 h) were analysed. Although the Zolotistaya variety formed less biomass and leaf area, it surpassed the Ufimskaya variety in terms of chlorophyll and root water content, as well as reacting to stress by reducing the content of photosynthetic pigments and root water content. Inoculation contributed to the preservation of these indicators at the level of non–stressed plants: the positive effect of strain 26D was expressed in the effect on the composition of pigments, while that of strain 10-4 was expressed in the hydration of roots. Under stress, the Ufinskaya variety improved the water status of the roots, on which inoculation had a weak or negative effect; however, the decrease in the level of synthetic pigments under stress was compensated by inoculation with both strains. According to the biomass of three-week-old plants, the Zolotistaya variety was shown to respond positively to inoculation with both strains both normally and under stress, while the Ufimskaya variety tended to react negatively to inoculation with strain 26D; under stress, the effect of inoculation with both strains was positive. Compared with the stress-induced control, the malondialdehyde content in the roots of inoculated plants of both varieties decreased in comparison with that of the uninoculated control both in normal conditions and under stress. The revealed differences in plant reactions to inoculation serve as a basis for further analysis of the effectiveness of variety-strain combinations of symbiotic partners.

Characterization of physicochemical and microbial quality, functional properties, and shelf stability of fermented tigernut-based probiotic beverages

Tigernuts and millet are indigenous underutilized crops in West Africa that have versatile applications in food processing. These crops are rich in fermentable carbohydrates, resistant starch, fiber, and micronutrients, making them ideal candidates for pre- and probiotic (synbiotic) foods. This study utilized whole tigernuts in a dairy–millet-based fermented beverage called brukina, turned it to a synbiotic, and assessed the functional and physicochemical profiles, microbial quality, and shelf stability of the beverage. The tigernut–millet agglomerate was prepared by incorporating cellulose-hydrolyzed tigernut fibrous (TNF) cake and non-hydrolyzed TNF (10% and 15%, respectively) into millet and allowing to ferment for 12 and 24 h. Brukina produced from composite tigernut milk: dairy in a ratio of 40%:60% was inoculated with the probiotic Lacticaseibacillus casei after pasteurization. The beverage was analyzed for physicochemical, proximate, and functional properties and microbiological stability at 5°C and 25°C. The obtained data were subjected to analysis of variance (ANOVA) in Minitab version 17 using a general linear model to determine the variability, interactions, and significance of the measured product characteristics. The agglomerate water absorption capacity (l/g) ranged from 0.70 ± 0.17 to 0.89 ± 0.17, bulk density (g/l) from 0.55 ± 0.04 to 0.63 ± 0.00, and swell index (%) from 1.62 ± 0.08 to 1.80 ± 0.06. The agglomerate prepared from dough and fermented for 12 h had excellent functional characteristics and was selected for synbiotic brukina production. Moisture content of the product decreased (p &amp;lt; 0.001) with tigernut incorporation ranging from 78.85% to 70.45%, while sodium, phosphorus, protein, total carbohydrate, and crude fiber increased with tigernut incorporation (p &amp;lt; 0.05). Synbiotic brukina supported the growth of L. casei attaining 11 log CFU/mL with a corresponding increase in lactic acid production and was microbiologically safe at 5°C and 25°C for 5 days compared to unpasteurized and uninoculated probiotic control (p &amp;lt; 0.05). The addition of whole tigernuts and L. casei to brukina enhanced its nutritional content with a shelf stability of 3 days.

Soil microbial population as influenced by different crops and the same crop grown in different locations of Paderu, Andhra Pradesh

Microbial population of soil varies depending on the soil type, climatic conditions, cropping pattern and different cultural practices followed. In the present study, the microbial inoculants with various PGPR were distributed to the farmers of different tribal hamlets. After application of these inoculants, the sampling was made during different crop growth period and microbial population was determined. In general the microbial population was very much improved in the soils of the fields where microbial inoculants were applied. The total microbial population and PGPR viz, Rhizobium, Azospirillum, Azotobacter, PSB, KSB and Pantoea dispersa varied from place to place and in different crops. However, the population was more in plantation crop than other annual crops. In annual crops, the microbial population was more during flowering stage than initial and harvesting stage. This study clearly showed improved microbial population due to application of microbial inoculants in different crops over uninoculated control plots and also more microbial population in plantation crop than in annual crops.

Identification and Pathogenicity of Fusarium Isolated from Soybean in Poland.

Fungi belonging to the Fusarium genus are commonly isolated from soybean plants and seeds but not all of them are pathogenic. The aim of this study was to compare the pathogenicity among different Fusarium isolates obtained from soybean plants with disease symptoms originating from an experimental field located in the southeast of Poland. Nineteen fungal isolates were selected for the pathogenicity assay, including eight isolates of F. oxysporum, six isolates of F. graminearum, four isolates of F. culmorum and one isolate of F. redolens. Species identification of these isolates was carried out using microscopic methods and sequencing of two genes: translation elongation factor 1-alpha (TEF1) and RNA polymerase second largest subunit (RPB2). To our knowledge, this is the first report of F. redolens being isolated from soybean in Europe. The pathogenicity test was set up by fungal inoculation of healthy soybean seeds of three cultivars: Abelina, Atlanta and Mavka. Symptoms were assessed seven days after inoculation. Disease area percentage of Fusarium inoculated seeds was significantly higher compared to uninoculated control. Nineteen isolates differed in their aggressiveness as the median disease area percentage ranged between 5.0 and 88.0% depending on isolate. The obtained isolates of four Fusarium species may be used in the future screening of soybean cultivars for resistance to these pathogens.

Post Reclamation Evaluation of Residual Hydrocarbons in Crude Oil Contaminated Soil Using Gas Chromatographic Techniques and Plant Growth Indices

The present study was undertaken to evaluate the post-reclamation of crude oil-contaminated soil using gas chromatographic technique and plant growth indices. Enrichment techniques, turbidometric test, plasmid curing test, classical identification method, gas chromatographic flame ionization detection technique and plant growth indices were carried out using standard procedures. The results indicated that 22 of the isolates were observed to have high pollutant degrading potentials (A600nm &gt; 0.3) due to their crude oil utilization ability. The results also indicated that isolates which were able to degrade crude oil belonged to genera Bacillus, Pseudomanas sp., Ochrobacterium sp. and Enterobacter sp. Moreso, the remediation percentages recorded were 98 %, 80 %, 21 % and 98 %, 78 % and 22 % for the respective crude oil pollution (3 %, 5 % and 10 %) for soil inoculated plasmid borne bacteria whereas soil inoculated with plasmid cured bacterial cultures had 65 %, 52 %, 11 % and 65 %, 50 % and 20 % degradation of the same concentration of the total petroleum hydrocarbon after 60 days for both Phaseolus vulgaris and Glycine max plant seeds, respectively. The remediation percentages in the uninoculated controls include 3 %, 5 %, 10 % and 12 %, 9 % and 5 % across the pollutions for both plant seeds. A significant (P &lt; 0.05) increase in the growth parameters of the leguminous plants like percentage germination, mean plant shoot length, mean plant root length, plant fresh weight and number of root nodules were seen more in the soil microcosms inoculated with plasmid-borne bacteria than microcosm inoculated with culture of plasmid cured bacteria across all crude oil dilutions. Crude oil had a dose-dependent negative effect on the mean bacterial counts of each of the polluted soil containing the two different plants. Thus, the study clearly suggests that the selected hydrocarbon bacterial degraders could be effectively exploited in the remediation of crude oil-polluted sites.

First report of Fusarium keratoplasticum causing strawberry root rot in Sinaloa, Mexico.

Strawberry (Fragaria × ananassa) is a fruit of economic importance for Mexico, occupying the third place in world production, with an approximate production of 861, 337 t (SIAP, 2021). In January 2021, in Culiacan, Sinaloa, Mexico (24°46'46″N; 107°27'04″ W), wilting symptoms (stunted growth, leaf yellowing and wilting, necrosis in vascular bundles, root rot and wilting) were observed on commercial strawberry crops, with an incidence of 5 to 10 %. Tissue samples from symptomatic roots were cut and disinfected with alcohol, sodium hypochlorite and sterile water, to later be plated on potato dextrose agar (PDA). Fifteen monosporic isolates were obtained by single-spore culturing (Hansen and Smith, 1932). Typical Fusarium spp. colonies were obtained from all root samples. On PDA the colonies were abundant with white aerial mycelium, hyphae were branched and septate, and light-yellow pigmentation was observed in the center of old cultures (Leslie and Summerell 2006). From 10-day-old cultures grown on carnation leaf agar medium, macroconidia were slightly curved, showing three marked septa, broad central cells, slightly tapered apices, foot-shaped basal cells and measured 59.6 - 73.4 (x̄ = 68.7) x 10.4 - 14.9 μm (x̄ = 13.6) (n = 40). The microconidia (n = 40) were thin-walled, hyaline, ovoid unicellular that measured 19.7 - 32.2 (x̄ = 26.6) x 8.8 - 11.8 μm (x̄ = 10.2). The translation elongation factor 1 alpha (EF1-α) gene (O'Donnell et al. 1998) was amplified by polymerase chain reaction and sequenced. Maximum likelihood analysis was carried out using the EF1-α sequence from the isolate FKTFRESCULSIN (GenBank accession no. OK491929) and other Neocosmospora and Fusarium species. Phylogenetic analysis revealed the isolate was Fusarium keratoplasticum (currently named Neocosmospora keratoplastica) belonging to the Fusarium solani species complex (FSSC). Pathogenicity tests were performed on strawberry plants (cultivar Camarosa) grown on autoclaved sandy loam soil mix. Twenty plants were inoculated by drenching with 20 ml of a conidial suspension (1 × 105 CFU/ml) in an isotonic saline solution of FKTFRESCULSIN grown on PDA. Ten uninoculated plants served as controls. Plants were maintained for 60 days under greenhouse conditions (25 to 30°C). The assay was conducted twice. Root and stem rot similar to that observed on the infected plants in the field was observed. No symptoms were observed on uninoculated control plants after 60 days. The pathogen was reisolated from necrotic tissue from all inoculated plants and identified as F. keratoplasticum by sequencing the partial EF1-α gene and based on its morphological characteristics, thus fulfilling Koch's postulates. To our knowledge, this is the first report of root rot and wilt of strawberry caused by F. keratoplasticum in Mexico; it also contributes knowledge to the scientific community, since there is little information about this pathogen causing damage to plants in the world. Strawberry is an important crop in Mexico, and the occurrence of this disease could threaten strawberry production.

Function of the endophytic fungus Acrophialophora jodhpurensis, methionine, and nitric oxide in wheat resistance induction against Fusarium graminearum via interplay of reactive oxygen species and iron

In this study, the effect of Acrophialophora jodhpurensis, methionine, and sodium nitroprusside (as a NO donor) in induction of resistance against Fusarium graminearum, as a hemibiotrophic phytopathogenic fungus causing wheat root and crown rot, was investigated in vivo. Also, the effect of A. jodhpurensis was investigated on the mycelial growth, spore germination and hyphal structures of F. graminearum in vitro. The obtained results showed that A. jodhpurensis reduced mycelial growth and spore germination of the pathogen. Also, the spores and hyphae of the pathogen were swollen and deformed in the presence of A. jodhpurensis. Wheat root colonization by A. jodhpurensis and foliar application of methionine and sodium nitroprusside reduced the disease severity of F. graminearum and increased the plant growth parameters, such as shoot and root weight compared to the controls. Application of A. jodhpurensis, methionine and sodium nitroprusside had a significant effect in induction of resistance against F. graminearum via increasing superoxide (O2⋅-), hydrogen peroxide (H2O2), iron ions, phenolic contents, induction of antioxidant enzymes such as catalase (CAT), guaiacol peroxidase (GPX), ascorbate peroxidase (APX) and superoxide dismutase (SOD) activities, membrane stability index (MSI) and relative water content (RWC) compared to the plants only inoculated with F. graminearum and uninoculated controls. Simultaneous application of A. jodhpurensis and sodium nitroprusside was more effective than simultaneous application of A. jodhpurensis and methionine. Also, simultaneous application of A. jodhpurensis, methionine and sodium nitroprusside treatments showed more effect on the plant growth parameters and resistance induction against the pathogen compared to the other treatments. Therefore, the combined A. jodhpurensis, methionine and sodium nitroprusside treatment can be used for increasing the plant growth parameters and protecting wheat plants against F. graminearum.

Application of candidate endophytic fungi isolated from extreme desert adapted trees to mitigate the adverse effects of drought stress on maize (Zea mays L.)

The survival of plants under adverse conditions in desert habitats is related to microbial interactions, which can be an innovative strategy for reducing the effects of drought stress in colonized plants. In this study, two endophytic fungi, Trichoderma harzianum, and Fusarium solani, were recovered from the roots of trees in desert regions of Iran. A greenhouse experiment with two fungal agents (control, T. harzianum, F. solani, and T. harzianum + F. solani) and drought (100, 75, and 50% water-holding capacity) was performed on maize (Zea mays L.). Findings indicate that increasing drought levels negatively affect maize plant growth and physiological traits. However, the symbiotic relationship between fungal endophytes and maize roots increased fresh and dry biomass, root/shoot ratio, leaf area, relative water content, and membrane stability index compared with their control counterparts. Maize plants inoculated with endophytic fungi had 52.07, 40, 33.03, and 55.62% higher total phenolic, proline and soluble sugar concentrations, respectively than uninoculated controls. Photosynthetic parameters, including chlorophyll and carotenoid pigments, chlorophyll fluorescence, and gas exchange, were improved in the endophyte-treated plants. However, with increasing drought stress, maize plants colonized with endophytes, electrolyte leakage, and sub-stomatal CO2 concentrations decreased by 28.93% and 47.62%, respectively, compared to endophyte-free plants. When plants were exposed to higher levels of drought stress, endophytes were more effective in improving most parameters, and inoculation of maize seedlings with a combination of endophytes isolated from plants in harsh regions was more effective in increasing their tolerance to drought stress than individual inoculation of each fungus.

Impact of the Interaction between Meloidogyne javanica and Fusarium oxysporum on the Okra Plantation

The development of diseases in cultivated crops depends on the complex interrelationship between the host, pathogen, and prevailing environmental conditions. The interaction between the root knot nematode Meloidogyne javanica and the fungus Fusarium oxysporum was studied for the okra cultivar Pusa Sawani. Sequential and simultaneous inoculation of the nematode and fungus was performed to observe the disease severity in the plants due to the individual and interactive effects of the tested nematode and fungus. The results indicated that plant growth was adversely affected in all cases where the plant was inoculated with M. javanica and F. oxysporum, compared to the uninoculated control. The study clearly showed that nematodes act as predisposing factors in the spread of secondary fungal pathogens.

First report of Fusarium oxysporum f. sp. lactucae Race 1 causing lettuce wilt in Northern Ireland.

In the UK, lettuce is produced both in the field and in greenhouses or polytunnels. In summer 2022, wilt symptoms were observed for the first time on lettuce (cv. Amica) grown in soil in part of a single 0.55 ha greenhouse in County Armagh, Northern Ireland (NI). Initial presentation of symptoms was stunting of plants, followed by wilting and yellowing of lower leaves in approx. 12% of the plants. Orange-brown discoloration of vascular tissue in the tap root of affected plants was also observed. To isolate the causal pathogen, sections (0.5 cm2) of symptomatic vascular tissue from 5 plants were surface sterilized in 70% ethanol for 45 s, washed twice in sterile water and placed on potato dextrose agar (PDA) amended with 20 µg mL-1 chlortetracycline. Plates were incubated at 20°C for 5 days and fungal colonies sub cultured onto PDA. Isolates from all five samples displayed morphology typical of Fusarium oxysporum and were cream to purple in colour with abundant microconidia and occasional macroconidia. DNA was extracted from 5 isolates and part of the translation elongation factor 1- α (EF1-α) gene amplified by PCR and sequenced as described by Taylor et al. (2016). All EF1-α sequences were identical (OQ241898) and matched with F. oxysporum f. sp. lactucae race 1 (MW316853.1, isolate 231274) and race 4 (MK059958.1, isolate IRE1) with 100% sequence identity using BLAST. Isolates were then identified as FOL race 1 (FOL1) using a race-specific PCR assay (Pasquali et al. 2007). Next, pathogenicity and race identity of one isolate (AJ773) was confirmed using a set of differential lettuce cultivars (Gilardi et al. 2017); Costa Rica No. 4 (CR; FOL1 resistant), Banchu Red Fire (BRF; FOL4 resistant) and Gisela (GI; FOL1 / FOL4 susceptible). Plants were inoculated with AJ773 (this study), ATCCMya-3040 (FOL1, Italy; Gilardi et al. 2017) and LANCS1 (FOL4, UK; Taylor et al., 2019). Roots of 16-day-old lettuce plants (8 replicates per cultivar/isolate) were trimmed and soaked in a spore suspension (1 x 106 conidia mL-1) for 10 min before transplanting into compost in 9 cm pots. Control plants for each cultivar were dipped in sterile water. Pots were placed in a glasshouse (25C day, 18C night). Inoculation with AJ773 and FOL1 ATCCMya-3040 resulted in typical symptoms of Fusarium wilt for BRF and GI 12-15 days after inoculation, while for FOL4 LANCS1, wilting was observed in CR and GI. Thirty-two days after inoculation, plants were cut longitudinally and vascular browning was observed in all plants where wilt was present. All uninoculated control plants, CR inoculated with FOL1 ATCCMya-3040 or AJ773, and BRF inoculated with FOL4 LANCS1 remained healthy. These results confirm the identity of isolate AJ773 from NI as FOL1. Koch's postulates were fulfilled by consistent re-isolation of F. oxysporum from BRF and GI plants and identifying as FOL1 using the race-specific PCR. No FOL was re-isolated from control plants of any cultivar. Fusarium wilt in England and the Republic of Ireland first reported by Taylor et al. (2019) was identified as FOL4 and has been confined to indoor lettuce production with further outbreaks caused by the same race. However, FOL1 was recently identified in Norway in a soil-grown glasshouse crop (Herrero et al. 2021). The presence of both FOL1 and FOL4 in neighbouring countries within the UK is a serious risk to lettuce production and is of particular importance to growers who rely on knowledge of cultivar resistance to specific FOL races to make decisions on which variety to plant.