Phaseolina Research Articles

Advancing sustainable agriculture: Metal-doped urea–hydroxyapatite hybrid nanofertilizer for agro-industry

Abstract Nanotechnology holds excessive potential for addressing agricultural challenges such as soil deprivation, nutrient deficiencies, low harvests, and nutrient leaching. Nanofertilizers enable more efficient nutrient absorption by plants due to their enlarged surface area, bestowing viable solutions. Urea–hydroxyapatite hybrid (urea–HA hybrid) was successfully synthesized via a coprecipitation approach by doping nanohydroxyapatite with copper and zinc along with urea. The synthesized nanohybrids were analyzed by applying various techniques such as Fourier transform infrared spectroscopy, energy-dispersive spectroscopy (EDS), scanning electron microscopy, and X-ray powder diffraction (XRD). The evidence for the crystalline structure of HA was confirmed by peaks present in XRD analysis at 25.89°, 28.77°, and 32.11°, while urea was validated at 39.29°. The nanosized HA hexagonal nanorods were approximately 16 ± 1.5 nm, with the incorporation of urea, Cu, and Zn. The components of urea–HA hybrid (Ca, P, C, O, and N) were confirmed by EDS analysis with traces of Si. Antibacterial and antifungal activities were investigated against phytopathogenic microbes. The nanohybrid significantly inhibits the growth of Clavibacter michiganensis, Xanthomonas campestris, Macrophomina phaseolina, and Sclerotium rolfsii. A fertilization trial using urea–HA hybrid on Citrus limon has demonstrated a growth of 30 cm within 8 weeks of treatment, accompanied by brighter-colored leaves. Thus, the synthesized urea–HA hybrid enabled the slow release of nutrients, which had a significant impact on plant growth and will also effectively manage disease control against phytopathogens. Thus, this innovative approach addresses agricultural challenges regarding nutrient delivery and disease control more effectively.

Characterization and Pathogenicity of Soilborne Pathogens in Gloriosa superba: Effects of Single- and Multiple-Pathogen Coinfection on Disease Responses.

Glory lily (Gloriosa superba), an ornamental climbing plant, contains the bioactive compound colchicine, attracting attention from the pharmaceutical industry. However, soilborne pathogens have emerged as a serious threat to the cultivation of glory lily, leading to substantial economic losses in the southern parts of India. Among these, the three major pathogens are Macrophomina phaseolina, Fusarium oxysporum, and Agroathelia rolfsii, causing dry root rot (also referred to as charcoal rot), wilt, and stem rot, respectively. Here, we characterized these pathogens using morphological characteristics and phylogenetic analysis of DNA sequences related to the internal transcribed spacer of ribosomal DNA, calmodulin (CAL), and translation elongation factor 1-alpha (TEF-1α). Furthermore, in the pathogenicity tests, the inoculation of M. phaseolina alone resulted in lesions measuring 7.54 ± 0.01 mm on tubers and 90% seedling mortality. This severity was comparable to the simultaneous inoculation of all three pathogens, indicating the prominence of dry root rot among soilborne diseases. This study marks the first detailed investigation of soilborne pathogens combined infection in G. superba, contributing to the understanding of fungal disease complexity in medicinal plants.

A new species of Pythium hydnosporum as a pathogen associated with vine decline of melon (Cucumis melo L.) in Iraq

Several pathogenic fungi have become an important vine decline of cantaloupe melone (Cucumis melo L.). In 2021, root rot on cantaloupe was observed during the harvest phase in the fields in Penjwen and Shahrazoor in Sulaimani governorate of Northern Kurdistan region Iraq. This present study was conducted to isolate the causal agent of fungi in lesions of root rot of cantaloupe. A total of 16 fungal isolates were obtained of which isolates Monosporascus cannonballus, M. eutypoides, Acremonium vitellinium, Fusarium oxysporium, F. equiseti, Macrophomina phaseolina, Saccharomyces kudriavzevii, F. robinianum, Rhizopus arrhizus, Botrytis cinerea, Cytospora eucalypticola, F. falciforme, Pythium hydnosporum, Alternaria tenuissima, Rhizoctonia solani and Phytophthora colocasiae were obtained from root melon. Identification of all fungal isolates was based on using both morphological characteristics and molecular analysis, on internal transcribed spacer (ITS1, ITS4, LSU) are primers that are used for identification. DNA sequences of the fungal pathogen were identified as Pythium hydnosporum a new pathogenic fungi causal agent of cantaloupe vine decline. A pathogenicity test was conducted to verify Koch's postulates and P. hydnosporum was observed to cause root rot of melon, symptoms of the disease were similar to those seen in the field.

Phytopathological investigations of collar rot of chia (Salvia hispanica L.) caused by Macrophomina phaseolina – A new host record from India

Chia is an emerging medicinal and economically important crop cultivated in Karnataka, India. Characteristic collar rot symptoms were observed on chia during field investigations. The incidence was estimated and varied from 12 to 18 percent. Representative infected plant samples were collected and associated fungal pathogen was isolated (pure culture) on PDA medium. Morpho-cultural characterization of the fungal pathogen was identified as Macrophomina sp. Morphological identifications were supported by aetiology, cultural and microscopic observations. To confirm the identification, ITS-rDNA region and tub2 and tef-1α genes were amplified from genomic DNA of al selected samples and sequenced. The phylogenetic analysis was performed using concatenated sequence alignment of ITS-tub2-tef-1α. The nBLAST sequence analysis revealed that ITS region and tub2 and tef-1α genes sequence data shared maximum identity with known and reference sequences. Phylogenetic analysis was also performed and confirmed the identity based on phylogeny. The identity of the associated pathogen was confirmed as Macrophomina phaseolina based on micromorphology, cultural characteristics and ITS-tub2-tef-1α sequence data and phylogeny. Further, pathogenicity test was conducted and tested isolate was pathogenic and caused disease within 5–8 days of post inoculation. Identity was confirmed after re-isolation of the associated pathogens. To the best of our knowledge, this is the first report of M. phaseolina associated with collar rot disease on chia from India.

Synergistic interactions of biocontrol agents and chemical fungicides enhance the disease resistance in Vigna radiata (L.) against Macrophomina phaseolina-associated with dry root rot

Macrophomina phaseolina, a necrotrophic fungus responsible for dry root rot disease in Vigna radiata L. (greengram) causes extensive yield losses. Biocontrol agents are reported to suppress phytopathogens, mitigate biotic stress, and improve growth and yield of plants. Here, Bacillus subtilis PSB-5 and Trichoderma sp. TD-6 along with chemical fungicides; mancozeb (MZB) and carbendazim (CBZM) were evaluated alone/or in combination for their effectiveness against M. phaseolina-induced root rot disease in greengram. B. subtilis and Trichoderma sp. suppressed phyto-fungal growth by 72 and 78 %, respectively. Both bioagents synthesized indole-3-acetic acid, ammonia, and solubilized insoluble phosphate, released antimicrobial substances including siderophore, hydrogen cyanide, and various extracellular lytic enzymes. Further, efficacy of bioagents and fungicides (at 50 and 100 ppm) were tested (single and combined) against M. phaseolina-infected greengram cultivated in pot soils. While evaluating, bioagents and fungicides increased plant height, biomass, and vigor indices of infected greengram in order: PSB-5 + TD-6 > PSB-5 > TD-6 > MZB + CBZM (100 ppm) > CBZM (100 ppm) > MZB (100 ppm). Further, among treatment, dual inoculation of bioagents (B. subtilis + Trichoderma), maximally increased total chlorophyll (59.4 %), carotenoid (68 %), root phosphorous (69.6 %), root nitrogen (65.7 %), total soluble protein (80 %), soluble sugar (76 %), pod yield (82.3 %) and seed protein (68 %) over infected plants. Moreover, biotic stress-induced oxidative stress biomarkers (proline, malondialdehyde, electrolyte leakage) and reactive oxygen species were significantly (p ≤ 0.05) lowered in fungal-infected greengram following fungicides and bioagents application. Furthermore, combined inoculation of bioagents significantly (p ≤ 0.05) reduced percent disease index (PDI) and increased % protection in biotic-stressed greengram. Besides, bioagents potentially increased disease resistance in M. phaseolina-infected greengram plants by modulating defense responses such as activities of β-1, 3 glucanase, catalase, phenylalanine ammonia lyase, polyphenol oxidase, peroxidase, and superoxide dismutase which significantly protected plants from fungal pathogen. Soil populations of pathogen and bioagents declined and considerably increased, respectively, at harvest. Application of antagonistic bacterial and fungal strains enhances greengram resistance to M. phaseolina while concurrently offering agriculture an environmentally friendly choice. Also, these strains can be applied as biocontrol agents in disease suppression over chemical fungicides.

Multivariate approach applied to phenotypic traits as a function of the selection of soybean cultivars

The objective of this work was to identify superior soybean cultivars through a multivariate approach applied to phenotypic traits. This study was developed in the 2023/2024 agricultural harvest, in the experimental area of ​​the Regional Institute for Rural Development, at UNIJUÍ. It is located in the municipality of Augusto Pestana, in the state of Rio Grande do Sul, Brazil. The experimental design used was randomized blocks with internal blocks, with the treatment being ten cultivars and five replications. The trial of ten cultivars in the northwest of the state of Rio Grande do Sul demonstrated that the soybean cultivar with the highest yield was NS5922IPRO, with 5235.3 kg ha-1. The multivariate approaches formed two groups to explain the factors that influenced yield, where the first was discrepant for the variables Euschistus heros, phytotoxicity, Fusarium solanie, Macrophomina phaseolina, Conyza bonariensis, production zone area, number of total nodes in the branch, branch number, root length, number of vegetables with 4 grains, number of vegetables with 0 grains and vegetable grain weight of 2 grains. The second similar group for the variables Diabrotica speciosa, Caliothrips brasiliensis, Euschisthus heros, Phakopsora pachyrhizi and Cercospora sojina, area of ​​production zone, number of vegetables with zero grains. The trial of ten cultivars in the northwest of the state of Rio Grande do Sul demonstrated that the soybean cultivar with the highest yield was NS5922IPRO, with 5235.3 kg ha-1. The multivariate approaches formed two groups to explain the factors that influenced grain yield.

Chitosan-mediated copper nanohybrid attenuates the virulence of a necrotrophic fungal pathogen Macrophomina phaseolina.

This study reported the synthesis and characterization of chitosan-copper nanoparticles (Ch-CuNPs) using a 1% copper sulfate solution in 0.2% w/v chitosan. The Ch-CuNPs, displaying a stable brick-red hue, showed an absorption peak at 572nm, indicative of monodisperse nanoparticle formation and surface plasmon resonance. X-ray diffraction confirmed the face-centered cubic structure with peaks at 36.78°, 43.38°, 50.56°, and 74.26°, and an average particle size of 87-89nm. FTIR analysis showed interactions between chitosan and copper, particularly around 3370 -3226cm⁻¹, 1633cm⁻¹, and 680cm⁻¹. In vitro assays revealed that Ch-CuNPs inhibited Macrophomina phaseolina growth by 18-71% at 0.03-0.09% concentrations, achieving complete inhibition at 0.12-0.15%, with PCA analysis confirming that growth peaked at lower concentrations and sharply declined at higher levels. Ch-CuNPs also altered fungal morphology and enzyme activity, with notable degradation at higher concentrations. The Cu uptake by the fungus peaked at 29.9% with 0.03% Ch-CuNPs and decreased at higher concentrations. FTIR analysis showed shifts and disappearance of peaks in fungal biomass treated with Ch-CuNPs, indicating molecular interactions and potential structural changes. This study underscores the potential of Ch-CuNPs as an effective antifungal agent and elucidates their interaction mechanisms.

Study on effect of plant growth promoting rhizobacteria on sorghum (Sorghum bicolor L.) under gnotobiotic conditions

The rhizosphere is enriched with diverse microflora, allowing for delving prospective microorganisms to enhance crop growth and yield for varied soil conditions. Demand for millet growth-promoting microorganisms is a contemporary need for dryland agriculture. Therefore, a detailed survey was conducted in northern Karnataka, India, to identify the millet growing areas, particularly sorghum. The rhizobacteria from the sorghum (Sorghum bicolor L.) were assessed for promoting seed germination using the paper towel method and classified based on their efficiency. The elite isolates were positive for indole-3-acetic acid (IAA), gibberellic acid (GA), phosphate, zinc oxide solubilization, and hydrogen cyanide (HCN) production. The test isolates were antagonistic to Macrophomina phaseolina and Fusarium sp. and inhibited completely. Further evaluation of the cultures on sorghum growth-promoting attributes under pot culture conditions showed that the plants inoculated with PG-152 (Bacillus subtilis) recorded the highest plant height, chlorophyll content, root dry weight, shoot dry weight, and total dry weight under ideal conditions of fertilization. Two isolates, namely, PG-152 and PG-197, performing superior under pot culture conditions, were identified as Bacillus subtilis and PG-197 as Enterobacter sp., respectively, using 16S rDNA analysis. The sequences were allowed to screen open reading frames (ORF) and found several ORFs in Enterobacter cloacae and Bacillus subtilis, respectively. This study found that the rhizosphere is vital for identifying prospective isolates for biocontrol and plant growth-improving microorganisms.

Brassica juncea pre-season cover crops reduce soybean root colonization by Macrophomina phaseolina, the fungus causing charcoal rot

Macrophomina phaseolina (Tassi) Goid. is a soilborne fungus that causes charcoal rot in numerous crop plants, reducing yield and profits. This study assessed the efficacy of pre-season mustard cover crops (Brassica juncea), a chemical fungicide seed treatment, a combination of both, and a non-treated control in a set of varieties that ranged in maturity. In 2016 and 2017, 'AG4135 RR2Y/SR' consistently yielded lower compared to other varieties. Early maturity varieties exhibited reduced yields relative to mid and late maturity pairs in 2016 and 2017. Root colonization was influenced by treatment, with the combined pre-season cover crop and seed treatment exhibiting the lowest colonization rates in 2015, while all treatments had significantly reduced colonization in 2017 compared to untreated controls. Additionally, differences in root colonization were observed among soybean varieties, suggesting genotype-specific responses to disease management strategies. M. phaseolina soil populations showed a marked increase from pre-cover crop to post-soybean harvest underscoring the pathogen's proliferation throughout the growing season. Correlation analyses revealed significant negative relationships between root colonization and yield for untreated controls, suggesting that higher root colonization adversely affected crop performance. These findings suggest that specific treatments may help mitigate M. phaseolina population build-up in roots and soil and indicate that the effectiveness of control measures may be influenced by pathogen variability in response to environmental conditions and management practices. These findings also contribute to our understanding of effective strategies for managing charcoal rot disease and highlights the importance of integrating chemical and biological control methods.

New binary mixtures of fungicides against Macrophomina phaseolina: Machine learning-driven QSAR, read-across prediction, and molecular dynamics simulation

Quantitative Structure-Activity Relationship (QSAR) analysis greatly enhances the development and research of pesticides. This study employed Multiple Linear Regression (MLR), machine learning (ML), and read-across (RA) approaches to investigate the combined effects of binary mixtures of fungicides on Macrophomina phaseolina. Using the Fixed Ratio Ray Design (FRRD) method, 75 binary mixtures of six frequently used fungicides were generated, with many exhibiting additive interactions as indicated by the Concentration Addition (CA) and Independent Action (IA) models. The QSAR analysis revealed that Support Vector Regression (SVR) and Gaussian Process Regression (GPR) models were the most effective, outperforming the Least Squares Kernel (LSK), MLR, and RA methods. SVR achieved an outstanding R2 of 0.95 and Q2LMO of 0.81, whereas GPR demonstrated values of 0.93 and 0.81 for the same metrics. Internal and external validation confirmed the reliability and generalizability of these models, suggesting they could be applied to a wider array of data. Moreover, Molecular Dynamics (MD) simulations showed that the effects of the fungicides are linked to physiological mechanisms rather than intermolecular interactions within their formulations. This study establishes a robust framework for creating potent fungicide combinations that improve disease management efficacy while promoting environmental sustainability and reducing the chemical load to mitigate negative impacts.

Cover cropping attenuates population growth of Macrophomina phaseolina by limiting weed biomass, despite asymptomatic colonization of cover crops.

Macrophomina phaseolina is a fungus that causes charcoal rot in strawberry and a wide variety of crop species. Little is known about its potential to asymptomatically colonize crop plants or grow saprophytically on their tissues, both of which would create a potential for alternate, asymptomatic hosts to lead to increases in inoculum. To test the impact of cover cropping on M. phaseolina abundance, we conducted randomized-block field experiments in soils infested by M. phaseolina. None of the fifteen cover crop varieties showed symptoms of charcoal rot. All Fabaceae and Brassicaceae varieties were asymptomatically colonized at varying rates, but among Poaceae, M. phaseolina was recovered from only one individual oat plant. Soil samples collected at the time of planting, tillage, and 8 weeks post-tillage showed that cover cropping attenuated the growth of M. phaseolina relative to fallow plots harboring the weedy legume Medicago polymorpha. This weed species was abundantly colonized by this pathogen in both living root samples and plant residue collected 8 weeks after tillage. Cover cropping also influenced the diversity and composition of bulk soil bacterial and fungal communities, but these effects were not associated with M. phaseolina population density. Although M. phaseolina was not detected in living wheat tissues, it was recovered from wheat residue, suggesting that it may be facultatively saprophytic. These results suggest that cover cropping does not pose a risk for increasing disease caused by M. phaseolina and could be beneficial as conducive weed species, such as M. polymorpha, are suppressed.

Unveiling the Hidden Enemies: Morphological and Molecular Characterization of Pod Rot Pathogens in Groundnut (Arachis hypogea L.) in India

Pod rot of groundnut is a complex disease caused by multiple pathogens causes significant economic losses. Present study was undertaken to know the pathogens associated with the disease. In Chittoor, Andhra Pradesh, roving survey against pod rot of groundnut revealed association of three fungal species: Sclerotium rolfsii, Rhizoctonia bataticola and Fusarium spp. Molecular analysis with modified CTAB method and performing PCR using ITS1 and ITS4 primers yielded DNA bands of 650-700 bp, 550-600 bp, and 500-600 bp for Sclerotium, Rhizoctonia and Fusarium species, respectively. Sequencing of the rDNA ITS region confirmed the identities of the pathogens as Sclerotium rolfsii, Rhizoctonia bataticola, Fusarium solani, Fusarium oxysporum, and Fusarium keratoplasticum, based on similarity with NCBI reference sequences. This study confirms that Sclerotium rolfsii, Rhizoctonia bataticola and Fusarium spp. are the primary causal agents of pod rot disease in Andhra Pradesh.

Enhancing Growth in Vigna radiata through the Inhibition of Charcoal Rot Disease: A Strategic Approach Using Plant Growth-Promoting Rhizobacteria.

Macrophomina phaseolina is a vital seed and soil-borne phytopathogen responsible for substantial crop yield losses. Although various methods exist for managing soil-borne pathogens, such as agronomic practices, chemical treatments, and varietal tolerance, biological control utilizing plant growth-promoting rhizobacteria (PGPR) or their secondary metabolites presents promising avenues. In this study, a screening of 150 isolates from the rhizosphere of Vigna radiata L. was conducted to identify strains capable of promoting host growth and controlling charcoal rot disease. Among the tested isolates, only 15 strains demonstrated the ability to produce plant growth-related metabolites, including indole acetic acid, hydrogen cyanide, ammonia, and lytic enzymes, and solubilize inorganic phosphate. Subsequently, these potent strains were evaluated for their antifungal activity against Macrophomina phaseolina in vitro. Three strains, namely MRP-7 (58% growth inhibition), MRP-12 (55% growth inhibition), and MRP-8 (44% growth inhibition), exhibited the highest percent growth inhibition (PGI.). Furthermore, a pot experiment demonstrated that the selected strains acted as effective growth promoters and ROS (reactive oxygen species) scavengers, and served as potential biocontrol agents, significantly reducing the incidence of charcoal rot disease and improving various agronomic attributes of the host plant. These findings highlight the potential of these strains to be utilized as biofertilizers and biocontrol agents for sustainable agricultural practices.

Marker-assisted Pyramiding of Charcoal Rot Resistance Loci in Strawberry

Macrophomina phaseolina, the causal agent of charcoal rot, is one of the most destructive soil-borne pathogens that affect the global strawberry industry. Resistant cultivars are critical for ensuring the profitability of strawberry production without the protection historically provided by methyl bromide. Previously, three loci, namely, FaRMp1, FaRMp2, and FaRMp3, associated with quantitative resistance to Macrophomina phaseolina have been identified and validated across diverse populations and environments. Among those, the locus with the largest effect, FaRMp3, was initially detected in crosses with an exotic Fragaria ×ananassa selection. We introgressed the favorable FaRMp3 allele into elite germplasm in the University of Florida strawberry breeding program already segregating for FaRMp1 and FaRMp2 and confirmed its phenotypic effects across various genetic backgrounds. Subsequently, we developed a high-throughput genotyping assay to facilitate the transfer and selection of FaRMp3 in breeding populations via marker-assisted selection. Given that three quantitative trait loci (QTL) contribute to partial resistance to Macrophomina phaseolina, stacking them within a single genotype presents a potential strategy for enhancing resistance. We screened 564 individuals that segregate for favorable alleles at all three QTL to assess their effects singly and in combination across multiple genetic backgrounds and production seasons. Inoculated field trials revealed that the three QTL cumulatively enhanced resistance levels, and that two-way QTL combinations including FaRMp3 provide increased protection against the pathogen. Pyramiding all three loci achieved the strongest resistance and could provide substantial economic value to the strawberry industry.

Efficacy of different fungicides against Rhizoctonia bataticola causing Soybean root rot

Efficacy of different fungicides against Rhizoctonia bataticola causing Soybean root rot

In-vitro efficacy of fungicides against Rhizoctonia bataticola causing black gram root rot

In-vitro efficacy of fungicides against Rhizoctonia bataticola causing black gram root rot

Morphological and molecular characterization of Macrophomina phaseolina (Tassi) Goid isolates causing charcoal rot of cowpea (Vigna unguiculata (L.) Walp) in Ghana

The study of the variations in Macrophomina phaseolina, the causal agent of charcoal rot, is critical in understanding the ecology of the isolates and the epidemiology of the diseases they cause. This study sought to identify and characterize M. phaseolina isolates using both molecular and morphological approaches and to determine the virulence of the isolates. Macrophomina phaseolina was isolated from cowpea-diseased stem tissues. Eleven M. phaseolina isolates from the major cowpea growing areas (Manga, Nyankpala, Yendi, Damongo, Tumu, Wa, Akomadan and Ejura) were morphologically and molecularly characterized. DNA of the M. phaseolina isolates were amplified using species-specific PCR primers MpKF1 (5'-CCGCCAGAGGACTATCAAAC-3') and MpKR1 (5'-CGTCCGAAGCGAGGTGTATT-3') and sequencing of the M. phaseolina specific amplicons was obtained. This was followed by searching against the NCBI nucleotide sequence database. Isolates were tested for their pathogenicity on a susceptible cowpea cultivar (IT97K-499-35). Virulence of the M. phaseolina isolates was expressed as the percentage of sown seeds that expressed seed rot and damping-off symptoms 14 days after planting. All isolates were confirmed as M. phaseolina based on the amplicon size obtained, and the sequenced amplicons showed an average of 99% homology to the available M. phaseolina sequences. The radial growth of isolates and the percentage of seed rot and damping off they caused on the IT97K-499-35 cultivar varied significantly. The percentage seed rot and damping off were positively correlated (r = 0.74 and 0.75) with the radial growth and colour intensity of the isolates, respectively. Macrophomina phaseolina infection and disease expression may be predicted by the colour and colour intensity of isolates as well as cowpea genotypes. Isolate Mp_3Mc (dense black colour) was the most virulent while isolate Mp_6Ec (grey colour) was the least virulent, resulting in 76.7% and 26.7% seed rot and damping off, respectively. The three clades resolved through the phylogenetic tree matched the distinct colour types of M. phaseolina which correlated with virulence. Isolates of M. phaseolina are diverse and differ in their pathogenicity. Efforts must be geared towards developing cowpea varieties that have resistance to charcoal rot disease.

Bio-Efficacy of Seed Dressing Fungicide Carbendazim 12% + Mancozeb 63% WP against Important Fungal Diseases of Groundnut

Groundnut is an important legume and oil seed crop and oil seed crop in world, which is prone to many soil borne diseases viz., Collar rot (Aspergillus niger), Dry root rot (Macrophomina phaseolina) and foliar disease like tikka leaf spot (Cercospora arachidicola) causes major economic losses in yield. The field experiment was conducted on bio efficacy of carbendazim 12% + mancozeb 63% WP as a seed treatment against collar rot, dry root rot and tikka leaf spot in groundnut at college of Sericulture, Chintamani during Kharif 2019-20. The seed treatment of Carbendazim 12% + Mancozeb 63% WP @ 3.0 g/kg of seeds treated plot recorded 95.17% seed germination with minimum early leaf spot, (PDI 7.18) dry root rot incidence (2.20%) and collar rot incidence (1.98%) having highest pod yield of 27.23 q/ha and fodder yield of 41.72 q/ha with cost to benefit ratio of 1:4.05 which was on par with Carbendazim 12% + Mancozeb 63% WP @ 2.5 g /kg of seeds treated plot with 94.17% seed germination with least severity of early leaf spot (PDI 8.22), dry root rot (2.42%) and collar rot (2.18%) incidence having pod yield of 26.90 q/ha and fodder yield of 41.13 q/ha with cost to benefit ratio of 1:4.01.

Pyrolysed maize feedstock utilization in combination with Trichoderma viride against Macrophomina phaseolina

Maize cultivation is under the growing threat of charcoal rot (Macrophomina phaseolina). Chemical control of diseases imparts serious health hazards to humans and the ecosystem. Biochar as an alternative disease management approach has been under consideration of the researchers for some time now. The biochar utilized in this study was derived from maize stalks and cobs. Crystallographic structure, inorganic minerals content and size of maize biochar were analyzed by powder X-ray diffractometer, while scanning electron microscopy revealed rough, irregular, tubular structure of the biochar surface. EDX spectra revealed that the maize biochar composition was dominated by ‘C’ followed by ‘O’. The current study was designed to determine the synergistic effect of maize biochar (MB), and biocontrol agent (BCA) Trichoderma viride as soil amendments on the suppression of M. phaseolina. In vitro bioassays were conducted to check the efficiency of antagonistic effect of Trichoderma spp., in combination with maize biochar. On the basis of maximum mycelial growth inhibition T. viride was selected for a glasshouse experiment. Maize plants were grown in pots containing a mixture of soil with MB at application at the rate of 3 and 6% (v/v) separately, associated with or without T. viride. Treatments amended with 3% MB inoculated with M. phaseolina significantly reduced the percentage disease severity index by 40%. While in the presence of T. viride, 3% MB showed maximum disease suppression and a minimum percentage severity index i.e. 60 and 20%, respectively. Highest nitrogen contents were 18.4 g kg−1 observed in treatment 6% MB, while highest phosphorus and potassium contents were 3.11 and 15.2 g kg−1, respectively in the treatment with 3% MB. Conclusively, the effect of variable concentrations of maize biochar and T. viride as soil amendment was evident on the development of charcoal rot, growth and physiology of maize plants. According to the available literature, our report is the first on the implementation of biochar in synergism with T. viride to suppress the charcoal rot in maize.

Tuber pathogenicity of Macrophomina phaseolina strain 3a isolated from rotten cassava tuber from farm lands in Osogbo, Osun State, Nigeria, its virulence genes and ADMET properties.

Macrophomina phaseolina is a pathogen that causes an opportunistic disease that spreads by soil and seeds and affects more than 500 different plant species, like fruits, trees, and row crops. Mycotoxins, such as phaseolinic acid, and phaseolinone, are produced by M. phaseolina isolates in previous investigations; however, the production of these mycotoxins seems to vary depending on the host and the region. In this study, Macrophomina phaseolina strain 3A was isolated from rotten cassava tuber and identified using the analysis of the sequences of the internal transcribed spacer region. The isolate was inoculated on a fresh healthy cassava tuber at 25°C and tuber-rotting potential was monitored for 4 weeks. Virulence genes MPH_06603, MPH_06955, and MPH_01521 were determined with designed primers, and secondary metabolites were characterized by FTIR and GCMS. The rotten tuber effect was observed from the 2nd week of the experiment with severe tuber rot and weight reduction. The PCR showed the presence of MPH_06603 virulence gene. The GCMS showed N-Methylpivalamide (115.0m/z), Butane, 1,4-dimethoxy- (119.0m/z), and 5-Hydroxymethylfurfural (126.0m/z) were the predominant metabolites produced by the pathogen. The compounds in the metabolites inhibit CYP3A4 enzymes, cause eye irritation, and Human Ether-a-go-go-related gene inhibition. This study revealed that M. phaseolina was responsible for the cassava tuber rot which leads to a lower yield of farm produce. The metabolites produced are toxic and unsafe for human consumption. It is suggested that farmers should destroy any cassava affected by this pathogen to prevent its toxic effects on humans and animals.