Alternaria Solani Research Articles

Comparative study of endophytic bacterial strains from non-host crops for enhancing plant growth and managing early blight in tomato

Bacillus pseudomycoides, Paenibacillus polymyxa, and B. velezensis are potent bacterial endophytes, which typically exhibit host-specific interactions. However, comparative studies of these endophytes in vitro and in planta in non-host crops are lacking. Therefore, in this study, we evaluated the potential of endophytes B. pseudomycoides strain HP3d, P. polymyxa strain PGSS1, B. velezensis strain A6, and P42, isolated from various crop ecosystems in promoting plant growth and inducing systemic resistance against early blight disease in tomato. In vitro, endophytes exhibited 44.44–55.56% and 37.50–87.50% inhibition of Alternaria solani in dual culture and volatilome bioassay, respectively. In the glasshouse, individual and combined applications via seed treatment (ST), seedling dip (SD), and foliar spray (FS) significantly enhanced shoot growth (23.63–57.61%), root growth (43.27–118.23%), number of leaves (77.52–93.58%), number of shoots (33.42–45.28%) and root dry matter (42.17–43.86%), reducing early blight (PDI) by 70.95–76.12% compared to uninoculated control. Enzymatic activities, including such as polyphenol oxidase (30–40 fold), peroxidase (65.00–75.00 fold), superoxide dismutase (34.20–37.20 fold) and phenylalanine ammonia-lyase (44.44–45.56 fold) were elevated post-inoculation in endophytes treated tomato plants challenged with A. solani compared to control treated only with A. solani and declined after the fifth day. The total chlorophyll content declined from the 0th to the 10th day, but endophyte treated plants exhibited lesser reductions (2.03–2.09) than uninoculated control. Field trials confirmed the glasshouse findings, showing reduced early blight and improved growth parameters in tomato where the ST + SD + FS combination emerged as the most effective treatment for all endophytes showing 1.06–1.88 fold increase in fruit yield per plant and 28.92–32.52% decrease in PDI compared to untreated control. Thus, the study highlights the broad-spectrum potential of these strains in promoting plant growth and controlling early blight in tomato, demonstrating non-host specificity. These endophytes offer eco-friendly alternatives to chemical pesticides, supporting sustainable agriculture. Their success in field trials suggests the potential for commercialization and large-scale use across diverse crops and pave the way for further interdisciplinary research to optimize their application in integrated pest management strategies.

Compatibility and antimicrobial activity of silver nanoparticles synthesized using Lycopersicon esculentum peels.

Nanoparticles have gained worldwide attention as a new alternative to chemical control agents due to their special physiochemical properties. The current study focused on the environmentally friendly synthesis of silver nanoparticles (AgNPs) using Lycopersicon esculentum peel. In addition to studying the intrinsic cytotoxic effectiveness of Le-AgNPs contribute to their antibacterial, and antifungal activities and the effect of nanoparticles on the integrity of their morphological behavior. The initiative biosynthesis of L. esculentum silver nanoparticles (Le-AgNPs) was indicated by the color change of L. esculentum (Le) extract mixed with silver nitrate (AgNO3) solution from faint pink to faint brown. UV-visible spectroscopy, Dynamic light scattering (DLS), Fourier-transform infrared spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and X-ray diffraction techniques were used to characterize biosynthesized Le-AgNPs. Results of UV-visible spectroscopy recorded surface plasmon resonance at 310nm for SPR of 2.5. The DLS results showed particles of 186nm with a polydispersity index of 0.573. The FTIR spectrum indicated the existence of carboxyl, hydroxyl, phenolic, and amide functional groups. The HR-TEM analysis revealed quasi-spherical crystal particles of Le-AgNPs. Le-AgNPs had a negative zeta potential of - 68.44mV, indicating high stability. Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 8739 were the most susceptible pathogens to Le-AgNPs inhibition, with inhibition zone diameters (IZDs) of 4.0 and 0.92cm, respectively. However, Listeria monocytogenes NC 013768 and Shigella sonnei DSM 5570 were the most resistant pathogens, with IZDs of 0.92 and 0.90cm, respectively. Le-AgNPs demonstrated good inhibitory potential against pathogenic fungi, with IZDs of 3.0 and 0.92cm against Alternaria solani ATCC 62102 and Candida albicans DSM 1386, respectively. The cytotoxicity effect was observed at a half-maximal inhibitory concentration (IC50) of 200.53μg/ml on human colon NCM460D normal cells.

Effectiveness of plant extracts against Alternaria leaf blight (Alternaria alternata) infecting tomato

Tomato (Lycopersicon esculentum Mill.) is one of the most remunerative and widely grown vegetables in the world. This crop is affected by major fungal pathogens (viz., early blight, late blight, wilt, collar rot, damping off and powdery mildew), among them early blight (Alternaria alternata) is considered as most important one. Among the phyto-extracts tested, the majority were found effective in inhibiting the radial growth of test fungus and highest inhibition was in neem, garlic and turmeric extracts at 10 % concentration which recorded 80.86, 79.34 and 75.24 % inhibition, respectively.

Effectiveness of systemic fungicides against tomato early blight (Alternaria alternata)

Tomato (Lycopersicon esculentum Mill.) is one of the most remunerative and widely grown vegetables in the world. This crop is affected by major fungal pathogens (viz., early blight, late blight, wilt, collar rot, damping off and powdery mildew), among them early blight (Alternaria alternata) is considered as most important one. Among the fungicide tested, the majority were found effective in inhibiting the radial growth of test fungus and highest inhibition was observed in propiconazole 25 EC at 250 and 500 ppm concentration; difenoconazole 25 EC and tebuconazole 25.9 EC at 500 ppm concentration which were equally effective and completely inhibited the mycelial growth and proved significantly superior over rest of the treatments.

Modification of chitosan-ethyl formate polymer with zinc oxide nanoparticles and β-CD to minimize the harmful effects of Alternaria early blight on Vicia faba

Derivatives of chitosan-ethyl formate polymers (Chs-EF) show promise as biologically relevant materials. The novelty of this study lies in the innovative use of Chs-EF doped with zinc oxide nanoparticles and beta-cyclodextrin, which significantly enhances the polymers' protective activities against Alternaria early blight disease in Vicia faba by improving both disease resistance and plant health. After doping Chs-EF with zinc oxide nanoparticles (ZnONPs) and inserting it into the beta-cyclodextrin (CD), two products emerged: Chs-EF/ZnONPs and Chs-EF/CD. Using βCD and ZnONPs to modify the Chs-EF polymer improves the optical properties of the generated polymers. Also, the energy gab values of the modified polymers (Chs-EF/ZnONPs and Chs-EF/βCD) were 3.3 and 3.7 eV, respectively, while energy gab value of the Chs-EF polymer was 3.9 eV. In this study, the effects of ZnONPs, chitosan, β-CD, and Chs-EF/ZnONPs on Alternaria solani early blight disease in Vicia faba plants were investigated. The treatments were evaluated based on disease symptoms and a disease index (DI) to assess their ability to protect against Alternaria early blight disease blight. The results show that the modified polymer with ZnONPs and beta-cyclodextrin (β-CD) and the modified polymer with ZnONPs (Chs-EF/ZnO NPs) provided the best protection, with DI values of 25 % and 12.5 %, respectively. Furthermore, it was discovered that the levels of carotenoids, chlorophyll a, and chlorophyll b in the infected plants had dropped by 52.6 %, 69.2 %, and 36.1 %, respectively. Chs-EF/ZnONPs were the most effective treatment, showing significant increases in the contents of chlorophyll a and b in infected plants by 120.8 % and 225.4 %, respectively. The study revealed that Chs-EF/ZnONPs exhibited a 131 % increase in the total phenolic content of plants, peroxidase (POD) activity (110.6 %), and a 347 % increase in polyphenol oxidase (PPO) activity, respectively, compared to healthy plants. Malondialdhyde (MDA) decreased by 50.7 %, 49.7 %, 43.4 %, 36.6 %, 31.7 %, and 7.5 % in response to Chs-EF/ZnONPs, Chs-EF/β-CD, Chs-EF, ZnONPs, Chitosan, and β-CD, respectively. Also, application of Chs-EF/ZnONPs, Chs-EF/β-CD, Chs-EF, ZnONPs, Chitosan, and β-CD reduced the production of H2O2 by 77.5 %, 62.8 %, 62.5 %, 39.6 %, 22 %, and 15.1 %, respectively, compared to infected controls. We recommend considering these substances as promising candidates for agricultural use, as they may effectively serve as control agents against early blight caused by Alternaria solani.

Design, synthesis and antifungal activity of arylhydrazine analogs containing diphenyl ether fragments.

Succinate dehydrogenase (SDH) represents a critical target in the development of novel fungicides. To address the growing issue of resistance and safeguard the economic viability of agricultural production, the pursuit of new succinate dehydrogenase inhibitors (SDHIs) has emerged as a significant focus of contemporary research. In this project, 32 arylhydrazine derivatives containing diphenyl ether structural units were synthesized and evaluated for their fungicidal activities against Rhizoctonia solani, Sclerotinia sclerotiorum, Alternaria alternata, Gibberella zeae, Alternaria solani and Colletotrichum gloeosporioides. In an in vitro fungicidal activity assay, compound D6 showed significant inhibitory activity against R. solani with a half-maximum effective concentration (EC50) of 0.09 mg L-1. The in vivo fungicidal activity demonstrated that compound D6 inhibited R. solani by 95.39% in rice leaves, which was significantly better than that of boscalid (85.76%). The results of SDH enzyme assay, molecular docking simulation, mitochondrial membrane potential assay, cytoplasmic release studies and morphological observations demonstrated that the target compound D6 not only had significant SDH inhibitory activity, but also affected the membrane integrity of mycelium. Bioactivity screening and validation of the mechanism of action indicated that compound D6 was a potentially unique SDHI, acting on SDH while also affecting cell membrane permeability, which deserved further study. © 2024 Society of Chemical Industry.

Preliminary Insights into Sustainable Control of Solanum lycopersicum Early Blight: Harnessing Arbuscular Mycorrhizal Fungi and Reducing Fungicide Dose

Tomato (Solanum lycopersicum L.) production is constantly threatened by several fungal pathogens, such as Alternaria solani, the causal agent of early blight disease. In this study, a greenhouse experiment was set up to evaluate the biocontrol ability of arbuscular mycorrhizal fungi (AMF) against A. solani in the presence of reduced doses of fungicides (i.e., captan and copper oxychloride). Disease severity, plant growth traits, chlorophyll and phosphorus content, phenolic compounds, and antioxidant activity were assessed. The effects of fungicide dose on AMF were investigated by root colonization, spore density, and mycorrhizal dependence evaluation. AMF-inoculated and fungicide-treated plants reduced disease severity compared to fungicide-treated and non-mycorrhizal plants, in most cases, regardless of the fungicide dose. AMF improved plant growth, especially when combined with copper oxychloride. However, plant fresh weight decreased in plants treated with the lowest dose of captan (25 g 100 L−1). Overall, AMF colonization decreased in plants with high fungicide doses, while the leaf color parameters did not show differences between treatments. The results suggest reducing the fungicide dose using AMF is possible, particularly for copper oxychloride. Further studies will be required to confirm these data. This integrated approach could offer a sustainable alternative to decrease the use of chemical control.

Early Blight Disease Management of Potato

Early Blight Disease Management of Potato

Novel Aminocoumarin-Based Schiff Bases: High Antifungal Activity in Agriculture.

Structural modification is an effective way to improve the antifungal activity of natural products and has been widely used in the development of novel fungicides. In this work, a series of aminocoumarin-based Schiff bases were synthesized and characterized by 1H-NMR, 13C NMR and HR-MS spectra. The in vitro inhibition activity of all compounds was tested against four phytopathogenic fungi (Alternaria solani, Fusarium oxysporum, Botrytis cinerea, and Alternaria alternata) using the mycelial growth rate method. The results showed that most of the target compounds exhibited significant antifungal activities. In particular, compounds 5b, 5c, 5d, 5h, 5n, 7c, 7n, and 7p exhibited more effective antifungal activity than commercially available fungicides, chlorothalonil and azoxystrobin. The structure-activity relationship revealed that the electron-withdrawing groups with more electronegativity introduced at the C-3 position were effective in improving the inhibitory activity and that halogenated benzaldehydes would be necessary in the preparation of Schiff bases. The compound 5n against Fusarium oxysporum (EC50=8.73 μg/mL) and the compound 7p against Alternaria alternata (EC50=26.25 μg/mL) were much better than the positive controls (chlorothalonil and azoxystrobin). Therefore, compounds 5n and 7p could serve as promising lead compounds for the development of novel broad-spectrum fungicides, which could be useful for applications in the agriculture.

A CARS-SPA-GA Feature Wavelength Selection Method Based on Hyperspectral Imaging with Potato Leaf Disease Classification.

Early blight and ladybug beetle infestation are important factors threatening potato yields. The current research on disease classification using the spectral differences between the healthy and disease-stressed leaves of plants has achieved good progress in a variety of crops, but less research has been conducted on early blight in potato. This paper proposes a CARS-SPA-GA feature selection method. First, the raw spectral data of potato leaves in the visible/near-infrared light region were preprocessed. Then, the feature wavelengths were selected via competitive adaptive reweighted sampling (CARS) and the successive projection algorithm (SPA), respectively. Then, the two sets of wavelengths were reorganized and duplicates were removed, and secondary feature selection was conducted with genetic algorithm (GA). Finally, the feature wavelengths were fed into different classifiers and the parameters were optimized using a real-coded genetic algorithm (RCGA). The experimental results show that the feature wavelengths selected by the CARS-SPA-GA method accounted only for 9% of the full band, and the classification accuracy of the RCGA-optimized support vector machine (SVM) classification model reached 98.366%. These results show that it is feasible to classify early blight and ladybug beetle infestation in potato using visible/near-infrared spectral data, and the CARS-SPA-GA method can substantially improve the accuracy and detection efficiency of potato pest and disease classification.

Efficacy of Pleurotus ostreatus mycelia as bioinoculant to improve growth of pepper plant and protect against wilt causing Fusarium oxysporum

Among the different value added uses of mushroom, vegetative mycelia of Pleurotus ostreatus can be explored as a bio-inoculant for sustainable agriculture use. From three fruit-bodies of Pleurotus ostreatus, tissue cultures were established, were used for DNA preparation and biochemical tests. Phylogenetic analysis using three SSU-ITS-LSU markers indicated that the species Pleurotus ostreatus occupies a separate clade. Ability of the isolates to synthesis indole acetic acid (39.66–48.33 μg/ml), siderophore (hydroxamate and phenolate types) and enzymes like chitinase, protease and lipase had promoted us to apply them as bio-inoculant for plant growth promotion and against fungal pathogens. In dual culture assay, P. ostreatus isolates inhibited growth of Fusarium oxysporum SF1404 (44.4–66.5 % inhibition) and Alternaria solani TD3 (44.4–55.5 % inhibition). The mycelia culture of the fast-growing isolate (KUFC113) was applied on rhizosphere of pepper plant to protect against wilt causing F. oxysporum, and it was observed that the pathogen did not exhibit any wilting symptom. Assay of the stress enzymes (ascorbic acid peroxidase, catalase, peroxidase, and polyphenol oxidase), flavonoid, phenol content also supported that treatment of the mushroom culture could ameliorate the biotic stress in the plants. The mycelia of P. ostreatus colonized on the rhizosphere of pepper plant and influenced the growth by improving plant biomass, chlorophyll and metabolite contents. The principal component analysis and Pearson's correlation matrix showed correlation among the growth parameters of pepper plants.

Foliar blight, leaf spot, and stem blackening diseases caused by Stemphylium beticola, Alternaria alternata, and Alternaria atra on dragon's head (Lallemantia iberica) in Iran

Dragon's head, Lallemantia iberica, is an oilseed crop adapted to be grown in cold-dry areas. In the growing season of 2022–23 a severe foliar blight, leaf spot, and stem blacking symptoms were observed in commercial fields in northern and northwestern Iran, leading to more than 50 % yield loss. Infected samples were collected and transferred to the laboratory. Following the isolation of fungal agents, five representative isolates were selected for further studies. Morphological studies, based on conidial shape, conidiation, and other mycological characteristics, were carried out on a pure culture established from a single spore. Furthermore, multigene phylogenetic analyses were performed using sequences of translation elongation factor 1-α (TEF1), glyceraldehyde 3-phosphate dehydrogenase (GAPDH), RNA polymerase II second largest subunit (RPB2), and Internal Transcribed Spacer (ITS) rDNA genes for Alternaria isolates, along with calmodulin (cmdA) for the Stemphylium isolate. The morphological and molecular studies identified the fungal isolates as Alternaria atra, Alternaria alternata, and Stemphyliium beticola. Pathogenicity tests on the commercial cultivar ‘Sara’ indicated that all isolates were pathogenic to dragon's head, but they differed significantly in aggressiveness. To the best of our knowledge, this is the first report of the association of these fungal species with an important foliar disease on this crop in Iran and worldwide.

Investigating the antifungal potential of genetically modified hybrid chitinase enzymes derived from Bacillus subtilis and Serratia marcescens.

Chitinases are glycosyl hydrolase enzymes that break down chitin, an integral component of fungal cell walls. Bacteria such as Bacillus subtilis and Serratia marcescens produce chitinases with antifungal properties. In this study, we aimed to generate hybrid chitinase enzymes with enhanced antifungal activity by combining functional domains from native chitinases produced by B. subtilis and S. marcescens. Chitinase genes were cloned from both bacteria and fused together using overlap extension PCR. The hybrid constructs were expressed in E. coli and the recombinant enzymes purified. Gel electrophoresis and computational analysis confirmed the molecular weights and isoelectric points of the hybrid chitinases were intermediate between the parental enzymes. Antifungal assays demonstrated that the hybrid chitinases inhibited growth of the fungus Fusarium oxysporum significantly more than the native enzymes and also showed fungicidal activity against Candida albicans, Alternaria solani, and Rhizoctonia solani. The results indicate that hybrid bacterial chitinases are a promising approach to engineer novel antifungal proteins. This study provides insight into structure-function relationships of chitinases and strategies for generating biotherapeutics with enhanced bioactive properties. These hybrid chitinases result in a more potent and versatile antifungal agent.

Post harvest eco-friendly management of fruit rot of tomato caused by Alternaria solani

Post harvest eco-friendly management of fruit rot of tomato caused by Alternaria solani

Potato disease detection and control measure recommendation using CNN

Potato cultivation will continue to be a crucial agricultural endeavor, significantly enrich to global food supply. and economic prosperity. However, the ongoing vulnerability of potatoes to diseases, particularly named early Blight and late Blight, will persist as a substantial threat to crop yield and quality. Traditional disease identification methods, reliant on expert visual inspection, are expected to remain time-consuming, error-prone, and inadequate for timely intervention. This paper will outline to find Potato diseases and recommend effective control measures using convolutional Neural-Networks (CNN). The project will adopt an object-oriented methodology to ensure modularity and maintainability, leveraging TensorFlow for comprehensive dataset collection, data cleaning, and model training. TensorFlow Lite will be applied to optimize and quantify the developed model, enhancing the efficiency of the deployment process. The frontend will be crafted with React Native to facilitate user accessibility and seamless interaction. The resulting deep learning technique is anticipated to exhibit high accuracy in identifying early-blight and late-blight in potato plants, enabling users to receive prompt and reliable disease predictions and actionable control suggestions. This innovative approach aims to downgrade crop losses, improve productivity, and foster sustainable agricultural practices, thereby bolstering global food security in the future.

Convolutional neural network as an efficient alternative to supervised learners for modelling plant diseases

The high productivity of the agricultural sector is crucial to the Global economy, as well as the national economy. For instance, India increased its nation's GDP by a factor of 17% to 18% in the past few decades. In India, the farming sector is the primary source of income. Numerous insects and illnesses have an impact on plant development, amount, and quality of products. Therefore, it is crucial to find the diseases early in the plant's development. Image processing is used to identify plant diseases and pests. Artificial intelligence, machine learning, and visual analysis have all been used in the past few decades to find and diagnose plant diseases. These computerized techniques are excellent for quickly monitoring vast acreage. In this study, we used the foliage of potato plants to identify diseased leaves affected by early blight, as well as late blight. A Comparison is thus laid between the Convolutional Neural Network (CNN) Model for this purpose, and the standard Supervised Learning Classifiers, like k – Nearest Neighbors, Support Vector Machine, AdaBoost, etc. The comparison is subjected not only towards the traditional Metrics, like Accuracy, Precision, etc. but is expanded to temporal domains as well, that is the time taken to compute the results. Also, the training, and testing split used while incorporating the model is another deciding factor in its performance. Several such training–testing splits are considered for such, and thereby, the convolutional Neural Network Model is found to be better in performance than the Supervised Machine Learners irrespective of the Splitting Ratio of the Training, and the Testing Data.

A crop disease severity index derived from transfer learning and feature fusion using enhanced OPTICS algorithm

The adoption of automated methods for the identification and assessment of tomato-related disorders is highly sought-after in the agriculture sector. Using this technology is crucial for reducing wasteful spending, increasing the efficiency of treatments, and ultimately growing more resilient crops by reducing losses in agricultural output and maximising the effectiveness of these processes. An automated method has been suggested for accurately identifying and classifying diseases using a single photograph. The described method for disease detection in tomato plants makes use of a computer vision-based technique. Image processing, ML, and deep learning are just a few of the methods that this strategy uses. The goal of this approach is to prevent tomato crops from being damaged by various illnesses by reducing the need of conventional procedures. Bacterial spot, early blight, late blight, leaf mould, spider mites, target spot, spotted spider mite, mosaic virus, and yellow leaf curl are all examples of these illnesses. The following ten diseases frequently strike tomato crops in India. By utilising picture segmentation in combination with the Enhanced OPTICS algorithm (EOPTICSA), the affected area of the tomato plant may be precisely detected and defined after image pre-processing procedures have been used. It may be necessary to look for certain visual signs in order to diagnose the previously mentioned illnesses. The primary goal of this study was to evaluate the efficacy of the EOPTICSA method for detecting diseases in plant leaves. To eliminate the geometric features associated with colour, texture, and leaf arrangement in the provided plant pictures, image segmentation and edge detection methods are employed. Using these methods allows us to achieve our goal. Various efficacy measures are used to assess and provide a technique recommendation. This research shows that when performance metrics are used to implement these strategies, the suggested strategy outperforms the current methods in terms of accuracy, precision, and F1-score. The process of detecting sickness involves several consecutive steps. Capturing images, segmenting them, detecting edges, and determining the infection’s severity are all steps in this process. To accomplish the goal of recognising and categorising different types of diseases that might impact tomato plants, the method of transfer learning is employed. As soon as the problem is identified, it is recommended to take proactive measures to help individuals and organisations involved in agriculture address the effects of these disorders using appropriate measures.

In vitro Evaluation on Efficacy of Bioagents and Plant Extracts against Early Blight of Tomato (Alternaria alternata)

AIMS: In vitro evaluation on efficacy of Bioagents and plant extracts against Early blight of tomato (Alternaria alternata) Study Design: CRD (Completely Randomized Design). Place and Duration of Study: A trial was conducted in plant pathology laboratory at HRS Venkataramannagudem, Dr. Y.S.R. Horticultural University, Venkataramannagudem, during 2022. Methodology: The efficacy of bioagents were tested against isolates for radial growth inhibition on suitable media (Potato dextrose media and Nutrient agar media) using dual culture technique under in vitro conditions. The poisoned food technique was followed to evaluate theefficacy of botanicals in inhibiting the mycelial growth of test pathogen. Results: In the present investigation total nine bioagents and four plants extracts were tested against Alternariaalternata under in vitro. Results revealed that among the nine antagonists., Trichoderma harzianum, Tichoderma viride, Tichoderma longibraciatum (TCT4), Trichoderma reesi (TCT10), A10 (Tichoderma asperellum), A28 (Trichoderma harzianum), Trichoderma virens and two bacterial bioagents Pesudomonas fluorescens and Baciilus subtillis tested against A. alternata, maximum reduction in colony growth of A. alternata was observed in A10 (T. asperellum) (69.50%) and significantly superior over all other bioagents tested which was followed by A28 (T. harzianum) (62.96%) and the next best was T. virens (60.28%). Least inhibition was noticed in Bacillus subtillis (46.69%). Total four plant extracts neem leaves (Azadirachta indica), onion bulb (Allium cepa), garlic bulb (Allium sativum), and turmeric rhizome (Curcuma longa) tested at three concentrations (5, 7.5, 10 %) with suitable control by poisoned food technique against A. alternata, onion bulb extract (44.07%) which was found superior to all other tested botanicals. Least mean per cent inhibition was recorded with turmeric (21.34%).

Design, Synthesis, Antifungal Evaluation, and Three-Dimensional Quantitative Structure-Activity Relationship of Novel 5-Sulfonyl-1,3,4-thiadiazole Flavonoids.

Plant pathogenic fungi frequently disrupt the normal physiological and biochemical functions of plants, leading to diseases, compromising plant health, and ultimately reducing crop yield. This study aimed to address this challenge by identifying antifungal agents with innovative structures and novel mechanisms of action. We designed and synthesized a series of flavonoid derivatives substituted with 5-sulfonyl-1,3,4-thiadiazole and evaluated their antifungal activity against five phytopathogenic fungi. Most flavonoid derivatives demonstrated excellent antifungal activity against Botrytis cinerea (B. cinerea), Alternaria solani (A. solani), Rhizoctorzia solani (R. solani), Fusarium graminearum (F. graminearum), and Colletotrichum orbiculare (C. orbiculare). Specifically, the EC50 values of 38 target compounds against R. solani were below 4 μg/mL, among which the compounds C13 (EC50 = 0.49 μg/mL), C15 (EC50 = 0.37 μg/mL), and C19 (EC50 = 0.37 μg/mL) had the most prominent antifungal activity, superior to that of the control drug carbendazim (EC50 = 0.52 μg/mL). Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images of the cellular ultrastructures of R. solani mycelia and cells after treatment with the compound C19 revealed sprawling growth of hyphae, a distorted outline of their cell walls, and reduced mitochondrial numbers. Studying the 3D-QSAR between the molecular structure and antifungal activity of 5-sulfonyl-1,3,4-thiadiazole-substituted flavonoid derivatives could significantly improve conventional drug molecular design pathways and facilitate the development of novel antifungal leads.

Assessment of Early Blight Disease Resistant Tomato F1 Hybrid Arka Abhed in Karimnagar District of Telangana, India

Tomato is the major Solanaceous vegetable crop grown in Karimnagar District of Telangana. Alternaria tomatophila and Alternaria solani cause early blight disease and severe yield losses to the tomato growers in Karimnagar District. Early blight is the major problem in Karimnagar from June to September months causing severe crop losses to the tomato farmers. Usually farmers are spraying different fungicides based on Copper to control early blight disease for private hybrids. It controls 25-35% of the disease and increased cost of cultivation. Hence, early blight disease resistant hybrid Arka Abhed was tested against private hybrid in KVK, Karimnagar operational area. Data on disease incidence was collected at 15, 30, 60, 90,120 DAP in all the hybrids. The data revealed that Arka abhed recorded significantly very lower incidence of early blight disease than private hybrid during all crop growth stages. It recorded 1.5% early blight incidence whereas private hybrid recorded 32.4%. Reduced number of sprayings to control early blight disease were also significantly low i.e. two sprays were carried out whereas in private hybrid seven sprays were done during in rainy period. According to yield Arka Abhed recorded 68.3t/ha whereas it was 58.6t/ha in private hybrid. The peduncle in green in colour for long days and taste also same for all the days in storage period for 8-12 days in Arka Abhed. Average fruit weight is 86 gr to 112 grams were recorded.