Mahfuzur Rahman

Wheat blast, caused by Magnaporthe oryzae pathotype Triticum (MoT), poses a major, escalating threat to global wheat production, particularly in South Asia. This study systematically evaluated the biocontrol and yield-enhancing potential of three seed-associated Bacillus strains, Bacillus subtilis BTS-3, B. velezensis BTS-4, and BTLK6A, against MoT under both greenhouse (seed priming, preventive, and curative foliar application) and field conditions (seed priming and foliar spray). Seed priming with BTS-4 demonstrated significant disease suppression, reducing leaf blast severity by up to 89.88%. Synergistic seed priming treatment further enhanced protection, with the BTS-3 + BTS-4 consortium achieving 93.38% reduction of the disease in the seedling assay. Notably, preventive foliar application of BTS-4 also resulted in complete leaf blast suppression (0% severity), demonstrating its prophylactic efficacy, whereas curative treatments were comparatively less effective. Three years of rigorous field trial data confirmed the high efficacy of the Bacillus treatments, with BTS-4 and the bacterial consortium consistently reducing blast severity by more than 50% compared with the negative control. More importantly, the biocontrol treatments significantly improved yield attributes, with the consortium achieving the highest grain yield. These results clearly demonstrated that biological control treatments, alone or combined with fungicide, outperformed the negative control by 86.2% and the standard chemical fungicide (Nativo) treatment by 47.3%, respectively. These findings highlight the strong potential of these Bacillus strains, particularly the BTS-4 and consortium treatments, as sustainable, superior biocontrol agents for the integrated management of wheat blast and field-scale crop productivity enhancement.

Septoria leaf spot (SLS), caused by Septoria lycopersici Speg., is an important and increasingly prevalent foliar disease of tomato (Solanum lycopersicum L.) with no commercially resistant cultivars available. We screened 22 cultivated and wild accessions against a prevalent S. lycopersici isolate (WV21-1) and identified S. peruvianum LA2744 and S. corneliomulleri LA1910 as highly resistant (score 1 on a 1-to-5 scale), with S. arcanum LA1984 as resistant (score 2), whereas cultivated accessions scored 4 to 5. Using an optimized ovule rescue protocol with a 25-to-35-day rescue window after pollination, we recovered five confirmed interspecific F ₁ hybrids from 34,475 cultured ovules. Hybridity was validated with a 24-marker genome-wide cleaved amplified polymorphic sequence (CAPS) panel, which also identified two self-escapes. Most F ₁ plants exhibited post-zygotic incompatibility, preventing direct backcrossing. Using of cv. Micro-Tom as a bridging parent overcame this barrier, yielding approximately 17 BC ₁ plants per 100 pollinations. Segregating populations displayed continuous SLS score distributions and high broad-sense heritability (H ² =0.80-0.84), consistent with quantitative resistance. Composite interval mapping identified putative resistance-associated regions. In the S.arcanum-derived BC ₁ (n=169), a candidate locus on chromosome 8, with the wild allele conferring resistance, was significant in the multiple QTL model (P=0.003; 4.9% variance) but did not exceed the genome-wide threshold. In the S. peruvianum-derived ΨF2 (n=354), no locus reached significance. Beyond mapping, this study delivers an integrated, reproducible pipeline (donor screening, species-specific ovule rescue, low-cost CAPS-based hybrid validation, and Micro-Tom bridging) that converts wild SLS resistance into validated, backcross-ready material and nominates chromosome 8 for fine-mapping.

Wheat blast caused by the fungus Magnaporthe oryzae Triticum (MoT) pathotype is a catastrophic disease that threatens global food security. Recently, Rmg8 was discovered as a blast resistance gene in wheat genotype S615. However, although Rmg8 has recently been cloned, the precise underlying biochemical and molecular mechanisms by which this gene confers resistance against MoT remain to be fully elucidated. This study investigated the antioxidant defense mechanisms in the wheat genotype S615, which carries the blast resistance gene Rmg8 against MoT infection, compared with the blast-susceptible wheat variety BARI Gom-26 (BG26). Artificial inoculation of wheat heads with MoT followed by biochemical analyses revealed that the levels of hydrogen peroxide (H ₂ O ₂ ), lipoxygenases (LOXs), and malondialdehyde (MDA) in rachis tissues increased significantly until 48 h after inoculation in both S615 and BG26. However, LOX and MDA concentrations were substantially lower in S615 than in BG26. These biochemical alterations may have contributed to less damage to photosynthetic pigments, such as chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the rachis of S615. The S615 genotype exhibited significantly higher levels of several enzymatic (superoxide dismutase, catalase, ascorbate peroxidase, glutathione peroxidase, glutathione reductase, dehydroascorbate reductase, and monodehydroascorbate reductase) and non-enzymatic (e.g., proline) antioxidants in the MoT-inoculated rachis tissues than in those of BG26. To the best of our knowledge, this study biochemically demonstrates for the first time that the blast resistance in S615 is, in part, correlated with its strong antioxidant defense responses to MoT infection, providing a physiological basis for this resistance mechanism.

As an emerging threat to global food security, wheat blast necessitates the development of a rapid and field-deployable detection system to facilitate early diagnosis, enable effective management, and prevent its further spread to new regions. In this study, we aimed to validate and improve a Recombinase Polymerase Amplification coupled with PCRD lateral flow detection (RPA-PCRD strip assay) kit for the rapid and specific identification of Magnaporthe oryzae pathotype Triticum (MoT) in field samples. The assay demonstrated exceptional sensitivity, detecting as low as 10 pg/µL of target DNA, and exhibited no cross-reactivity with M. oryzae Oryzae (MoO) isolates and other major fungal phytopathogens under the genera of Fusarium, Bipolaris, Colletotrichum, and Botrydiplodia. The method successfully detected MoT in wheat leaves as early as 4 days post-infection (DPI), and in infected spikes, seeds, and alternate hosts. Furthermore, by combining a simplified polyethylene glycol-NaOH method for extracting DNA from plant samples, the entire RPA-PCRD strip assay enabled the detection of MoT within 30 min with no specialized equipment and high technical skills at ambient temperature (37–39 °C). When applied to field samples, it successfully detected MoT in naturally infected diseased wheat plants from seven different fields in a wheat blast hotspot district, Meherpur, Bangladesh. Training 52 diverse stakeholders validated the kit’s field readiness, with 88% of trainees endorsing its user-friendly design. This method offers a practical, low-cost, and portable point-of-care diagnostic tool suitable for on-site genomic surveillance, integrated management, seed health testing, and quarantine screening of wheat blast in resource-limited settings. Furthermore, the RPA-PCRD platform serves as an early warning modular diagnostic template that can be readily adapted to detect a wide array of phytopathogens by integrating target-specific genomic primers.

As an emerging threat to global food security, wheat blast necessitates the development of a rapid and field-deployable detection system to facilitate early diagnosis, enable effective management, and prevent its further spread to new regions. In this study, we aimed to validate and improve an Recombinase Polymerase Amplification coupled with PCRD lateral flow detection (RPA-PCRD strip assay) kit for the rapid and specific identification of Magnaporthe oryzae pathotype Triticum (MoT) in field samples. The assay demonstrated exceptional sensitivity, detecting as low as 10 pg/µL of target DNA, and exhibited no cross-reactivity with M. oryzae Oryzae (MoO) isolates and other major fungal phytopathogens under the genera of Fusarium, Bipolaris, Colletotrichum and Botrydiplodia. The method successfully detected MoT in wheat leaves as early as 4 days post-infection (DPI) (asymptomatic plants), as well as in infected spikes, seeds, and alternate hosts. Furthermore, by combining a simplified polyethylene glycol-NaOH method for extracting DNA from plant samples, the entire RPA-PCRD strip assay enabled the detection of MoT within 30 min with no specialized equipment and high technical skills at ambient temperature (37-39 °C). When applied to field samples, it successfully detected MoT in naturally infected diseased wheat plants from seven different fields in wheat blast hotspot district, Meherpur in Bangladesh. This method offers a practical, low-cost, and portable point-of-care diagnostic tool suitable for on-site surveillance, integrated management, seed health testing, and quarantine screening of wheat blast in resource-limited settings. Furthermore, the RPA-PCRD platform serves as a modular diagnostic template that can be readily adapted to detect a wide array of phytopathogens by integrating target-specific genomic primers.

Blackleg caused by a hemi-biotrophic fungus Plenodomus lingam (syn. Leptosphaeria maculans) poses a significant threat to global canola production. Changing climatic conditions further exacerbate the intensity and prevalence of blackleg epidemics. Shifts in temperature, humidity, and precipitation patterns can enhance pathogen virulence and disease spread. This review synthesizes the knowledge on integrated disease management (IDM) approaches for blackleg, including crop rotation, resistant cultivars, and chemical and biological controls, with an emphasis on advanced strategies such as disease forecasting models, remote sensing, and climate-adapted breeding. Notably, bibliometric analysis reveals an increasing research focus on the intersection of blackleg, climate change, and sustainable disease management. However, critical research gaps remain, which include the lack of region-specific forecasting models, the limited availability of effective biological control agents, and underexplored socio-economic factors limiting farmer adoption of IDM. Additionally, the review identifies an urgent need for policy support and investment in breeding programs using emerging tools like AI-driven decision support systems, CRISPR/Cas9, and gene stacking to optimize fungicide use and resistance deployment. Overall, this review highlights the importance of coordinated, multidisciplinary efforts, integrating plant pathology, breeding, climate modeling, and socio-economic analysis to develop climate-resilient, locally adapted, and economically viable IDM strategies for sustainable canola production.

Anthracnose diseases, caused by Colletotrichum spp., are considered to be among the most destructive diseases that have a significant impact on the global production of strawberries. These diseases alone can cause up to 70% yield loss in North America. Colletotrichum spp. causes several disease symptoms on strawberry plants, including root, fruit, and crown rot, lesions on petioles and runners, and irregular black spots on the leaf. In many cases, a lower level of infection on foliage remains non-symptomatic (quiescent), posing a challenge to growers as these plants can be a significant source of inoculum for the fruiting field. Reliable detection methods for quiescent infection should play an important role in preventing infected plants’ entry into the production system or guiding growers to take appropriate preventative measures to control the disease. This review aims to examine both conventional and emerging approaches for detecting anthracnose disease in the early stages of the disease cycle, with a focus on newly emerging techniques such as remote sensing, especially using unmanned aerial vehicles (UAV) equipped with multispectral sensors. Further, we focused on the acutatum species complex, including the latest taxonomy, the complex life cycle, and the epidemiology of the disease. Additionally, we highlighted the extensive spectrum of management techniques against anthracnose diseases on strawberries and their challenges, with a special focus on new emerging sustainable management techniques that can be utilized in organic strawberry systems.

Anthracnose and root rot are major foliar and root diseases of strawberry, respectively that cause most yield and quality losses. Anthracnose is caused by multiple species belonging to Colletotrichum spp complex. This disease alone can causeup to 70% yield loss in North America. Colletotrichum spp. cause several disease symptoms on strawberries, including root, fruit, and crown rot, lesions on petioles and runners, and irregular black spots on the leaf. In many cases, a lower level of infection on foliage remains non-symptomatic (quiescent), posing a challenge to growers as these plants can be a significant source of inoculum for the fruiting field. Reliable detection methods for quiescent infection should play an important role in preventing infected plants' entry into the production system or guiding growers to take appropriate preventative measures to control the disease. The selection of highly effective fungicides and including them in a schedule to prevent the development of fungicide resistance in fungal populations will remain an area of continued research. Disease management methods should entail sensitive molecular testing of suspected fungal isolates for resistance, rotation of products, and monitoring of quiescent infections in transplant materials. Testing and the inclusion of non-chemical methods such as biologicals and biorational treatments especially for soilborne pathogens will also be necessary to make disease management economically feasible and sustainable.

Black root rot complex and crown rot of strawberry caused by soilborne fungi limit sustainable strawberry production in the northeastern United States, especially in perennial systems, including matted row and plasticulture. As pathogen populations build up over time in the rhizosphere and infect the root system, feeder roots are pruned, which diminishes nutrient and water uptake and causes stunted plant growth or death. Alternative management options are needed for organic and many small growers who can’t use chemical fumigants due to new regulations and potential health hazards. Strawberry plug plants were grown on beneficial microbes-inoculated or uninoculated planting mix followed by transplanting in fruiting field plots that either was biofumigated with mustard cover crop (MCC), anaerobically disinfested (ASD) or left untreated. Different combinations of plug plants and field plot treatments were used to determine efficacy of individual treatments or synergistic effect from combination treatment. Plug plants were transplanted in pretreated plastic mulched raised beds and grown following a typical organically recommended production system. Plants grown on TerraGrow (TG)-inoculated planting mix showed enhanced plant vigor in the fruiting field compared with untreated plants. Weeds that grew through planting holes were significantly (P≤0.045) suppressed in ASD plots compared with untreated in the first year. Plants treated with a combination treatment of TG and ASD had significantly higher fruit yield in both years (2019 and 2020) although the difference was greater in the second year. Plant vigor and survival in treated plots except MCC were also significantly higher in the second year compared with the untreated control. Suppression of pathogenic microbes and plant vigor improvement in treated plots appear to be the factors providing beneficial effects and higher net economic return. Taken together, our results suggest that a combination of beneficial microbes and ASD could be an alternative to synthetic fumigation in a perennial strawberry production system.