Streptomyces malaysiensis subsp. malaysiensis strain 17-7 was isolated from rubber tree rhizosphere soil. This strain exhibits potent biocontrol activity against rubber tree brown root rot and other fungal diseases that infect rubber trees. To unravel its underlying biocontrol mechanisms, we performed whole-genome sequencing of strain 17-7, combining Illumina second-generation short-read and PacBio third-generation long-read platforms. The assembled genome totals 11,745,489 bp, consisting of a single chromosome with an average GC content of 70.98%. Genome annotation predicted 9,529 protein-coding genes, alongside 18 rRNAs, 64 tRNAs, 125 sRNAs, 25 genomic islands, 8 prophages, and 2 CRISPR arrays. Furthermore, a total of 51 secondary metabolite biosynthetic gene clusters were annotated across the 17-7 genome, responsible for the biosynthesis of polyketides, terpenes, siderophores, and peptides. This high-quality genomic resource lays a solid basis for systematically dissecting the molecular biocontrol mechanisms of strain 17-7. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
Rapid and accurate diagnosis of ‘ Candidatus Phytoplasma’ is critical for disease management but remains challenging due to the pathogen's unculturable nature, low titers, uneven distribution, and genetic complexity. Although current official guidelines provide a highly adaptable taxonomic foundation for species assignment, translating these broad recommendations into standardized routine diagnostics remains difficult. This study implemented the established species assignment guidelines by developing a structured, proof-of-concept diagnostic framework utilizing a multilocus sequence analysis workflow coupled with Oxford Nanopore Technologies (ONT) sequencing. The developed workflow targets four barcodes—16S, secA, rplV, and tufB—and replaces fixed demarcation criteria with a best-match principle for non-16S barcodes. Furthermore, the study offers guidance for barcode selection and challenges the use of 16S rRNA sequencing as a sole screening assay. Moreover, a read-based quantification system incorporating control thresholds was implemented to provide an objective and reliable assessment of the results. The workflow was validated using a spiked dilution series and naturally infected samples, demonstrating that the ONT workflow achieves sensitivity and accuracy comparable to, or exceeding, that of traditional Sanger sequencing. Although PCR multiplexing was found to reduce sensitivity, limiting the immediate throughput advantages over Sanger sequencing, the proposed framework offers significant value through flexible species assignment and stringent contamination controls. Consequently, this method serves as a robust, high-resolution tool for resolving complex phytoplasma infections. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY 4.0 International license .
Fungicide application method and crop canopy structure can influence spray deposition, disease control, and yield in corn ( Zea mays L.), yet their interactions remain poorly understood, particularly in short-stature hybrids. Field experiments were conducted in Iowa and Kentucky during 2023 and 2024 to evaluate the effects of hybrid architecture (short versus tall stature) and fungicide application method (aerial, ground, unmanned aerial vehicle [UAV], and 360 Undercover) on spray deposition, foliar disease severity, and grain yield. Fungicide deposition was quantified using a fluorescent tracer dye measured across canopy positions and distances from the spray swath center. Deposition differed among application methods, canopy positions, and row locations, with ground and UAV applications generally providing greater deposition than aerial applications. Deposition was greatest in the upper canopy and declined toward lower canopy positions, whereas 360 Undercover improved lower-canopy deposition. Despite these differences, fungicide applications reduced foliar disease severity relative to the nontreated control across environments, with minor differences among application methods. Tar spot ( Phyllachora maydis) and southern rust ( Puccinia polysora) were observed in Iowa, and gray leaf spot ( Cercospora zeae-maydis, C. zeina) occurred in Kentucky. Grain yield increased with fungicide application, but differences among application methods were small and inconsistent. Overall, the results indicate that multiple application systems can provide effective disease control and yield protection when fungicides are applied at the appropriate growth stage and that adequate deposition, rather than maximum deposition, is sufficient for managing major foliar diseases in corn. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
Drought is increasingly recognized as an important factor shaping plant-associated microbiomes, yet field evidence linking variation in root microbial communities to contrasting plant health outcomes under drought conditions remains limited. During the 2022 growing season, an extended drought period coincided with the occurrence of severely symptomatic faba bean plants growing alongside asymptomatic plants within the same plots. Because soil type, management, plant genotype, and field history were identical, this provided an opportunity to examine whether differences in the root-associated fungal community were associated with contrasting plant health states. We combined ITS1 amplicon sequencing with quantitative PCR (qPCR) targeting major root rot pathogens and arbuscular mycorrhizal fungi (AMFs) in roots of asymptomatic and symptomatic plants. Although the pathogen spectrum was similar in both health states, qPCR revealed substantially higher abundances of Fusarium spp. and Didymella pinodella in symptomatic plants. Symptomatic plants showed significantly lower fungal species richness and a distinct community structure compared with asymptomatic plants. Indicator species analysis identified 23 taxa associated with asymptomatic plants, including Mortierella spp. and several other taxa previously linked to plant stress tolerance, whereas only three taxa were associated with symptomatic plants. Asymptomatic plants also showed higher AMF abundance. These findings demonstrate that asymptomatic and symptomatic faba bean plants occurring during a severe drought year harbored contrasting root fungal communities and pathogen loads. Although the observational nature of the study precludes conclusions regarding causality, the results highlight a close association between environmental factors, plant health status, and fungal community composition under field conditions. [Formula: see text] Copyright © 2026 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license .
Global growth in soilless plant production systems, coupled with an increase in the soilless production of many traditional field-grown horticultural crops, has substantially increased demand for soilless substrates. This demand, as well as increasing interest in reducing industry dependence on peat, has prompted growers to incorporate non-peat materials into their substrates, such as engineered wood fibers (WFs). While WFs have shown potential to enhance the suppressiveness of peat against Rhizoctonia solani, the breadth and mechanisms of this suppression remain unclear. Existing evidence suggests WF effects on substrate microbiomes may play a role: other substrate amendments, such as straw, can increase microbiome diversity, and more diverse microbiomes can be disease suppressive. Here, we evaluated the effects of three engineered pine WF-amendments on disease suppression and microbiome composition using Globisporangium ultimum root rot of chrysanthemum (Chrysanthemum × morifolium) as a model system. The three WF-amendments used in this study were processed using either disc refinement, screw-extrusion, or hammer-milling. Results indicate that hammer-milled and extruded WFs reduced Globisporangium root rot in chrysanthemums and maintained chrysanthemum growth equal to grower standard media in the absence of Globisporangium. 16s rRNA and ITS amplicon sequencing data of substrate samples revealed that fungal and bacterial alpha diversity did not increase in any WF-amended substrates compared to peatlite standards and was not correlated to disease severity in most treatments. However, some microbiome composition differences were driven by WF amendment type, suggesting that WF-driven community turnover could relate to disease suppression.
