Aug 2026· Pest Management Science· 0 citations· 93 references
Medicine
TL;DR
The findings elucidate the genomic basis underlying the strong invasiveness of this nematode, clarify its global dispersal routes, and identify putative loci associated with adaptive evolution after invasion.
Abstract
Background
Bursaphelenchus xylophilus is one of the most destructive invasive alien species in global forestry, causing widespread pine mortality and severe ecological damage. Clarifying its evolutionary patterns, invasion routes and adaptive signatures helps refine the evolutionary theory of plant-parasitic nematodes, and provides practical references for invasion prevention and targeted management.
Results
The first chromosome-level gap-free reference genome of B. xylophilus was assembled. The genome spans 78.02 Mb with a contig N50 of 12.60 Mb. All sequences were anchored to six chromosomes, and the BUSCO completeness was estimated at 99.50%. Comparative genomic analysis revealed that B. xylophilus and Bursaphelenchus mucronatus diverged approximately 4.85-24.67 million years ago. Further evolutionary analysis of gene families indicated a striking evolutionary asymmetry between these two species. Population structure analysis revealed that global B. xylophilus populations can be classified into four major genetic groups. Gene flow analyses suggest two potential invasion centers may exist in China. Through the integration of selective sweep analysis, we also identified putative adaptive loci in the two Chinese populations. Due to sampling limitations, the exact geographical origins of some overseas isolates remain unclear, and samples from key regions including South Korea and Europe are not included in this study. Accordingly, the inferences regarding invasion routes need to be further verified with additional population data.
Invasive apple snails (
Pomacea
spp.) have caused severe ecological and agricultural damage globally. Revealing their invasion history and genetic background is critical for effective management; however, traditional single-locus markers often provide insufficient resolution for deciphering complex dispersal routes or cryptic maternal lineage structures. Here, we conducted a comprehensive phylogeographic study by analyzing 428 complete mitochondrial genomes from China and Southeast Asia and 3,132 global
COI
sequences of three apple snail species, including
P. canaliculata
,
P. maculata
, and
P. occulta
. Mitogenomic analysis revealed a complex invasion history of
P. canaliculata
, and high genetic diversity was maintained in this species largely due to multiple independent introductions of three genetically divergent maternal lineages. We further resolved widespread
COI
haplotypes into finer geographic structure, highlighting the complexity of regional invasion and dispersal of
P. canaliculata
. In contrast,
P. maculata
in mainland China exhibited a single mitogenomic haplotype, consistent with a more restricted maternal pattern in the current dataset. Furthermore, our analysis identified that the recent outbreak of
P. canaliculata
in Kenya likely represents a secondary invasion event originating from Asian populations, highlighting a bridgehead effect.
COI
-based neutrality tests and mismatch analyses indicated that some invasive lineages experienced rapid recent population expansion, contrasting with the long-term stability of native populations. These findings provide essential genetic evidence and high-resolution resources for the global monitoring and biosecurity management of invasive apple snails.
Bitterlings (Acheilognathidae) exhibit a unique reproductive strategy characterized by symbiotic embryonic development inside the gill cavities of freshwater unionid mussels. Despite extensive ecological and physiological research on this system, genomic resources for bitterlings have remained limited, hindering comparative and evolutionary studies. Here, we present a high-quality, chromosome-level genome assembly for Rhodeus sinensis, a widely distributed bitterling species in the Korean Peninsula. By combining PacBio Continuous Long Read (CLR) sequencing, Illumina short reads, and Hi-C scaffolding, we generated a 0.77 Gb genome assembly with a scaffold N50 of 30.06 Mb. The final assembly comprises 24 chromosome-scale scaffolds, accounting for 98.3% of the assembled genome, with a BUSCO completeness score of 96.3% against the Actinopterygii_odb10. Comparative genomic analyses identified prominent expansions in gene families associated with alcohol metabolism, lipid catabolism, and oxidative stress responses. These genomic signatures of metabolic rewiring suggest a potential fuel flexibility, which may serve as a critical adaptive mechanism to mitigate the severe hypoxic stress encountered within the host mussel's gill environment. Ultimately, our chromosome-level genome assembly and findings provide a robust genomic foundation, contributing to a deeper understanding of the extreme physiological adaptations and unique life-history evolution within the Acheilognathidae.
Rawon Jeong, Jeonghun Kim, Young-Suk Ho· G3· 0 citations
A robust single-nucleotide polymorphism (SNP) discovery strategy is designed and applied to existing and novel sequence data sets that represent the global diversity in potato production systems and indicates that potato wart was introduced into Canada from a European source.
Jeremy R. Dettman, B. van de Vossenberg, T. V. D. van der Lee et al.· Mycologia· 0 citations
Orosanga japonica (Hemiptera: Ricaniidae) is an invasive, polyphagous planthopper established in Türkiye since 2007 that threatens economically important perennial and field crops across the Black Sea region. Although its establishment and rapid spread suggest considerable adaptive capacity, the genomic basis of this potential remains unexplored. We combined whole-genome sequencing with RNA-Seq data to generate a functionally annotated genome, recovering 92.5% of conserved single-copy orthologs. Utilizing these resources, we performed comparative genomic analyses across 20 additional hemipteran and thysanopteran species, investigating gene family dynamics and genome-wide positive selection. These analyses revealed 52 gene families with statistically significant, lineage-specific size changes (24 expansions and 28 contractions): expanded families were enriched for C2H2 zinc-finger transcription factors, α/β-hydrolases, major facilitator transporters, serpins, and chemosensory proteins, whereas contracted families included a cytochrome P450 family. Additionally, branch site tests identified 122 candidate genes under lineage-specific positive selection. These loci fall into three functional categories potentially associated with invasion-related traits: host detection and neuronal excitability, stress tolerance (xenobiotic, oxidative, and proteostatic), and barrier remodeling. Together, these genomic signatures highlight candidate molecular mechanisms that may contribute to host detection, xenobiotic tolerance, and ecological plasticity, providing a framework for evolutionary analysis and the targeted management of this emerging agricultural pest.
Yusuf Ulaş Çınar, Mehmet Ali Balcı, Onur Obut et al.· Insects· 0 citations
A nationwide multilocus assessment of ‘Ca. Phytoplasma’ diversity, distribution, and population structure across Indian agroecosystems provides important insights into phytoplasma diversity, host–pathogen interactions, and their implications for plant health and disease management.
Mantesh Muttappagol, Shridhar Hiremath, V. Venkataravanappa et al.· World Journal of Microbiolog...· 0 citations
Onychostoma lini
is an ecologically and economically important cyprinid species endemic to the mountain rivers of southern China. Wild populations have sharply declined due to habitat fragmentation, hydropower development, and overexploitation, yet genomic information remains unavailable, hindering studies on its diversity, adaptation, and conservation. Here, we assembled the first chromosome-level genome of
O. lini
using PacBio HiFi long-read sequencing, Illumina short-read polishing, and Hi-C scaffolding. The 907.5 Mb assembly achieved a contig N50 of 32.83 Mb and a scaffold N50 of 34.89 Mb, with 99.93% of sequences anchored to 25 chromosomes. Repetitive elements occupied 387.36 Mb, representing 42.69% of the genome. We predicted 28,597 protein-coding genes, 99.05% of which were functionally annotated in NR, KEGG, InterPro, SwissProt, and GO databases. BUSCO analysis identified 97.9% complete orthologs, confirming assembly completeness and annotation accuracy. This high-quality reference genome provides a foundational resource for investigating cyprinid evolution, environmental adaptation, and molecular breeding, and supports the conservation of
O. lini
.
Xuan Xie, Li Zou, Zhonggui Xie et al.· Scientific Data· 0 citations
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