New isolate of sweet potato virus 2 from Ipomoea nil: molecular characterization, codon usage bias, and phylogenetic analysis based on complete genome.

BACKGROUND: Viral diseases of sweet potatoes are causing severe crop losses worldwide. More than 30 viruses have been identified to infect sweet potatoes among which the sweet potato latent virus (SPLV), sweet potato mild speckling virus (SPMSV), sweet potato virus G (SPVG) and sweet potato virus 2 (SPV2) have been recognized as distinct species of the genus Potyvirus in the family Potyviridae. The sweet potato virus 2 (SPV2) is a primary pathogen affecting sweet potato crops. METHODS: In this study, we detected an SPV2 isolate (named SPV2-LN) in Ipomoea nil in China. The complete genomic sequence of SPV2-LN was obtained using sequencing of small RNAs, RT-PCR, and RACE amplification. The codon usage, phylogeny, recombination analysis and selective pressure analysis were assessed on the SPV2-LN genome. RESULTS: The complete genome of SPV2-LN consisted of 10,606 nt (GenBank No. OR842902), encoding 3425 amino acids. There were 28 codons in the SPV2-LN genome with a relative synonymous codon usage (RSCU) value greater than 1, of which 21 end in A/U. Among the 12 proteins of SPV2, P3 and P3N-PIPO exhibited the highest variability in their amino acid sequences, while P1 was the most conserved, with an amino acid sequence identity of 87-95.3%. The phylogenetic analysis showed that 21 SPV2 isolates were clustered into four groups, and SPV2-LN was clustered together with isolate yu-17-47 (MK778808) in group IV. Recombination analysis indicated no major recombination sites in SPV2-LN. Selective pressure analysis showed dN/dS of the 12 proteins of SPV2 were less than 1, indicating that all were undergoing negative selection, except for P1N-PISPO. CONCLUSION: This study identified a sweet potato virus, SPV2-LN, in Ipomoea nil. Sequence identities and genome analysis showed high similarity between our isolate and a Chinese isolate, yu-17-47, isolated from sweet potato. These results will provide a theoretical basis for understanding the genetic evolution and viral spread of SPV2.

Complete mitochondrial genome and phylogenetic analysis of Dollfustrema vaneyi (Trematoda: Bucephalidae).

BACKGROUND: The Bucephalidae is a large family of digenean trematodes but most previous analyses of its phylogenetic position have relied on a single mitochondrial gene or morphological features. Mitochondrial genomes (mitogenomes) remain unavailable for the entire family. To address this, we sequenced the complete mitogenome of Dollfustrema vaneyi and analyzed the phylogenetic relationships with other trematodes. RESULTS: The circular genome of Dollfustrema vaneyi spanned 14,959 bp and contained 12 protein-coding genes, 22 transfer RNA genes, 2 ribosomal RNA genes, and a major non-coding region. We used concatenated amino acid and nucleotide sequences of all 36 genes for phylogenetic analyses, conducted using MrBayes, IQ-TREE and PhyloBayes. We identified pronounced topological instability across different analyses. The addition of recently sequenced two mitogenomes for the Aspidogastrea subclass along with the use of a site-heterogeneous model stabilized the topology, particularly the positions of Azygiidae and Bucephalidae. The stabilized results indicated that Azygiidae was the closest lineage to Bucephalidae in the available dataset, and together, they clustered at the base of the Plagiorchiida. CONCLUSIONS: Our study provides the first comprehensive description and annotation of the mitochondrial genome for the Bucephalidae family. The results indicate a close phylogenetic relationship between Azygiidae and Bucephalidae, and reveal their basal placement within the order Plagiorchiida. Furthermore, the inclusion of Aspidogastrea mitogenomes and the site-heterogeneous model significantly improved the topological stability. These data will provide key molecular resources for future taxonomic and phylogenetic studies of the family Bucephalidae.

The complete chloroplast genome of Elaeagnus bambusetorum hand.-mazz. 1933 and its implications for phylogenetic relationships in the Elaeagnus genus.

Elaeagnus bambusetorum Hand.-Mazz. is a rare plant from China in the Elaeagnaceae family. In this study, we sequenced its complete chloroplast genome. The whole chloroplast genome was 152,265 bp in length, containing a pair of inverted repeats of 25,897 bp, separated by large single copy and small single copy regions of 82,291 bp and 18,180 bp, respectively. The complete genome contained 113 genes, including 79 protein-coding genes, 30 tRNA genes, and 4 rRNA genes. The overall GC content was 37.1%. Phylogenetic analysis using the whole chloroplast genome revealed that E. bambusetorum is sister to E. loureirii and E. conferta. Our study provides valuable insights into the genetic information of E. bambusetorum, which may have important implications for species conservation.

Diaporthe foeniculina and D. eres, in addition to D. ampelina, may cause Phomopsis cane and leaf spot disease in grapevine.

Phomopsis cane and leaf spot (PCLS) disease, affecting grapevines (Vitis vinifera and Vitis spp.), has been historically associated with Diaporthe ampelina. Typical disease symptoms, comprising bleaching and black pycnidia, have also been associated with other Diaporthe spp. In this study, we conducted a molecular identification of the Diaporthe isolates isolated from grapevine canes from different geographic areas of southern Europe showing PCLS symptoms. Then, we investigated their morphological characteristics (including mycelium growth and production of pycnidia and alpha and beta conidia) in response to temperature. Finally, we artificially inoculated grapevine shoots and leaves with a subset of these isolates. Based on our results, PCLS etiology should be reconsidered. Though D. ampelina was the most crucial causal agent of PCLS, D. eres and D. foeniculina were also pathogenic when inoculated on green shoots and leaves of grapevines. However, D. rudis was not pathogenic. Compared to D. ampelina, D. eres and D. foeniculina produced both pycnidia and alpha conidia at lower temperatures. Thus, the range of environmental conditions favorable for PCLS development needs to be widened. Our findings warrant further validation by future studies aimed at ascertaining whether the differences in temperature requirements among species are also valid for conidia-mediated infection since it could have substantial practical implications in PCLS management.

The complete chloroplast genome of Pilea notata C. H. Wright, 1899 (Urticaceae).

Pilea notata (Pilea notata C. H. Wright_C. H. Wright, 1899) is Pilea Lindl. of Urticaceae, which is a commonly used Miao medicine in Guizhou province. The P. notata chloroplast genome is 150,979 bp, contains a pair of inverted repeats (IRs 25,743bp), and is separated by a large single-copy region (81,446bp) and a small single-copy region (18,047bp). A total of 131 genes, including 86 protein-coding genes, 37 tRNA genes, and eight rRNA genes. Phylogenetic analysis showed that P. notata, P. verrucosa and P. monilifera united as a single branch, while Pilea cadierei was defined as a sister group of this branch.

Molecular detection of Babesia and Hepatozoon species and morphological characteristics of Babesia species in Japanese wild boars.

We investigated intraerythrocytic Babesia parasites in 21 Japanese wild boars, Sus scrofa leucomystax, captured in Wakayama Prefecture on the mainland from 2008 to 2009 and in 31 Japanese wild boars from 2011 to 2013 in Kochi Prefecture on Shikoku Island, Japan. We detected small subunit ribosomal RNA (18S rRNA) gene (SSUrDNA) fragments of a Babesia species in 17 boars from Wakayama and 18 boars from Kochi. The nearly full SSUrDNA sequence (1669 bps) of this species was determined. A FASTA search revealed that the SSUrDNA sequence of the Babesia sp. in Japanese wild boars was the most homologous to those of several Babesia isolates reported as Babesia gibsoni. Phylogenetic analysis showed that the Babesia sp. found in Japanese wild boars was the closest relative to B. gibsoni but made a different clade from B. gibsoni. The Babesia sp. in Japanese wild boars was completely different from Babesia sp. Suis found in a European domestic pig, Sus scrofa domesticus. By microscopic examination, ring-shaped, oval and pear-shaped small sized intraerythrocytic parasites were observed on blood smears of 12 of 18 Japanese wild boars whose blood smears could be examined in Wakayama. We also detected SSUrDNA fragments of a Hepatozoon species in 6 of the 21 wild boars from Wakayama. The nearly full SSUrDNA sequence (1774 bps) of the Hepatozoon sp. was shown to be identical to that of Hepatozoon apri.

The ancient mitochondrial genome of a Siberian roe deer (Capreolus pygargus) from Jartai Pass Site in Xinjiang, China, and its phylogenetic relationships.

The ancient mitochondrial genome of a Siberian roe deer (Capreolus pygargus) coded as NJ26S from Jartai Pass Site was obtained by high throughput sequencing. The damage pattern demonstrated the authenticity and reliability of the ancient DNA data. The length of the mitogenome was 16,357 bp, which contained 13 protein-coding genes, two rRNA genes, 22 tRNA genes, and one control region. The total base composition of the mitochondrial genome is 28.17% A, 25.01% T, 11.89% G, 19.72% C, and 15.21% missing data with an AT composition of 53.18%. A maximum-likelihood phylogenetic tree was recovered including other roe deer sequences under the TIM2 + I + G4 model. This study presents molecular evidence indicating the presence of Capreolus pygargus in the Xinjiang Uygur Autonomous Region in China more than 3,000 years ago.

Genetic heterogeneity of duck circovirus first detected in geese from China.

Duck circovirus (DuCV) can infect domestic and wild ducks, retarding growth and suppressing immunity, thereby increasing the possibility of secondary infection by other pathogens. In this study, for the first time, 2 DuCV strains (G221116 and G210917) were identified in geese from China. To study the genetic characteristics of the 2 goose-originated DuCVs, multiple sequence alignment and phylogenetic analyses were perforemed according to genome sequences of 2 DuCV strains g and reference waterfowl circoviruses retrieved from the GenBank database. Pairwise analysis showed that the genome sequence identities between the 2 DuCVs with reference DuCV-1 and DuCV-2 strains were 80.95% to 98.24%, and 58.04% to 59.55% with Goose circovirus (GoCV). Phylogenetic analysis showed that the 2 DuCVs belonged to DuCV-1 and DuCV-2 genotypes. These results broaden our understanding of the genetic heterogeneity and evolution of DuCV and suggest trans-host transmission of DuCV between ducks and geese.

Comparative and phylogenetic analysis of chloroplast genomes from ten species in Quercus section Cyclobalanopsis.

The genus Quercus L. is widely acknowledged as a significant assemblage within East Asia tropical and subtropical broadleaf evergreen forests, possessing considerable economic importance. Nevertheless, the differentiation of Quercus species is deemed arduous, and the interrelations among these species remain enigmatic. Leveraging Illumina sequencing, we undertook the sequencing and assembly of the chloroplast (cp) genomes of seven species belonging to Quercus section Cyclobalanopsis (Quercus argyrotricha, Q. augustinii, Q. bambusifolia, Q. bella, Q. edithiae, Q. jenseniana, and Q. poilanei). Furthermore, we collated three previously published cp genome sequences of Cyclobalanopsis species (Q. litseoides, Q. obovatifolia, and Q. saravanensis). Our primary objective was to conduct comparative genomics and phylogenetic analyses of the complete cp genomes of ten species from Quercus section Cyclobalanopsis. This investigation unveiled that Quercus species feature a characteristic circular tetrad structure, with genome sizes ranging from 160,707 to 160,999 base pairs. The genomic configuration, GC content, and boundaries of inverted repeats/single copy regions exhibited marked conservation. Notably, four highly variable hotspots were identified in the comparative analysis, namely trnK-rps16, psbC-trnS, rbcL-accD, and ycf1. Furthermore, three genes (atpF, rpoC1, and ycf2) displayed signals of positive selection pressure. Phylogenetic scrutiny revealed that the four sections of Cyclobalanopsis clustered together as sister taxa. The branch support values ranged from moderate to high, with most nodes garnering 100% support, underscoring the utility of cp genomic data in elucidating the relationships within the genus. Divergence time analysis revealed that Section Cyclobalanopsis represents the earliest type of Quercus genus. The outcomes of this investigation establish a foundation for forthcoming research endeavors in taxonomy and phylogenetics.

Alternaria alternata species complex impairing solanaceous vegetables in Northern parts of India: an emerging problem in Solanum lycopersicum L.

Severe incidence of Alternaria spp. was observed in the three solanaceous vegetables viz. tomato, potato and brinjal grown in National Capital Region of Delhi and Haryana. The symptomatic plants exhibited necrotic brown lesions on the leaves initiating from the lower older leaves and extending to stem, affecting the whole plant. Subsequently, black sooty sporulation was observed in fruits of tomato and brinjal crop. During the survey, tomato crop was most susceptible with 98.99% incidence, followed by brinjal with 82.36% and potato with 61.19% incidence. The mean plant disease index varied between 9.98% and 65.99% among the three crops. Isolation and characterization of the causal agent from symptomatic plants revealed association of small-spored Alternaria spp. in all crops. Further, morphological and Internal Transcribed Spacer (ITS) sequencing phylogenetic analysis ascertained the fungus belong to Alternaria section of Alternaria genus. As tomato was found most susceptible, host plant resistance was explored among 197 tomato germplasm/breeding lines under epiphytotic conditions. It was found that 08 accessions exhibited moderate resistance against pathogen. The findings in the study suggest that small-spored Alternaria is an emerging problem in the solanaceous vegetables and warrants attention for effective management of the disease. Supplementary Information: The online version contains supplementary material available at 10.1007/s13205-024-04059-7.

Aequorivita flava sp. nov., isolated from deep-sea sediments.

Three Gram-stain-negative, aerobic, non-motile, chemoheterotrophic, short-rod-shaped bacteria, designated CDY1-MB1T, CDY2-MB3, and BDY3-MB2, were isolated from three marine sediment samples collected in the eastern Pacific Ocean. Phylogenetic analysis based on 16S rRNA gene sequences indicated that these strains were related to the genus Aequorivita and close to the type strain of Aequorivita vitellina F4716T (with similarities of 98.0-98.1%). Strain CDY1-MB1T can grow at 15-37 °C (optimum 30 °C) and in media with pH 6-9 (optimum, pH 7), and tolerate up to 10% (w/v) NaCl. The predominant cellular fatty acids of strain CDY1-MB1T were iso-C15 : 0 (20.7%) and iso-C17 : 0 3-OH (12.8%); the sole respiratory quinone was menaquinone 6; the major polar lipids were phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. The digital DNA-DNA hybridization/average nucleotide identity values between strains CDY1-MB1T, CDY2-MB3, and BDY3-MB2 and A. vitellina F4716T were 24.7%/81.6-81.7%, thereby indicating that strain CDY1-MB1T should represent a novel species of the genus Aequorivita. The genomic DNA G+C contents were 37.6 % in all three strains. Genomic analysis showed the presence of genes related to nitrogen and sulphur cycling, as well as metal reduction. The genetic traits of these strains indicate their possible roles in nutrient cycling and detoxification processes, potentially shaping the deep-sea ecosystem's health and resilience. Based upon the consensus of phenotypic and genotypic analyses, strain CDY1-MB1T should be classified as a novel species of the genus Aequorivita, for which the name Aequorivita flava sp. nov. is proposed. The type strain is CDY1-MB1T (=MCCC 1A16935T=KCTC 102223T).

Complete genome assembly of Candida auris representative strains of three geographical clades.

The complete genome assembly of Candida auris strains B11103, B11221, and B11244 is reported in this manuscript. These strains represent the three geographical clades, namely, South Asian (Clade I), South African (Clade III), and South American (Clade IV).

Structure and distribution of sensor histidine kinases in the fungal kingdom.

Two-component systems (TCSs) are diverse cell signaling pathways that play a significant role in coping with a wide range of environmental cues in both prokaryotic and eukaryotic organisms. These transduction circuitries are primarily governed by histidine kinases (HKs), which act as sensing proteins of a broad variety of stressors. To date, nineteen HK groups have been previously described in the fungal kingdom. However, the structure and distribution of these prominent sensing proteins were hitherto investigated in a limited number of fungal species. In this study, we took advantage of recent genomic resources in fungi to refine the fungal HK classification by deciphering the structural diversity and phylogenetic distribution of HKs across a large number of fungal clades. To this end, we browsed the genome of 91 species representative of different fungal clades, which yielded 726 predicted HK sequences. A domain organization analysis, coupled with a robust phylogenomic approach, led to an improved categorization of fungal HKs. While most of the compiled sequences were categorized into previously described fungal HK groups, some new groups were also defined. Overall, this study provides an improved overview of the structure, distribution, and evolution of HKs in the fungal kingdom.

The first emergence of paramyxovirus type 12 in wild birds in mainland, China.

Avian paramyxoviruses (APMV) belong to the subfamily Avulavirinae of the family Paramyxoviridae and include 22 distinct subtypes or serotypes (1-22). Avian paramyxovirus serotype 12 (APMV-12) is found sporadically in wild birds worldwide, and reports from only Italy and Taiwan have been published to date; information on its genetic variation and biological characteristics is still limited. In this study, 3 APMV-12 strains, designated WB19, LY9, and LY11, were isolated from 8643 wild bird faecal samples during the annual influenza virus surveillance of wild birds in Guangdong, China between 2018 and 2024, which is first reported in mainland China. The complete genomes of the 3 viruses with 6 gene segments, 3'-N-P-M-F-HN-L-5', were 15,231 nt in length. Phylogenetic analysis based on the whole genome showed that the 3 APMV-12 strains had the highest homology with an APMV-12 strain isolated from Taiwan in 2015, followed by the prototype APMV-12 strains isolated from mallard ducks in Italy in 2005. Genetic analysis of the whole gene of each of them indicated that they were derived from a Eurasian lineage. This study provides additional evidence that wild birds transmit viruses between countries, and this should be monitored to understand APMV transmission, evolution and epidemiology.

Prevalence of Aleutian Mink Disease Virus (AMDV) in Free-Ranging American Mink from Biebrza and Narew National Parks (Poland)-An Epidemiological Concern.

Aleutian Mink Disease Virus (AMDV) is the causative agent of Aleutian disease (AD). This progressive and chronic disorder significantly impacts the mink breeding industry, affecting farmed and free-ranging American and European mink. This study investigated AMDV variants isolated from free-ranging American mink in northeastern Poland. Between 2018 and 2019, 26 spleen samples were collected from mink in Narew National Park (NNP) and Biebrza National Park (BNP). DNA was extracted and subjected to PCR to amplify the NS1 gene, followed by sequencing and phylogenetic analysis. The NS1 gene was detected in 50% of samples from NNP minks and in 30% of samples from BNP minks, with an overall prevalence of 42.31%; these findings align with global data and indicate serious ecological and health concerns. Ten closely related AMDV variants and one distinct variant were identified. The grouped variants exhibited high genetic homogeneity, closely related to strains found in mink from the USA, Germany, Greece, Latvia, and Poland; meanwhile, the distinct variant showed similarities to strains found in mink from Finland, Denmark, China, Poland, and Latvia, suggesting multiple infection sources. These findings, consistent with data from Polish mink farms, indicate significant genetic similarity between farmed and wild mink strains, suggesting potential bidirectional transmission. This underscores the importance of a One Health approach, emphasizing the interconnectedness of human, animal, and environmental health. Continuous surveillance and genetic studies are crucial for understanding AMDV dynamics and mitigating their impacts. Measures to reduce transmission between farmed and wild mink populations are vital for maintaining mink health and ecosystem stability.

Exploring the Roles of the Swi2/Snf2 Gene Family in Maize Abiotic Stress Responses.

The maize Snf2 gene family plays a crucial role in chromatin remodeling and response to environmental stresses. In this study, we identified and analyzed 35 members of the maize Snf2 gene family (ZmCHR1 to ZmCHR35) using the Ensembl Plants database. Each protein contained conserved SNF2-N and Helicase-C domains. Phylogenetic analysis revealed six groups among the Snf2 proteins, with an uneven distribution across subfamilies. Physicochemical analysis indicated that the Snf2 proteins are hydrophilic, with varied amino acid lengths, isoelectric points, and molecular weights, and are predominantly localized in the nucleus. Chromosomal mapping showed that these genes are distributed across all ten maize chromosomes. Gene structure analysis revealed diverse exon-intron arrangements, while motif analysis identified 20 conserved motifs. Collinearity analysis highlighted gene duplication events, suggesting purifying selection. Cis-regulatory element analysis suggested involvement in abiotic and biotic stress responses. Expression analysis indicated tissue-specific expression patterns and differential expression under various stress conditions. Specifically, qRT-PCR validation under drought stress showed that certain Snf2 genes were upregulated at 12 h and downregulated at 24 h, revealing potential roles in drought tolerance. These findings provide a foundation for further exploration of the functional roles of the maize Snf2 gene family in development and stress responses.

Genome-Wide Analysis of the Nramp Gene Family in Kenaf (Hibiscus cannabinus): Identification, Expression Analysis, and Response to Cadmium Stress.

Kenaf (Hibiscus cannabinu) is a grass bast fiber crop that has the ability to tolerate and accumulate heavy metals, and it has been considered as a potential heavy metal accumulator and remediation plant. Nramp is a natural resistance-related macrophage, which plays an important role in the transport of divalent metal ions, plant growth and development, and abiotic stress. In this study, the Nramp gene family of kenaf was analyzed at the whole genome level. A total of 15 HcNramp genes were identified. They are distributed unevenly on chromosomes. Phylogenetic analysis classified 15 HcNramp proteins into 3 different subfamilies. All proteins share specific motif 4 and motif 6, and the genes belonging to the same subfamily are similar in structure and motif. The promoters are rich in hormone response, meristem expression, and environmental stress response elements. Under different treatments, the expression levels of HcNramp genes vary in different tissues, and most of them are expressed in roots first. These findings can provide a basis for understanding the potential role of the Nramp gene family in kenaf in response to cadmium (Cd) stress, and are of great significance for screening related Cd tolerance genes in kenaf.

Distribution and species composition of potato viruses in the Novosibirsk region.

Among the many diseases that affect potato plants, viral infections are the most common and cause significant damage to farms, affecting both the yield and quality of potatoes. In this regard, an important condition for preserving the potato seed fund in Russia is systematic monitoring and early highly specific detection of potato viral infections. The purpose of the work is to study samples of potato varieties collected in the Novosibirsk region for the presence of viral infections using RT-PCR. 130 potato plants from three districts of the Novosibirsk region (NR) were studied. As a result of monitoring, the following viruses were identified: PVY (potato virus Y), PVS (potato virus S), PVM (potato virus M) and PVX (potato virus X). The quarantine pathogen potato spindle tuber viroid (PSTVd) was not detected in any of the samples analyzed. The maximum frequency of occurrence in the region was noted for three viruses: PVY, PVM and PVS. A significant proportion of the samples were mixed viral infections: the occurrence of the combination of infection PVY + PVM in plants was 25.0 %, and PVY + PVS, 22.6 %. To develop methods for determining the strain affiliation of the studied samples, the nucleotide sequences of the capsid protein genes of 10 Y-virus isolates were sequenced. Phylogenetic analysis of the studied sequences of NR isolates was carried out with a set of sequences of reference strains 261-4, Eu-N, N:O, NE-11, NTNa, NTNb, N-Wi, O, O5, SYR_I, SYR_II and SYR_III retrieved from GenBank. As a result of phylogenetic analysis, it was established that NR viral samples fell into two groups of strains: group 1, which also includes isolates of the reference strains 261-4/SYR_III, and group 2, NTNa. The obtained results of the strain affiliation of NR samples lay the basis for the development of DNA and immunodiagnostic systems for identifying PVY circulating in NR, as well as for elucidating the source and routes of entry of specific virus strains.Key words: Solanum tuberosum; viral infections; RT-PCR; potato Y virus; phylogenetic analysis.

Phylogeography of the ambrosia beetle Euwallacea interjectus (Coleoptera: Curculionidae: Scolytinae): an emerging poplar pest and its Fusarium mutualists from poplar plantations in China.

Native to Asia, Euwallacea interjectus (Blandford) (Coleoptera: Curculionidae: Scolytinae) is a destructive and invasive pest of live trees, and now it has been found in the United States and Argentina. In recent years, this pest appeared in high densities in poplar monocultures from Eastern China (Jiangsu and Shanghai) and Argentina and caused significant poplar mortality. However, the origin of the pests related to tree damage and the Fusarium mutualists from some poplar zones in China remained unclear. Here, we provided a broader phylogeographic analysis of E. interjectus based on the mitochondrial gene (cytochrome c oxidase I) to determine the global genetic structure of this species. Five mitochondrial lineages were found in the native area. Populations introduced to the United States were originated from 4 localities. The Argentine population was derived from Japan. The species was observed with strikingly high level of cytochrome c oxidase I intraspecific divergence that exceeded interspecific divergence, but the high intraspecific variation was correlated with geographical locations among the native populations. Two nuclear genes (arginine kinase and carbamoyl-phosphate synthetase 2-aspartate transcarbamylase-dihydroorotase) were more conservative, and intraspecific differences were lower than interspecific differences. The mitochondrial genetic variation was probably caused by evolution of lineages among geographically isolated populations. But it is immature to infer the existence of cryptic species based on cytochrome c oxidase I differences. All samples collected from poplar populations were indigenous and formed close relationship with a specimen from eastern and southern China. Surprisingly, pests from poplar populations in Jiangsu and Shanghai showed different haplotypes and mutualists. This suggested that the control strategies should consider the genetic and mutualistic diversity of beetles at different poplar localities.

The redescription and complete mitogenomes of two Oxycarenus species (Hemiptera, Oxycarenidae) and phylogenetic implications.

In this study, the two Oxycarenidae species, O.gossypii Horváth, 1926 and Oxycarenusbicolorheraldus Distant, 1904, are redescribed, and their complete mitogenomes are sequenced and analyzed. The phylogeny of Lygaeoidea is examined using 45 complete mitogenomes of lygaeoid species and four outgroup species. The gene orientation and arrangement of the two mitogenomes are found to be consistent with typical Lygaeoidea mitochondrial features, comprising 37 genes, including 13 PCGs, 22 tRNAs, 2 rRNAs, and a control region. Nucleotide composition of the species was biased towards A and T, with the gene order identical to the putative ancestral arrangement of insects. Start codons, stop codons, RNAs, relative synonymous codon usage (RSCU), and nucleotide diversity (Pi) of Oxycarenidae exhibited characteristics similar to other families in Lygaeoidea. Bayesian-inference (BI) and maximum-likelihood (ML) methods were employed to investigate phylogenetic relationships using PCG datasets from selected species. Phylogenetic analyses reveal slightly different topologies between BI and ML methods, with variation primarily concentrated in Colobathristidae and Rhyparochromidae. Our study confirms that the two sequenced Oxycarenidae species formed a single clade, and the position of Oxycarenidae remains stable in both ML and BI phylogenetic trees. These findings expand the mitochondrial genome databases of Lygaeoidea and provide valuable insights into the phylogenetic relationships within Lygaeoidea or Pentatomomorpha.