Soybean cyst nematode (SCN, Heterodera glycines) poses the most devastating biotic threat to global soybean production. Traditional SCN resistance mediated by the Rhg1 locus predominantly relies on gene copy number expansion and elevated α-SNAP protein dosage. Here, we report a novel resistance mechanism in a single-copy rhg1-c background, wherein a C-terminal 24-amino-acid truncation of SNAP18 (designated SNAP18lmm3) triggers a functional switch from vesicular trafficking to autophagic degradation. Biochemical assays and structural modeling demonstrate that this truncation severely impairs the canonical interaction between SNAP18 and N-ethylmaleimide-sensitive factor (NSF), disrupting SNARE complex recycling and inducing localized cytotoxicity. Concomitantly, the truncated SNAP18lmm3 exposes a binding interface for the autophagy-related protein ATG8f, routing the aberrant protein for selective autophagic clearance. This constitutively activated autophagic flux acts as a systemic detoxification system, preventing widespread cell death and ensuring normal plant growth under non-stressed conditions. Upon SCN infection, SNAP18lmm3 specifically hyper-accumulates within nematode-induced syncytia. This accumulation reaches levels fourfold higher than in adjacent cells, which overwhelms the local autophagic capacity and triggering targeted cell death that arrests nematode development. By elucidating this competitive molecular switch between NSF and ATG8f binding, our study establishes a "self-degrading toxin" model that resolves the inherent trade-off between plant growth and immunity. This work provides a new theoretical framework for engineering cellular homeostasis to enhance durable crop resistance against parasitic nematodes.

Soybean cyst nematode (Heterodera glycines, SCN) and southern root-knot nematode (Meloidogyne incognita, RKN) are major limitation to soybean production, with few resistance sources available. Using 199 and 177 chromosome segment substitution lines (CSSLs) derived from Glycine max cv. Suinong14 and G. soja accession ZYD00006, we evaluated resistance to SCN HG type 1.2.3.5.6.7 (race 4) and RKN race 1, and compared the loci with those previously mapped for SCN HG type 2.5.7 (race 5). Despite both parents being susceptible, many CSSLs exhibited resistance levels exceeding both parents, while others showed extreme susceptibility, demonstrating strong transgressive segregation. QTL mapping identified 6 FI-associated and 9 CGR-associated loci for SCN race 4, and 17–25 significant loci for RKN across two inoculum levels. Single resistance loci generally conferred only moderate effects, but the combination of multiple favorable alleles from both parents produced higher resistance. Comparative analysis revealed several shared QTL intervals among SCN races 4 and 5 and RKN race 1, suggesting partial common genetic control. These findings demonstrate that pyramiding multiple loci from wild and cultivated soybean can generate transgressive inheritance, producing resistant lines beyond parental performance and offering valuable targets for breeding durable, broad-spectrum nematode resistance.

The soybean cyst nematode (SCN, Heterodera glycines) relies on chemosensation for host localization and successful infection. Understanding the molecular basis of chemosensation is critical, as it determines the nematode's ability to locate and invade host roots. In the model nematode Caenorhabditis elegans, Transient Receptor Potential Vanilloid (TRPV) channels osm-9 and ocr-2 and the G-protein α subunit goa-1 mediate sensory perception and ion transport; however, their roles in SCN remain largely unexplored. Here, we cloned and characterized these three candidate genes, which showed predominant expression in the phasmids of preparasitic juveniles. RNA interference revealed distinct roles: Hg-goa-1 regulated locomotion, whereas Hg-osm-9 and Hg-ocr-2 controlled chemotaxis, particularly attraction under acidic and basic conditions. Silencing any gene reduced root penetration and reproduction, while gene interaction analyses suggested a cross-regulatory network. Collectively, these results identify the three genes as essential regulators of SCN chemosensation, locomotion, and parasitism, providing potential molecular targets for developing species-specific nematicides.

Understanding the molecular and metabolic interplay between Meloidogyne incognita and soybean (Glycine max) root exudates is essential for unraveling plant-nematode interactions. This study investigates the transcriptomic responses of M. incognita during the preparasitic stage and the metabolomic changes in soybean root exudates influenced by nematode activity. Transcriptomic analysis identified 846 differentially expressed genes in nematodes exposed to root exudates (S-Mi) compared with nematodes alone (Mi). Upregulated genes, including those encoding sensory receptors such as G-protein-coupled receptors, nuclear hormone receptors, acetylcholine receptors, and key effectors, indicate a shift toward parasitic readiness. The downregulation of detoxification genes (e.g., cytochrome P450) and the upregulation of lysosome-related genes, such as cathepsins L-like cysteine proteases suggest metabolic reprogramming to support infection. Metabolomic profiling identified 781 metabolites across S-Mi, Mi, and Soy (root exudates alone), with enriched pathways such as tyrosine metabolism and cytochrome P450-related detoxification. Interestingly, amino acids such as L-threonine and arginylthreonine were upregulated in S-Mi, suggesting their role in nematode attraction. Additionally, lipid-like metabolites, such as 3-epipapyriferic acid and physagulin F, were elevated, potentially influencing nematode behavior and modulating plant defense response. An integrated cellular model illustrates how nematode sensory receptors detect root signals, activating cyclic adenosine monophosphate, phospholipase C, and mitogen-activated protein kinase signaling cascades, as well as acetylcholine receptor-mediated ion channels, leading to effector gene activation and metabolic shifts. This study reveals a bidirectional interaction at the preparasitic stage, where soybean root exudates reprogram nematode metabolism, and nematodes, in turn, modify root exudates to influence plant defenses, offering novel targets for sustainable nematode management.

Unraveling the intricacies of soybean cyst nematode (Heterodera glycines) race 4 resistance and susceptibility in soybean breeding lines-11-452 (highly resistant) and Dongsheng1 (DS1, highly susceptible)-was the focal point of this study. Employing cutting-edge N6-methyladenosine (m6A) and RNA sequencing techniques, we delved into the impact of m6A modification on gene expression and plant defense responses. Through the evaluation of nematode development in both resistant and susceptible roots, a pivotal time point (3 days postinoculation) for m6A methylation sequencing was identified. Our sequencing data exhibited robust statistics, successful soybean genome mapping, and prevalent m6A peak distributions, primarily in the 3' untranslated region and stop codon regions. Analysis of differential methylation peaks and differentially expressed genes revealed distinctive patterns between resistant and susceptible genotypes. In the highly resistant line (11-452), key resistance and defense-associated genes displayed increased expression coupled with inhibited methylation, encompassing crucial players such as R genes, receptor kinases, and transcription factors. Conversely, the highly susceptible DS1 line exhibited heightened expression correlated with decreased methylation in genes linked to susceptibility pathways, including Mildew Locus O-like proteins and regulatory elements affecting defense mechanisms. Genome-wide assessments, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses, and differential methylation peak/differentially expressed gene overlap emphasized the intricate interplay of m6A modifications, alternative splicing, microRNA, and gene regulation in plant defense. Protein-protein interaction networks illuminated defense-pivotal genes, delineating divergent mechanisms in resistant and susceptible responses. This study sheds light on the dynamic correlation between methylation, splicing, and gene expression, providing profound insights into plant responses to nematode infection.

Summary Entomopathogenic nematodes (EPN) as an environmentally-friendly biocontrol agent in combination with low toxic insecticides can increase control efficacy against insect pests. In this study, Steinernema carpocapsae All (Sc-All) combined with four common insecticides was used to evaluate the control efficacy against chive root gnat (Bradysia odoriphaga), an important pest of vegetables, e.g., chive, onion or garlic. The compatibility of nematodes with insecticides and host-seeking behaviour were also evaluated by the laboratory bioassay. The results showed three insecticides (matrine, imidacloprid and chlorpyrifos) at the recommended concentrations (RC), 10% RC or 2% RC and insecticide phoxim at 10% RC or 2% RC had no effect on nematodes survival. Sc-All at 50 infective juveniles (IJ) per insect larva in the presence of the four insecticides at 10% RC demonstrated a potentiated, additive or a synergistic effect on the corrected mortality rates of insect up to 100% (imidacloprid) when compared with the corresponding insecticide and Sc-All alone. A synergistic effect resulting in lethal effect was found as early as at 24 h when 200 IJ of Sc-All per insect larva were combined with 10% RC imidacloprid, whilst only 9.4% and 0 corrected mortality were detected, respectively, when exposed to the same amount of imidacloprid and Sc-All alone. For the first time a Pluronic gel system assay revealed that the presence of insecticides significantly improved Sc-All host-seeking ability as early as 30 min post exposure. The results indicated that low doses of Sc-All-imidacloprid combination would be an effective strategy to control chive root gnat.

'Baiwei' (swallowwort root, Cynanchum versicolor Bunge), is a perennial cranberry type of Chinese medicinal herb, and grows in mountains with wide distribution in many provinces including Shandong, Henan, Hebei, Liaoning, Anhui and others. The functions of 'Baiwei' are strengthening myocardial contraction, detoxifying, and as a diuretic; thus it is one of very important herbs in China (Yunsi Su et al. 2021). With the increasing need for this herbal medicine in China, farmers are trying to cultivate the wild type of 'Baiwei'. In 2019, we found severe crop damage in a second-year planting of 'Baiwei' with many dead plants in a field (Fig. S1A, B) in Mengyin County of Shandong Province, China. Root galls were clearly seen in the roots and the typical root-knot nematode (Meloidogyne spp.) symptoms were observed (Fig. S1C). The previous crop was peanut. Peanut is widely planted in Shandong Province and peanut root-knot nematode (M. arenaria) is one of its major root-knot nematode pests. We suspected that the damage was caused by peanut root-knot nematode. The roots were taken to the lab and kept at 10℃ for morphological and molecular identification of root-knot nematodes, and pathogenicity testing. Twenty females were picked up from the infected roots for perineal pattern observation. The perineal pattern had distinct characteristics such as a low dorsal arch and lateral field marked by forked and broken striae and without punctate markings between the anus and tail terminus (Fig. S2A), which is similar to the description of M. arenaria (Eisenback et al., 1981). Eggs were extracted from roots and hatched to second-stage juveniles (J2s). The morphometric characters of J2s (n = 30) demonstrated body length = 437.35 ± SE 3.51 µm, body width = 16.74 ± 0.16 µm, stylet length = 11.31 ± 0.20 µm, DGO = 3.87 ± 0.07 µm, tail length = 53.32 ± 0.99 µm, and hyaline tail terminus = 11.14 ± 0.12 µm. The universal primer 194/195 (5.8S-18S rDNA TTAACTTGCCAGATCGGACG/TCTAATGAGCCGTACGC) for confirmation of Meloidogyne spp. was chosen and the sequence characterized amplified region (SCAR) PCR specific markers for M. incognita (Finc/Rinc GGGATGTGTAAATGCTCCTG/CCCGCTACACCCTCAACTTC), M. javanica (Fjav/Rjav ACGCTAGAATTCGACCCTGG/GGTACCAGAAGCAGCCATGC), M. enterolobii (Fent/Rent GAAATTGCTTTATTGTTACTAAG/TAGCCACAGCAAAATAGTTTTC), M. arenaria (Fare/Rare TCGGCGATAGAGGTAAATGAC/TCGGCGATAGACACTACAACT), M. hapla (Fhap/Rhap TGACGGCGGTGAGTGCGA/TGACGGCGGTACCTCATAG) and M. chitwoodi (Fchi/Rchi TGGAGAGCAGCAGGAGAAAGA/GGTCTGAGTGAGGACAAGAGTA) were utilized for species identification (Mao et al., 2019). PCR products of J2 amplification were run in the agar gel (Fig. S2B). A PCR product of 750 bp was obtained for 194/195 primer pair and a 420 bp band was identified for M. arenaria for all tested J2 samples. There were no bands for other specific primers. The amplicons from 194/195 and M. arenaria primer pairs were sequenced. A 100% identity of the Fare/Rare sequence (MZ522722.1) with M. arenaria KP234264.1 and a 99.8% identity with M. arenaria MW315990.1 were found through NCBI blast. A 100% identity of the 194/195 sequence (MZ555753.1) with both M. arenaria GQ395518.1 and U42342.1 and M. thailandica HF568829.1. To confirm the pathogenicity, 2000 J2s obtained from the same population as described above were used to inoculate each plant of one-month old 'Baiwei' seedlings (n = 5) and of one-month-old tomato cv. 'Zhongshu4' seedlings (n = 5) growing in 15-cm-diameter and 10-cm-height plastic pot containing sand and soil (2:1 ratio) in the glasshouse at 22-28℃ and 16/8 h day/night. Plants without J2s were used as control. Sixty days later, roots were stained with erioglaucine (Omwega et al. 1988) and an average of 107 ± SE 59 and 276 ± SE 31 egg masses per gram root were produced in each infected 'Baiwei' (Fig. S3A) and tomato (Fig. S3B) root, respectively. PCR amplification of the hatched J2s reconfirmed the reproduced nematode in 'Baiwei' and tomato was M. arenaria. This is the first report on M. arenaria parasitizing the medicinal herb C. versicolor in China.

Soybean cyst nematode (Heterodera glycines Ichinohe),a devastating pathogen in soybean, was chosen as a model system toinvestigate nematode behavior and gene expression changes in responseto acidic and basic pH and salt signals (pH 4.5, 5.25, 8.6, and 10and NaCl) through full-length transcriptome sequencing of 18 samples.An average of 4.36 Gbp of clean reads per sample were generated, and3972 novel genes and 29,529 novel transcripts were identified. Sequencestructural variation during or after transcription may be associatedwith the nematode's behavioral response. The functional analysisof 1817/4962 differentially expressed genes/transcripts showed thatsignal transduction pathways, including transmembrane receptors, ionchannels, and Ca2+ transporters, were activated, but pathwaysinvolved in nematode development (e.g., ribosome) and energy production(e.g., oxidative phosphorylation) were inhibited. A correspondingmodel was established. Our findings suggest that these receptors andion channels might be potential targets for nematicides or drug discovery.

我国植物寄生线虫病已经发展成仅次于真菌病害的第二大植物病害,防治难度极大.随着我国农业可持续发展的需求,一些高毒高效化学农药不断被禁用,导致可供选择化学杀线虫剂的产品非常有限,进而杀线植物资源备受广大线虫学者的关注.本文综述了具有杀线虫作用的植物资源,如根系分泌物、组织提取物等活性物质,对植物寄生线虫的作用机制及生产实践中对这些资源的应用情况,并针对目前存在的问题和对未来的研究趋势提出了展望,以期为具有杀线虫作用的植物及其资源的开发和应用提供材料、思路和理论依据.

Due to their tiny size, soil nematodes and plant-parasitic nematodes are challenging to homogenize and collect using traditional mortar and pestle methods. To overcome this, we developed a reliable and efficient nematode preparation and grinding method using the BioPulverizer. The method involves creating a modified sample ‘sandwich’ with liquid nitrogen-frozen nematode samples placed between two layers of aluminum foil. This ‘sandwich’ facilitates complete homogenization through cryogenic grinding without any sample loss during transfer. The powerful nematode grinding yields high-quality and high-quantity samples, suitable for nucleic acid release and subsequent molecular identification and other downstream applications.

为了调查山东省临沂地区中草药根结线虫(Meloidogyne spp.)的种类,对临沂地区的蒙阴县和平邑县7个发病丹参田采集丹参样品,并分离线虫,利用根结线虫的通用引物(rDNA-ITS区域194/195)和常见根结线虫种的特异性引物对二龄幼虫进行分子鉴定,对PCR产物及其序列比较分析进而确定线虫种类,同时确定这些线虫能否在番茄上繁殖,然后对确定线虫种类的二龄幼虫形态学和雌虫会阴花纹的特征进行了鉴定.结果表明,rDNA-ITS区域194/195通用引物对所有7个样品都扩增出750 bp产物,证明是根结线虫,序列之间的相似度范围是99.4％ ～100％;序列特异性引物扩增表明蒙阴县4个样品是花生根结线虫(M.arenaria),2个样品是南方根结线虫(M.incognita),平邑县1个样品是南方根结线虫.序列分别与已报道的花生根结线虫和南方根结线虫100％同源,通用引物扩增产物序列也分别与基因库中这两种线虫序列达到98.3％ ～100％相似性.所有样品线虫都能在番茄上繁殖,二龄幼虫的形态学特征和雌虫会阴花纹的特征与已鉴定的南方根结线虫和花生根结线虫的特征相同.

大豆孢囊线虫(Heterodera glycines Ichinohe)病是大豆生产上重要经济病害之一.东北地区作为我国大豆主产区,大豆种植面积增加同时该地区病害呈逐年加重趋势.为有效防控大豆孢囊线虫病,文章阐述东北地区大豆孢囊线虫生理小种种类、分布和变异及病害发生程度等规律.根据该区大豆孢囊线虫病害发生特点综述已有防控技术研究进展,主要包括农业措施、化学防治、生物防治、利用抗病品种等.最后展望未来潜在防控技术,以期为东北地区大豆丰产和农业可持续发展提供理论依据和技术支撑.

Plant-parasitic nematode infective juveniles (J2) use phytochemical signals released into the rhizosphere to locate host roots. Amino acids are the second most abundant metabolites of root exudates, but it is unknown if they are associated with J2 chemotaxis. In this study, J2 chemotaxis and mortality of the soybean cyst nematode (Heterodera glycines) and root-knot nematodes (Meloidogyne incognita and M. hapla) were examined in response to 15 amino acids and the corresponding pH values for tested amino acid solutions were measured. Responses varied by amino acid and among the species. Significant attraction, determined by J2 count within amino acid solution dispensers after 24 h exposure, occurred with 19 out of 45 J2-amino acid combinations. Heterodera glycines, M. hapla and M. incognita were attracted to nine, three and seven amino acids, respectively. Strongest attractions were to acidic polar amino acids aspartate and glutamate (H. glycines, M. hapla) and basic polar arginine (M. hapla), as previously reported, acid and basic pH attracting nematodes, thereby indicating that pH might be one of the attraction factors for these amino acids. All three nematodes exhibited clustering behaviours, such as halo or balling formations, just outside amino acid solution dispensers, with H. glycines, M. hapla and M. incognita responding to four, 12 and two amino acids, respectively. Six of 15 amino acid solutions, representing a range of pH values, caused increased mortality. Certain aspartate and glutamate affected both H. glycines and M. hapla; arginine, aspartate, cysteine, lysine, methionine affected M. incognita; and cysteine caused complete mortality in M. hapla. All the results suggest that amino acids affect nematode attraction and mortality.

根结线虫病是番茄(Solanum lycopersicum L.)生产中一重要病害,为了筛选抗病品种,采用温室盆栽人工定量接种法,鉴定了黑龙江省21个番茄栽培品种对南方根结线虫(Meloidogyne incognita)的抗感反应,并且对筛选到的抗性品种接种北方根结线虫(M.hapla),以验证抗性品种是否含有抗南方根结线虫的Mi基因.结果表明,抗性对照VFNT对南方根结线虫表现为免疫,参试品种只有红春桃和水果番茄的病情指数表现为抗病,分别为12和20;红春桃和水果番茄对南方根结线虫繁殖参数(卵块数和卵的繁殖系数)分别为免疫和抗病,其它品种都表现为感病或高感;红春桃和水果番茄2个品种与VFNT一样对北方根结线虫均表现为感病,说明红春桃和水果番茄品种含有和VFNT一样的Mi-1基因.该研究从当地筛选出的红春桃和水果番茄为防治番茄南方根结线虫病提供有价值的抗病材料;同时,可以看出市售的多数番茄为感病甚至高感品种,这将给番茄根结线虫病的防治带来巨大困难.

Full-length transcriptome sequencing with long reads is a powerful tool to analyze transcriptional and post-transcriptional events; however, it has not been applied on soybean (Glycine max). Here, a comparative full-length transcriptome analysis was performed on soybean genotype 09-138 infected with soybean cyst nematode (SCN, Heterodera glycines) race 4 (SCN4, incompatible reaction) and race 5 (SCN5, compatible reaction) using Oxford Nanopore Technology. Each of 9 full-length samples collected 8 days post inoculation with/without nematodes generated an average of 6.1 GB of clean data and a total of 65,038 transcript sequences. After redundant transcripts were removed, 1,117 novel genes and 41,096 novel transcripts were identified. By analyzing the sequence structure of the novel transcripts, a total of 28,759 complete open reading frame (ORF) sequences, 5,337 transcription factors, 288 long non-coding RNAs, and 40,090 novel transcripts with function annotation were predicted. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses of differentially expressed genes (DEGs) revealed that growth hormone, auxin-activated signaling pathway and multidimensional cell growth, and phenylpropanoid biosynthesis pathway were enriched by infection with both nematode races. More DEGs associated with stress response elements, plant-hormone signaling transduction pathway, and plant-pathogen interaction pathway with more upregulation were found in the incompatible reaction with SCN4 infection, and more DEGs with more upregulation involved in cell wall modification and carbohydrate bioprocess were detected in the compatible reaction with SCN5 infection when compared with each other. Among them, overlapping DEGs with a quantitative difference was triggered. The combination of protein-protein interaction with DEGs for the first time indicated that nematode infection activated the interactions between transcription factor WRKY and VQ (valine-glutamine motif) to contribute to soybean defense. The knowledge of the SCN-soybean interaction mechanism as a model will present more understanding of other plant-nematode interactions.

Summary Soybean cyst nematode (SCN, Heterodera glycines) is a devastating plant-parasitic nematode worldwide. Two SCN races, race 4 (HG Type 1.2.3.5.6.7) and race 5 (HG Type 2.5.7), with increased virulence were previously identified in Northeast China. To obtain new resistance sources to these SCN populations, the response of 62 genotypes, including 51 local varieties and breeding lines, and 11 indicator lines for SCN race and HG Type identification, were evaluated. Four new primers in the regions of two loci of GmSHMT08 (Rhg4) and GmSNAP18 (rhg1) were designed for PCR amplification and subsequent sequencing to characterise haplotypes instead of genome resequencing. Results indicated three haplotypes among 51 local genotypes; there were 26 lines in Haplotype I carrying both the rhg1-a and Rhg4-a resistant loci as in ‘Peking’, 13 lines in Haplotype II containing only the resistant rhg1-a locus but Rhg4-b susceptible loci, and 12 lines in Haplotype III with rhg1-c and Rhg4-b susceptible loci. Interestingly, there was no ‘PI 88788’-type resistance identified in Northeast China, although it accounts for 90% of sources in the USA. Two local breeding lines in Haplotype I displayed resistance to both SCN races. The resistance lines carried higher copy number (>1) of the tandem duplication at the rhg1 locus compared with susceptible lines (⩽1). The combination of the two microsatellite markers, Sat_162 on Chr 8 and 590 on Chr 18, distinguished the three haplotypes and predicted the resistance/susceptibility for SCN race 5. The knowledge of the phenotypes and molecular characteristics of 51 local breeding lines in Northeast China will accelerate the utilisation of sources for broad-based SCN resistance and marker-assisted selection.

Chromosome segment substitution lines (CSSLs) are valuable genetic resources for quantitative trait loci (QTL) mapping of complex agronomic traits especially suitable for minor effect QTL. Here, 162 BC3F7-BC7F3 CSSLs derived from crossing two susceptible parent lines, soybean [Glycine max (L.) Merr.] 'Suinong14' (recurrent parent) x wild soybean (G. soja Siebold & Zucc.) ZYD00006, were used for QTL mapping of soybean cyst nematode (SCN, Heterodera glycine Ichinohe) resistance based on female index (FI) and cysts per gram root (CGR) through phenotypic screening and whole-genome resequencing of CSSLs. Phenotypic results displayed a wide range of distribution and transgressive lines in both HG Type 2.5.7 FI and CGR and demonstrated a higher correlation between CGR and root weight (R-2 = .5424) compared with than between FI and CGR (R-2 = .0018). Using the singlemarker analysis nonparametric mapping test, 33 significant QTL were detected on 18 chromosomes contributing resistance to FI and CGR. Fourteen QTL contributing 5.6-15.5% phenotypic variance (PVE) to FI were revealed on 11 chromosomes, and 16 QTL accounting for 6.1-36.2% PVE in CGR were detected on 14 chromosomes with strong additive effect by multiple-QTL model (MQM) mapping. Twenty-five and 13 out of all 38 QTL identified for FI and CGR on 20 chromosomes were from ZYD00006 and Suinong14, respectively. The CSSLs with the combination of positive alleles for FI, CGR, and root weight exhibited low nematode reproduction. For the first time, QTL associated with CGR have been detected, and both FI and CGR should be considered for breeding purposes in the absence of strong resistance genes such as rhg1 and Rhg4.

为了快速鉴定昆虫病原线虫,同时验证实验室多年保存的昆虫病原线虫种或品系间的差异,采用线虫保守区间核糖体DNA(rDNA,18S-ITS1-5.8S-ITS2-28S)的PCR扩增和测序分子鉴定方法,对13个线虫种和品系的18S-28S rDNA和28S rDNA(D2-D3)进行扩增并对序列进行比较和分析,研究斯氏属(Steinernema)和异小杆属(Heterorhabditis)线虫的rDNA保守区域是否和已报道的线虫相同.结果表明,28S rDNA的D2-D3的扩增序列比对的分子数据和形态学鉴定的结果完全一致,且与基因库已报道的线虫种相似度达到99％ ～100％,能明显区分线虫属、种或者品系.18S-ITS1-5.8S的序列能够区分S.glaseri和S.carpocapsae,但不能区分序列相近的S.litorale和S.feltiae,需要内转录间隔区ITS2来区分.因此,rDNA能被用于快速分类鉴定昆虫病原线虫的种和品系.