For sedentary endo-parasitic nematodes, parasitism genes encoding secretory protein expressed in the subventral glands cells always play an important role during the early parasitic process. A new acid phosphatase gene (Ha-acp1) expressed in the subventral glands of the cereal cyst nematode (Heterodera avenae) was cloned and the characteristics of the gene were analyzed. Results showed that the gene had a putative signal peptide for secretion and in situ hybridization showed that the transcripts of Ha-acp1 accumulated specifically in the subventral gland cells of H. avenae. Southern blot analysis suggested that Ha-acp1 belonged to a multigene family. RT-PCR analysis indicated that this transcription was strong at the pre-parasitic juveniles. Knocking down Ha-acp1 using RNA interference technology could reduce nematode infectivity by 50%, and suppress the development of cyst. Results indicated that Ha-acp1 could play an important role in destroying the defense system of host plants.

The cereal cyst nematode (CCN, Heteroder aavenae) causes serious yield loss on cereal crops, especially wheat, worldwide. Daxing population in Beijing City and Huangyuan population in Qinghai Province, China, are two CCN populations. In this study, the CCN pathotypes of Daxing and Huangyuan populations were characterized by tests on 23 standard “International Test Assortment” with the local species Wenmai 19 as the susceptible control. Tested materials were grouped by three nematode populations’ virulence on resistant genes (Rha1, Rha2, Rha3, Cre1) and nonresistant genes, varieties and lines. Both Daxing and Huangyuan populations were avirulent to Ortolan (Ha1). Barley cvs. Ortolan, Siri, Morocco, Bajo Aragon 1-1, and Martin 403-2 were all resistant to both populations. Cultivars Herta, Harlan 43 and wheat Iskamish-K-2-light were all susceptible to Huangyuan population, all of them, however, were resistant to Daxing population. The other five oats were all resistant to the two tested CCN populations. Except Iskamisch K-2-light, all the other wheat cultivars (Capa, Loros×Koga, AUS 10894, and Psathias) were susceptible to Daxing population. Because the pathotypes of the two tested CCN populations in Beijing and Qinghai were not identical to any of the 13 pathotypes previously characterized by the test assortment, we classified Daxing and Huangyuan populations as the new pathotypes, named Ha91.

Ten populations of Radopholus similis from different ornamental hosts were tested for their parasitism and pathogenicity to water spinach (Ipomoea aquatic), malabar spinach (Basella rubra), and squash (Cucurbita moschata) in pots. The results showed all three plants were new hosts of R. similis. Growth parameters of plants inoculated with nematodes were significantly lower than those of healthy control plants. All R. similis populations were pathogenic to the three plants, but pathogenicity differed among populations from different hosts. The same R. similis populations also showed different pathogenic effects in the three different plants. RadN5 population from Anthurium andraeanum had the highest pathogenicity to the three studied plants. RadN1 from A. andraeanum had the lowest pathogenicity to squash and RadN7 from Chrysalidocarpus lutesens had the lowest pathogenicity to water spinach and malabar spinach. R. similis is usually associated with root tissues, but here we report that it could be found to move and feed in the stem bases of all three studied plants. Sequence and phylogenetic analyses of DNA markers of the 18S rRNA, 28S rRNA, ITS rRNA, and mitochondrial DNA gene sequences of ten R. similis populations revealed significant genetic diversity. RadN5 and RadN6 populations from anthurium showed a close genetic relationship and could be distinguished from other populations by PCR-RFLP. At the same time, RadN5 and RadN6 populations were the most pathogenic to three studied plants. These results confirm the existence of large biological variability and molecular diversity among R. similis populations from the same or different hosts, and these characteristics are related to pathogenic variability.

Soybean cyst nematode Heterodera glycines is one of the most serious soil-borne pathogens in soybean production. However, the researches were limited in China due to lack of an effective pathosystem. In this study, we screened 21 legume Medicago plants in both Medicago truncatula and Medicago sativa to obtain candidate model plants for establishing a new pathosystem for legume-H. glycines interactions. The nematode infection of tested plants was assayed with Race 3 and 4 respectively, which were two dominant H. glycines inbred races in China soybean producing areas. The results showed that the model legume plant M. truncatula A17 failed to allow Race 3 of H. glycines to complete its life cycle, in contrast, it provided the Race 4 population to form several cyst nematodes, however, the female index (FI) value was approximately 1.6. Three M. sativa cultivars, including Xunlu, Aergangjin and Junren, provided either Race 3 or 4 of H. glycines to develop into mature cysts with their FI value below 5 as well. Our results demonstrated that legume plants in both M. truncatula and M. sativa were not likely to be a model plant for H. glycines because of an extreme high resistance.

The cereal cyst nematode, Heterodera avenae Wollenweber, 1924, is a major pest of cereal crops throughout the world and causes serious yield losses, especially of wheat.  Previous studies have shown that this species is widely distributed in the Czech Republic.  In this study, seven populations of H. avenae were molecularly studied, and one population was morphologically described.  Three regions (18S, 28S, and internal transcribed spacer 1) of ribosomal DNA were sequenced and the analysis of the 18S gene of six populations did not reveal any variation, whereas the internal transcribed spacer 1 and 28S sequences of six populations differed by only two nucleotides from a population in ?ilina.  Precise and quick identification of cereal cyst nematodes is important for effective control measures and ribosomal sequence analyses of seven populations in this study will be useful in future phylogenetic studies of Heterodera spp. occurring in the Czech Republic.

Streptomyces rubrogriseus HDZ-9-47, isolated from eggs of Meloidogyne spp., was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.  Microscopic observations showed that HDZ-9-47 parasitized eggs of M. incognita within 7 days.  In vitro, the culture filtrate of HDZ-9-47 caused 97.0% mortality of second-stage juveniles (J2s) of M. incognita and inhibited more than 50% egg hatching.  In the field, compared with the control, the root-knot index and J2s density in the treatment of drench the broth contained 10¹² HDZ-9-47 spores were respectively reduced by 51.1 and 80.7% at 90 days post transplantation, which were better than that in other application doses and methods.  In addition, reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%, respectively, better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.  And tomato yield also increased by 16.1%.  Together, our results suggest that HDZ-9-47 could be an effective biocontrol agent of M. incognita, and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M. incognita control.

    Heterodera avenae (cereal cyst nematode, CCN) infects many cereal crops and causes serious yield losses worldwide. Interaction studies investigating H. avenae and its hosts are still in their infancy. In this study, a barley model plant, the Hordeum vulgare cultivar Golden Promise, was investigated for its potential as a candidate model host to study its interaction with H. avenae. CCN-infective juveniles were attracted by the root tips and gathered around the root elongation zones of Golden Promise on 0.7% water agar plates. The juveniles invaded the roots and developed successfully until maturation at 40 days after inoculation in sterile sand soil. The cryotomy and syncytium measurements indicated that the syncytia enlarged gradually throughout the development of the nematodes and caused the corresponding root regions to swell obviously. Quantitative real-time PCR analysis showed that the down-regulation of defence-related barley genes and up-regulation of development-related barley genes contribute to the understanding of compatible interaction between H. avenae and Golden Promise. Barley stripe mosaic virus (BSMV) virus-induced gene silencing (VIGS) can be used in the roots of Golden Promise. In conclusion, the Hordeum vulgare cultivar Golden Promise is a suitable candidate model host for interaction studies with Heterodera avenae. The studies presented above document the first CCN host that not only has published genome context but also be compatible to BSMV VIGS.  

Plant-parasitic nematodes are very common on cereal crops and cause economic losses via reduction in grain quality and quantity. During 2014, 83 soil samples were collected from wheat and barley fields in 21 districts of 13 provinces across five regions (Central Anatolia, Marmara, Aegean, Southeast Anatolia, and Black Sea Region) of Turkey. Cyst-forming nematodes were found in 66 samples (80%), and the internal transcribed spacer (ITS) sequencing and species-specific PCR identified the species in 64 samples as Heterodera filipjevi, Heterodera latipons, and Heterodera avenae. The predominant pathogenic cereal cyst nematode was H. filipjevi, which was found in all five regions surveyed. H. avenae was only detected in Southeast Anatolia whereas H. latipons was detected in Southeast Anatolia and Central Anatolia. ITS-rDNA phylogenetic analyses showed that H. avenae isolates from China clustered with H. australis, and Turkish isolates were closely related to European and USA isolates of this species. H. filipjevi from Turkey and China were clustered closely with those from the UK, Germany, Russia, and the USA. The density of many of these populations exceeded or approached the maximum threshold level for economic loss. To our knowledge, this is the first report of H. filipjevi in Diyarbakir, Edirne, and Kutahya provinces, and the first report of H. avenae in Diyarbakir Province. These results exhibit the most rigorous analysis to date on the occurrence and distribution of Heterodera spp. in Turkey’s major wheat-producing areas, thus providing a basis for more specific resistance breeding, as well as other management practices.

Chinese leek (Allium tuberosum Rottler ex Sprengel) is a common vegetable in China.  In our previous study, Chinese leek in rotation was found to have significant antifungal and nematicidal activity.  This study’s aim was to investigate the potential antifungal and nematicidal activity associated with rhizosphere or endophytic microbes of Chinese leek.  Thus, a total of 79 261 high-quality sequences were obtained from Chinese leek rhizosphere soil, leaf and root samples.  In the rhizosphere soil, the bacterial community comprised five dominant phyla: Proteobacteria (37.85%), Acidobacteria (10.99%), Bacteroidetes (8.24%), Cyanobacteria (7.79%) and Planctomycetes (7.1%).  The leaf and root bacterial communities comprised two dominant phyla: Cyanobacteria (83.42% in leaf and 75.44% in root) and Proteobacteria (14.75% in leaf and 21.04% in root).  Microbial diversity, richness and evenness in the rhizosphere soil bacterial community were higher than that in the endophytic bacterial communities.  The rhizosphere bacterial community was significantly different from the endophytic bacterial communities.  The endophytic bacterial communities from the leaf and the root were slightly, but not significantly different from each other.  This study’s findings would contribute to the isolation and identification of nematicidal and antifungal bacterial communities in Chinese leek.

Cereal cyst nematode (Heterodera avenae, CCN) distributes worldwide and has caused severe damage to cereal crops, and a model host will greatly aid in the study of this nematode.  In this research, we assessed the sensitivity of 25 inbred lines of Brachypodium distachyon to H. avenae from Beijing, China.  All lines of B. distachyon were infested by second-stage juveniles (J2s) of H. avenae from Daxing District of Beijing population, but only 13 inbred lines reproduced 0.2–3 cysts/plant, showing resistance.  The entire root system of the infested B. distachyon appeared smaller and the fibrous roots were shorter and less numerous.  We found that a dose of 1 000 J2s of H. avenae was sufficient for nematode infestation.  We showed that Koz-1 of B. distachyon could reproduce more cysts than TR2A line.  Line Koz-1 also supported the complete life cycles of 5 CCN geographical populations belonging to the Ha1 or Ha3 pathotype group.  Our results suggest that B. distachyon is a host for CCN.

The root-knot nematode Meloidogyne graminicola, which is distributed worldwide, is considered a major constraint on rice production in Asia.  The present study used the root gall index and number of nematodes inside the roots to evaluate resistance/susceptibility to M. graminicola in different subpopulations of Oryza sativa (aus, hybrid aus, indica, hybrid indica, temperate japonica, tropical japonica).  Nematode development in highly resistant varieties was also evaluated.  Analyses of randomly selected 35 varieties showed the number of M. graminicola nematodes inside the roots correlated very strongly (r=0.87, P≤0.05) with the nematode gall index, and the results from pot and field experiments revealed similar rankings of the varieties for resistance/susceptibility.  Among the 136 tested varieties, temperate japonica displayed the highest gall index, followed by tropical japonica, indica, hybrid indica, aus, and hybrid aus. Zhonghua 11 (aus), Shenliangyou 1 (hybrid aus) and Cliangyou 4418 (hybrid indica) were highly resistant to M. graminicola under both pot and field conditions.  Further examination of nematode development suggested that compared to susceptible rice, M. graminicola penetrated less often into highly resistant varieties and more frequently failed to develop into females.  The promising varieties found in the present research might be useful for the breeding of hybrid rice in China and for the further development of practical nematode management measures.   

Received  3 March, 2018    Accepted  2 April, 2018

植物寄生线虫是重要的致病性线虫，严重威胁着农业的可持续发展，每年给全球农业造成巨大的经济损失。防治植物寄生线虫的方法主要有培育抗病新品种、种植前土壤消毒、轮作、改变种植时间、休耕等。在诸多策略中，施用杀线虫剂是防治植物寄生线虫的有效方法之一。然而，杀线虫剂长期的重复使用增加了线虫产生抗药性的风险。随着人们环保意识的不断提高，高毒杀线虫剂已不符合现代农业的可持续发展。传统的杀线虫剂噻唑磷和阿维菌素因其对环境和人类健康的不利影响，在未来将会受到越来越多限制。当前，世界范围内植物线虫危害频发，导致杀线虫剂市场价值逐年增加，而杀线虫剂仍然面临着种类少和监管压力大的问题。因此，创制出高效、低风险的新型杀线虫剂是当前线虫综合防治所面临的巨大挑战。天然产物广泛存在于动物、植物和微生物中，它们具有广谱的生物活性，为人们提供多种多样的化学结构模型。许多农药或先导化合物都是天然产物，例如阿维菌素、鱼藤酮、乙蒜素、香兰素、肉桂酸和丁香酚等。由于一些天然产物具有独特的骨架结构、良好的药效基团和广谱的生物活性等诸多优势，近年来引起了药物开发者的广泛关注。研究人员在天然产物的分离和杀线虫线虫活性研究方面做了大量的工作。本工作综述了近10年来醇、酚、醛、酮、酸、酯、酰胺、生物碱、萜和多肽等天然杀线虫活性化合物的研究进展，从天然产物的来源、构效关系和作用机理等方面进行了分类讨论。然后，在天然产物开发和应用的基础上，展望了天然产物杀线虫剂的发展前景，旨在为新型杀线虫剂的发现提供新的思路和启发。

为明确我国主要甜菜产区线虫的种类和危害程度，2015-2018年我们对我国甜菜主要产区进行了系统的调查和检测。在新疆伊犁州新源县的甜菜地调查发现，部分区域甜菜长势弱，植株黄化、矮化明显，受害植株根系有明显的须根团，根上有大量的白色雌虫。采用形态学和形态测量学的方法对孢囊线虫的雌虫、孢囊和二龄幼虫进行显微观察和测量，结果表明，在我国新疆新源县甜菜上发现的孢囊群体的2龄幼虫、孢囊及阴门锥的特征和关键形态测量值与国外已报道的甜菜孢囊线虫基本一致。采用分子生物学的方法对孢囊线虫新疆新源群体的核糖体DNA-ITS、28S-D2/D3和线粒体DNA COI基因进行克隆、测序和分析发现，新源群体的核糖体DNA-ITS, 28S-D2/D3 和线粒体DNA COI基因序列和国外已报道的甜菜孢囊线虫的一致性为99.81-100%，进化分析显示新疆新源群体与国外甜菜孢囊线虫群体聚类为一个进化分支，同时采用甜菜孢囊线虫特异性引物SHF6和rDNA2，从新疆新源群体中扩增出长度为255 bp的特异性条带，分子生物学检测结果表明：我国新疆甜菜上发现的孢囊线虫为甜菜孢囊线虫。采用柯赫氏法则，将500头二龄幼虫分别接种到甜菜（SD21816）和油菜（德油6号）根系中，15天后在甜菜和油菜根系上分别发现了137和157个孢囊和雌虫，表明新疆新源群体能够在甜菜和油菜上完成生活史，且形态学和分子生物学鉴定结果和田间样品完全一致。综上所述，经形态学鉴定和分子特征分析确认，在我国新疆新源县甜菜上发现的孢囊线虫为我国检疫性有害生物——甜菜孢囊线虫，这也是甜菜孢囊线虫在我国的首次明确报道。

大豆孢囊线虫是世界范围内大豆生产的重要病原之一，生物防治目前已成为大豆孢囊线虫病防治的重要手段。黑曲霉NBC001由本实验室从小麦孢囊线虫群体上分离获得，其发酵液拌种在盆栽中不仅可以有效防治大豆孢囊线虫，而且对大豆具有一定的促生作用。本研究将在田间评价NBC001对大豆孢囊线虫的防治效果及对大豆根际土壤产生的微生态效应。研究结果表明在田间应用黑曲霉NBC001发酵浓缩液拌种可以有效防治大豆孢囊线虫病，防效达31.7%。高通量测序结果显示黑曲霉NBC001对大豆根际土壤微生物多样性和群落结构无显著影响，表明NBC001发酵浓缩液拌种对土壤生态环境安全。在大豆定植10天时，黑曲霉 NBC001促进了大豆根际土壤中放线菌门Actinobacteria，酸杆菌门Acidobacteria，叶瘤菌属Phyllobacterium，雷尔氏菌属Ralstonia和H16的丰度；而降低拟杆菌门Bacteroidetes，芽单胞菌门Gemmatimonadetes，Adhaeribacter，芽单胞菌属Gemmatimonas，鞘氨醇单胞菌属Sphingomonas，Flavisolibacter的丰度。在定植90 d时，影响程度减小，仅增加气微菌属Aeromicrobium和RB41属的丰度，降低H16的丰度，说明其对大豆根际土壤微生物物种丰度的影响是短暂的。同时结果也表明黑曲霉NBC001可以增加大豆根际土壤中有益微生物放线菌门、酸杆菌门、气微菌属和叶瘤菌属的丰度。综上所述生防菌黑曲霉NBC001对大豆根际土壤微生物无显著影响，因此在田间应用黑曲霉NBC001对土壤生态环境安全。研究结果将为黑曲霉NBC001的安全应用奠定理论基础，为大豆孢囊线虫病生物防治提供高效生防菌株。

马铃薯孢囊线虫Globodera rostochiensis是国际公认的重要检疫性有害线虫，严重危害马铃薯。2018-2020年，在全国农业技术推广服务中心组织的全国马铃薯检疫性线虫调查中，从云南省昭通市鲁甸县和四川省越西县和昭觉县马铃薯根系发现金色孢囊线虫，经形态学观察鉴定、分子生物学rDNA-ITS及28S的D2-D3区域特征分析比对及种特异性引物ITS5和PITSr3检测确定为马铃薯金线虫Globodera rostochiensis（Wollenweber）Skarbilovich, 1959. 在隔离温室内采用盆栽人工接种的致病性研究结果表明，该三个金线虫种群都能侵染马铃薯（品种青薯9号）并繁殖，接种12周后，马铃薯上形成成熟雌虫，完成生活史。这是马铃薯金线虫在我国云南和四川省首次记录。

本研究通过室内试管石英砂培养的方法，测试香蕉穿孔线虫对本氏烟草的侵染致病过程和规律，明确了香蕉穿孔线虫侵染本氏烟草根系主要在根系皮层寄生，导致皮层细胞分解、组织腐烂。通过采用不同致病型和不同寄主来源的香蕉穿孔线虫群体对本氏烟草侵染致病的接种条件进行测定，以及对发病植株的症状表现、受害严重度和线虫繁殖率等致病性相关因子的评估，确定了香蕉穿孔线虫与本氏烟草互作研究的最佳测试条件和结果评估标准，从而建立了本氏烟草作为寄主的香蕉穿孔线虫致病性测定方法：（1）在玻璃培养试管中装入约占高度1/3 干燥的石英砂并灭菌两次；（2）将20天苗龄的本氏烟草幼苗移栽到试管中，在25±1℃条件下培养定植10 天；（3）以150条/株的接种虫量将香蕉穿孔线虫的雌虫接种到烟草根际；（4）在接种线虫30天后检测植株发病严重度、生长量和线虫繁殖量。本研究还采用该方法对致病型和寄主来源不同的8个香蕉穿孔线虫种群的致病性强弱进行了测定，证明了该方法的可行性。本研究结果为将本氏烟草作为香蕉穿孔线虫与植物互作研究的模式植物提供了依据和方法，为香蕉穿孔线虫致病性及其与寄主互作分子机制研究提供了新途径，对利用本氏烟草作为模式寄主研究香蕉穿孔线虫的致病机制和防治方法具有重要意义。

Stunt nematodes (Tylenchorhynchus spp.) are obligate migratory root ecto-parasitic nematodes found in the fields of many cultivated crops.  These nematodes, with phyto-sanitary potential, are frequently ignored or misdiagnosed as pests, and this may pose a threat to food security.  The accuracy of its identification based on a morphological approach has been challenged recently, due to the overlapping of the morphological and morphometric characters of the species.  Consequently, the objective of this study is to identify and characterize stunt nematodes present in 54 fields cultivated with cereal crops (wheat, maize and rice) in the savannahs of northern Nigeria, using integrative taxonomy and molecular approaches.  The molecular and morphological studies identified and confirmed the presence of T. annulatus as the occurring specie in the savannahs of northern Nigeria.  The phylogenetic analysis was carried out using the internal transcribed spacer (ITS) and 28S genes of ribosomal DNA further confirmed the presence of T. annulatus.  The first molecular characterization and sequences of the ITS and 28S rDNA gene for T. annulatus from Nigeria were provided by this research.  Also, according to our literature search, this is the first report on T. annulatus in wheat, maize and rice in the savannahs of northern Nigeria.  Further study to test the pathogenicity of the parasitic nematode species found in this survey is recommended for the prioritization and development of efficient management strategies.

葡萄根结线虫（Meloidogyne vitis）是在云南省葡萄根部发现的一种新的根结线虫种类，该线虫在侵染地高密度存在，已对葡萄造成严重损害。葡萄根结线虫病的发生可能对我国葡萄产业发展构成威胁，为了建立一种快速、可靠的葡萄根结线虫特异性分子检测方法，本研究以葡萄根结线虫核糖体DNA内转录间隔区(ribosomal DNA-internal transcribed spacer，rDNA-ITS)基因片段为靶标，设计筛选葡萄根结线虫种特异性检测引物，通过优化反应体系，并对所设计引物的可靠性、特异性及灵敏性进行检测验证，建立了葡萄根结线虫PCR快速分子检测技术体系。结果表明，优化后的引物最佳退火温度为53℃，该引物能够对不同龄期葡萄根结线虫进行检测；特异性检测结果表明，本研究建立的PCR分子检测技术能够从葡萄根结线虫中扩增获得长度为174 bp的特异性片段，选用的5种非靶标根结线虫则无任何扩增条带，从而将葡萄根结线虫和其他5种非靶标根结线虫有效区分开；灵敏度检测结果表明，该PCR分子检测技术能够有效的检测单头2龄幼虫和10^-4头雌虫的DNA；此外，该PCR分子检测技术能够从混合线虫种群中特异性地检测出葡萄根结线虫，并能够有效检测出土壤中的葡萄根结线虫，检测灵敏度为0.5 g土壤中可检测出2头2龄幼虫或一头雄虫。本研究建立的快速、灵敏、特异的PCR分子检测技术可用于葡萄根结线虫单头2龄幼虫的直接鉴定、混合线虫群体中葡萄根结线虫的检测及0.5 g土壤中2头2龄幼虫或一头雄虫的直接检测。本研究建立的PCR分子检测技术能够准确、快速地检测出葡萄根结线虫，将为葡萄根结线虫的发生危害调查和高效绿色防控策略的制定提供技术支撑。

水稻干尖线虫可侵染水稻、大豆、棉花等多种作物，给农业生产造成严重损失。丝氨酸羧肽酶（SerineCarboxypeptidases，SCP）是植物寄生线虫致病的一个关键因子，但丝氨酸羧肽酶在水稻干尖线虫中的致病机制并不清楚。本研究以水稻干尖线虫为对象，利用原位杂交、qRT-PCR、瞬时表达、真核表达以及基因沉默等方法对水稻干尖线虫丝氨酸羧肽酶（AbSCP1）的功能进行研究。研究得出，AbSCP1基因全长1425 bp，编码氨基酸长度为474aa。AbSCP1编码蛋白具有信号肽、无跨膜结构域，与香蕉穿孔线虫SCP蛋白的序列相似性为67%。不同龄期水稻干尖线虫AbSCP1的qPCR分析得出，该基因在幼虫中的表达量最高，其次是雌虫、雄虫和卵。通过原位杂交证实，AbSCP1在水稻干尖线虫的食道腺中表达。使用昆虫细胞表达系统获得了AbSCP1蛋白，通过与特异性底物反应证实了该蛋白的羧肽酶活性，并得出了酶促反应最适的pH为4.5。使用烟草瞬时表达系统表达AbSCP1，在烟草细胞核中出现强烈的特异荧光信号，说明AbSCP1被定位在植物细胞核中。使用RNAi研究AbSCP1对水稻干尖线虫致病力、繁殖力的影响。结果得出，水稻干尖线虫取食AbSCP1特异的dsRNA 24 h后，AbSCP1的表达量显著下降。使用基因沉默后的线虫分别接种水稻和灰葡萄孢，分别统计水稻的发病等级和线虫数。结果表明，AbSCP1被沉默后，水稻干尖线虫的致病力、繁殖率均显著下降。本研究首次在水稻干尖线虫中明确了SCP是一类可被分泌到寄主细胞核中发挥作用的蛋白酶类效应子，在线虫寄生寄主过程中起到重要作用。本研究的成果将为以AbSCP1为靶标开发高效、安全的水稻干尖线虫防治措施奠定基础。

大豆孢囊线虫（SCN, Heterodera glycines）严重制约大豆生产。大豆抗线虫数量性状遗传位点Rhg4上的丝氨酸羟甲基转移酶编码基因（GmSHMT08）对大豆孢囊线虫有显著的抗性，但该基因如何介导了对大豆孢囊线虫的抗性机制仍不明晰，GmSHMT08能否与大豆孢囊线虫产生的蛋白发生互作仍不明确。本研究以GmSHMT08作为诱饵，通过酵母双杂交体系在线虫中筛选出了与GmSHMT08互作的一个热休克蛋白70片段（HgHSP70p）。通过GST pull-down和荧光双分子互补，进一步验证了HgHSP70p与GmSHMT08之间存在互作关系。本研究发现的HgHSP70基因可以作为关键候选基因，用于进一步探究GmSHMT08介导的对大豆孢囊线虫的抗性机制。

禾谷孢囊线虫H. avenae是一种重要的植物病原线虫，严重影响禾谷类作物的产量。目前已在我国河南、河北、江苏、青海、西藏等16个省(市)发生危害。本研究通过人工接种试验和田间试验，利用抽穗期根系中的线虫数量指标评价了青海栽培二棱大麦 (QH2R)、青海栽培六棱大麦 (QH6R) 和西藏栽培二棱大麦 (TB2R) 对禾谷孢囊线虫的抗病性，并通过接种试验和显微观察，评价了两个高抗品种中线虫的侵染和发育情况。为更好地评价不同品种对H. avenae的抗感性，首先比较了两种常用的抗性评价方法——繁育系数法 (PPR) 和单株雌虫/孢囊数量法 (NFP) 的准确性。对田间自然条件下186个品种受害情况的调查结果表明，利用NFP法鉴定出的感病品种数量显著高于PPR法鉴定的感病品种数量，表明NFP法更利于鉴定大麦品种的抗病性。通过2015年至2017年的田间试验及2018年的人工接种试验，发现QH2R系列品种中形成的雌虫/孢囊数量最少，显著低于QH6R和TB2R系列品种。综合接种试验与田间试验的结果，从QH2R系列品种中鉴定出8个高抗品种 (Sunong7617, Sunong7635, Dongyuan87-14, Rudong14-46, Rudong87-57, Rudong87-8-45, Rudong88-14-2, Rudong88-67-1)，平均单株孢囊数量低于4.2个。对线虫发育进程的显微观察表明，高抗品种 (Sunong7635和Dongyuan87-14) 中H. avenae幼虫的侵入数量显著低于感病品种中幼虫的侵入数量，并且幼虫发育成雌虫的数量也显著减少。本研究中鉴定的高抗品种对于育种工作者培育禾谷孢囊线虫抗性品种、更加经济有效地控制禾谷孢囊线虫的危害等具有重要意义。

钾（K）是一种重要的营养元素，可以提高作物的抗逆性/耐受性。K在抗植物寄生线虫中的应用表明，K处理可以减少线虫病的发生，提高作物产量。然而，K在水稻抗拟禾谷根结线虫（Meloidogyne graminicola）中的研究仍然缺乏。本研究首先用K₂SO₄直接处理线虫，发现K₂SO₄对线虫的死亡率、侵染率以及发育水平无显著影响；接着通过温室盆栽接种，发现0.5 mM K₂SO₄处理水稻后，根中的根结和线虫数量分别下降了57.2±4.4% 和59.2±6.6%，成年雌虫比例（70.9±5.6%）显著低于对照（90.7±5.1%），同时幼虫比例（27.0±6.3%）显著高于对照（6.0±3.2%），而水稻的生长不受影响；统计Pluronic明胶中水稻根尖吸引的线虫数量，发现接种后6小时K₂SO₄处理与清水处理之间并无显著差异；对接种后7天根结中巨细胞的形态、大小和数量进行显微观察，发现两个处理间也不存在显著差异；接着检测根结中胼胝质沉积，发现K₂SO₄处理后其沉积面积增加了67.9%，同时其合成基因OsGSL1和降解基因OsGNS5分别显著上调和下调；另外检测H₂O₂累积发现，接种后8和24 小时K₂SO₄处理的根中H₂O₂含量分别增加了78.2% 和118.7%，同时其合成基因OsRbohB也显著上调；再对水杨酸、茉莉酸、乙烯以及油菜素内酯等信号通路相关基因和病程相关蛋白基因的表达进行定量分析，发现在线虫侵染初期K₂SO₄处理显著上调了某些抗病相关基因的表达；最后对K通道基因OsAKT1和转运蛋白基因OsHAK5缺陷型植株进行接种，发现根结和线虫数量显著增加并且线虫的发育加快，同时K₂SO₄的作用降低。这些说明K₂SO₄通过激发基础防御反应提高了水稻对线虫的抗性，并且K通道和转运蛋白积极参与了寄主抗性。K及其通道和转运蛋白在寄主抗性中的应用，为进一步研究水稻抗线虫机制以及钾在植物抗生物胁迫中的功能奠定了基础。低钾能诱导水稻对拟禾谷根结线虫的抗性，为田间有效利用钾肥防控线虫病害提供了理论依据。