Crops produced using the practice of continuous cropping can become seriously damaged by plant-parasitic nematodes,an important indicator of continuous cropping obstacles.As a typical and important perennial economic ...Crops produced using the practice of continuous cropping can become seriously damaged by plant-parasitic nematodes,an important indicator of continuous cropping obstacles.As a typical and important perennial economic crop,dragon fruit is prone to serious plant-parasitic nematode infestation;however,whether it encounters continuous cropping obstacles remains unclear.Here,we studied plant-parasitic nematodes(Meloidogyne spp.and Tylenchorhynchus sp.)in the soil and roots,soil nematode communities,metabolic footprint,soil integrated fertility,and the yield of intensively planted dragon fruit under non-continuous cropping(Y1)and 3 years(Y3)and 5 years(Y5)of continuous cropping,to determine potential continuous-cropping obstacles and factors that affect the yield of this fruit.The largest numbers of plant-parasitic nematodes in the soil and roots were observed in Y5;the associated yield was reduced,and the dragon fruit was severely stressed.Further analysis of the composition,diversity,and ecological function indices of soil nematodes showed that the soil ecological environment deteriorated after 3 years of continuous cropping,with Y5 having the worst results.Similarly,the soil at Y5 had a significant inhibitory effect on the growth and reproduction of Caenorhabditis elegans.Mantel test analysis and a random forest model showed that soil available phosphorus,soil exchange calcium,and soil nematode abundance and diversity were related significantly to yield.Partial least squares path modeling revealed that soil fertility and soil nematode diversity directly impacts the yield of continuously cropped dragon fruit.In summary,continuous cropping obstacles occurred in Y5 of intensive dragon fruit cultivation,with soil nematode diversity and soil fertility determining the crop's yield.展开更多
Entomopathogenic nematodes(EPNs)represent a promising biological control strategy for managing insect pest populations,offering an environmentally sustainable alternative to conventional chemical pesticides.This revie...Entomopathogenic nematodes(EPNs)represent a promising biological control strategy for managing insect pest populations,offering an environmentally sustainable alternative to conventional chemical pesticides.This review examines the application of EPNs in forestry,highlighting their biological and ecological characteristics,mechanisms of action,and efficacy against key forest pests.By exploring various methods of EPN application,including soil injection,foliar spray,and trunk injection,practical challenges and potential solutions for effective implementation are assessed.Case studies demonstrate successful use of EPNs in controlling pests such as bark beetles,wood borers,and root weevils,underscoring their potential for integration into integrated pest management(IPM)programs.Despite current limitations,including environmental sensitivity and application constraints,ongoing research and technological advancements continue to enhance the efficacy and reliability of EPNs.This review underscores the importance of EPNs in sustainable forestry practices and calls for further research to optimize their use and to address existing challenges,ultimately contributing to healthier forest ecosystems and reduced reliance on chemical pesticides.展开更多
Root-knot nematodes(RKNs)are the most widespread soil-borne obligate endoparasites.They can infect the roots of many crops and cause significant yield losses.The only commercially available RKN-resistant gene in tomat...Root-knot nematodes(RKNs)are the most widespread soil-borne obligate endoparasites.They can infect the roots of many crops and cause significant yield losses.The only commercially available RKN-resistant gene in tomatoes,Mi-1.2,fails at soil temperatures above 28℃.We cloned the heat-stable RKN-resistant gene,Mi-9,from a gene cluster composed of seven nucleotide-binding sites and leucine-rich repeat(NBS-LRR)type resistant genes in Solanum arcunum accession LA2157.Screening nematode infections in individual and combinatorial knockouts of five NBS-LRR genes showed that Mi-9 Candidate 4(MiC-4)alone is sufficient to confer heat-stable RKN resistance.Our study identifies a new source of heat-stable resistance to RKN in tomatoes for challenging environmental conditions.We also showcase a roadmap for rapid characterization of resistance genes by combining comparative genomics and genome editing,with the potential to be utilized in other crops.展开更多
Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-ter...Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.展开更多
A wide survey was conducted to study plant-parasitic nematodes(PPNs)associated with Prunus groves in Spain.This research aimed to determine the prevalence and distribution of PPNs in Prunus groves,as well as the influ...A wide survey was conducted to study plant-parasitic nematodes(PPNs)associated with Prunus groves in Spain.This research aimed to determine the prevalence and distribution of PPNs in Prunus groves,as well as the influence of explanatory variables describing soil,climate and agricultural management in structuring the variation of PPNs community composition.A total of 218 sampling sites were surveyed and 84 PPN species belonging to 32 genera were identified based of an integrative taxonomic approach.PPN species considered as potential limiting factors in Prunus production,such as Meloidogyne arenaria,M.incognita,M.javanica,Pratylenchus penetrans and P.vulnus,were identified in this survey.Seven soil physico-chemical(C,Mg,N,Na,OM,P,pH and clay,loamy sand and sandy loam texture classes),four climate(Bio04,Bio05,Bio13 and Bio14)and four agricultural management variables(grove-use history less than 10 years,irrigation,apricot seedling rootstock,and Montclar rootstock)were identified as the most influential variables driving spatial patterns of PPNs communities.In particular,younger plantations showed higher values for species richness and diversity indices than groves cultivated for more than 20 years with Prunus spp.Our study increases the knowledge of the distribution and prevalence of PPNs associated with Prunus rhizosphere,as well as on the influence of explanatory variables driving the spatial structure PPNs communities,which has important implications for the successful design of sustainable management strategies in the future in this agricultural system.展开更多
The latest study published in Nature by Andrew R.Burns,Peter J.Roy and co-authors is highlighted in this paper,they investigated a series of novel nematicidal compounds,including Selectivin-A and Selectivin-E,and expl...The latest study published in Nature by Andrew R.Burns,Peter J.Roy and co-authors is highlighted in this paper,they investigated a series of novel nematicidal compounds,including Selectivin-A and Selectivin-E,and explored their mechanism of action.Experiments have displayed that the Selectivin compound is inactive to human cells,fish,fungi,insects and even beneficial nematodes.In the exploration of its mechanism of action,it was found that the mechanism of action of Selectivin is different with those of commercial nematocides:Selectivin needs to be activated by biotin produced by nematodes,after that they can be transformed into compounds with high nematicidal activity.This proves that the family of Selectivin compounds has the advantages of high selectivity and environmental friendliness,and their mechanism of action is completely new,proposing a completely new path for the development of new nematicides.展开更多
This paper summarized the history and present condition of studying and utilizing entomopathogenic nematodes at home and abroad, expounded its taxonomy, life cycle and the mechanism with symbiotic bacteria killing hos...This paper summarized the history and present condition of studying and utilizing entomopathogenic nematodes at home and abroad, expounded its taxonomy, life cycle and the mechanism with symbiotic bacteria killing host insect. Taxonomy, mycelial form, pathogenic function and anti-bacteria function of symbiotic bacteria were introduced. Production and utilization of entomopathogenic nematodes, the characteristic genetic improvement by use of biological engineering technology, as well as the existing problem and applying foreground were also discussed.展开更多
The vertical distribution of the dominant genera of plant nematodes at the depth of 0–150 cm of an aquic brown soil were studied for four land use patterns, i.e., paddy field, maize field, fallow field and woodland i...The vertical distribution of the dominant genera of plant nematodes at the depth of 0–150 cm of an aquic brown soil were studied for four land use patterns, i.e., paddy field, maize field, fallow field and woodland in the Shenyang Experimental Station of Ecology, Chi- nese Academy of Sciences in November of 2003. The results showed that the numbers of some dominant genera under different land uses decreased with the increase of soil depth. Helicotylenchus was most dominant genus under each land use type. Genera of Filenchus, Psilen- chus and Tylenchus in paddy field occurred at the depth of 0–20 cm; while Paratylenchus in fallow field and woodland, as well as Praty- lenchus in maize field presented in the deeper soil layers (0–80 cm). Significant correlations between the numbers of dominant genera of plant nematodes and soil chemical properties were found in this study. The number of Helicotylenchus under different land uses was posi- tively correlated with C/N ratio, total C, total N, total P, alkai-N, and Olsen-P. The numbers of Filenchus and Paratylenchus in paddy field, Pratylenchus in maize field and Paratylenchus in fallow field were negatively correlated with soil pH, and positively correlated with total C, total N and alkai-N. This study results showed that it is essential to sample at a certain depth according to the vertical distribution informa- tion of different genera of plant nematodes in adequately assessing the population size of plant nematodes.展开更多
A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes...A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.展开更多
Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli- Udic Argosol （Cambisol, FAO） in Liaoning Province of Northeast China. A completely random design...Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli- Udic Argosol （Cambisol, FAO） in Liaoning Province of Northeast China. A completely random design with four treatments, i.e., conventional urea （CU）, slow-release urea amended with a liquid urease inhibitor （SRU1）, SRU1 ＋nitrification inhibitor dicyandiamide （SRU2）, and SRU1 ＋ nitrification inhibitor 3,5-dimethylpyrazole （SRU3） and four replicates were applied. Thirty-nine genera of nematodes were identified, with Cephalobus and Aphelenchus being dominant; and in all treatments, the dominant trophic group was bacterivores. In addition, during the growth period of spring wheat （Triticum aestivum L.）, soil urease activity was lower in SRUs than in CU. The numbers of total nematodes and bacterivores at wheat heading and ripening stages, and omnivores-predators at ripening stage were higher in SUR3 than in CU, SRU1 and SRU2 （P 〈 0.05）.展开更多
Five species of free-living marine nematodes are redescribed and illustrated as new records in the Yellow Sea of China. These species include one monhysterid, Campylaimus gerlachi in the family Diplopeltidae and four ...Five species of free-living marine nematodes are redescribed and illustrated as new records in the Yellow Sea of China. These species include one monhysterid, Campylaimus gerlachi in the family Diplopeltidae and four enoplids species, Oxystomina elongata, Oxystomina elegans, Halalaimus lutarus and Halalaimus wodjanizkii in the family Oxystominidae. Ecological and taxonomic remarks are provided and discussed in comparison with the original description. The key to all known species of the genus Campylaimus is given. Our findings have offerred the taxonomic information of nematodes to the benthic ecology and biodiversity studies of the Yellow Sea.展开更多
Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gube...Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gubernaculum median piece. The characters of S. breviseta agree quite well with the European original descriptions and only differ in the male amphid turns (5.5 vs. 4.0 turns) and unmodified preanal supplements (5-7 vs. 6). S. pulchra can be recognized by amphid 2.75 turns, irregularly arranged lateral dots, and the first three supplements anterior to the anus, which are more widely spaced than the following ones. The excretory system of S. breviseta and S. pulchra shows sexual dimorphism. S. celtica is defined by amphids 2.00-2.25 turns, weakly developed pharyngeal bulb, curved apophyses and 12-13 conspicuous supplements. C. deltensis is characterized by amphids 4.75 turns, ovate pharyngeal posterior bulb, sperm dimorphism, 7 thin preanal supplements, and long tail cylindrical portion (50%-53% of tail length). All the three Sabatieria species are for the first time recorded in Chinese waters. C. deltensis was originally isolated from the Bohai Sea and Yellow Sea and newly recorded in the East China Sea.展开更多
A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples ...A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples collected at five stations in the deep sea （from 313 to 1 600 m） and one station in shallowwaters （87 m） during the cruise in September, 2010. Results showed that the abundance of marine nematodes ranged from 224 to 1 996 ind./（10 cm2）. A total of 69 free-living marine nematode genera, belonging to 26 families and three orders, were identified. The most dominant genera were Sabatieria, Linhystera, Aegialoalaimus and Daptonema according to SIMPER analysis. Results of CLUSTER analysis revealed four types of marine nematode community （or station groups） in the sampling area. In terms of trophic structure, non-selective deposit feeders （1B） and selective deposit feeders （1A） were the dominant trophic types with highest genera numbers and abundances, which implied that organic detritus was the main food source of marine nematodes in the northern South China Sea. The percentage of male nematode was low, ranging from 2.22% to 17.81%, while those of juvenile individuals ranged from 36.99% to 82.09%. For genera level diversity of marine nematodes, Shannon-Wiener diversity indices （H＇） ranged from 3.76 to 4.57 and had highly significant negative correlation with water depth. In general, diversity indices H＇ at the five stations in deep sea （over 200 m） were lower than that at the station in shallow waters （87 m）. BIOENV analysis showed that the most important environmental factor controlling marine nematode communities was water denth.展开更多
Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove...Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.展开更多
Six species of new records collected from intertidal mangrove/non-mangrove and subtidal cave sediments during a mangrove ecological study (1998-2001) and a marine cave expedition (2002) in Hong Kong waters are redescr...Six species of new records collected from intertidal mangrove/non-mangrove and subtidal cave sediments during a mangrove ecological study (1998-2001) and a marine cave expedition (2002) in Hong Kong waters are redescribed. These include two enoplids: Anoplostoma viviparum in Anoplostomatidae and Trissonchulus janetae in Ironidae, two chromadorids:Paracomesoma dubium and Actarjania splendens in Comesomatidae, and two monhysterids: Parodontophora marina and Parodontophora c.f. danker in Axonolaimidae. Five of them are the first records from China. Ecological and taxonomic remarks are provided and discussed in comparison with the original descriptions.展开更多
Two new species of free living nematodes Tripyloides mangrovensis n. sp. and Tripyloides amoyanus n. sp. of genus Tripyloides de Man, 1886 are described from mangroves of the Tong＇an Bay and Haimen Island in the Xiam...Two new species of free living nematodes Tripyloides mangrovensis n. sp. and Tripyloides amoyanus n. sp. of genus Tripyloides de Man, 1886 are described from mangroves of the Tong＇an Bay and Haimen Island in the Xiamen Bay, China. The two species are both characterized by six stout outer labial setae, male without preanal papillae, tail conico-cylindrical without swollen terminally. Tripyloides mangrovensis n. sp. can be additionally by its buccal cavity consisting of two parts, amphid circular, distinct proximal conical and distal slender cylindrical portions, 2/3 of the tail cylindrical. Tripyloides amoyanus n. sp. is distinguished by buccal cavity consisting of three parts with small tooth, amphid small, rounded, like a comma-shaped loop, 1/3 of the tail cylindrical, gubernaculum with four denticles.展开更多
Objective: To explore anthelmintic effects of oral administration of aqueous extract of Sauce llorón(Salix babylonica; SB) against gastrointestinal nematodes and Moniezia spp. Methods: Sixteen Pelibuey male lambs...Objective: To explore anthelmintic effects of oral administration of aqueous extract of Sauce llorón(Salix babylonica; SB) against gastrointestinal nematodes and Moniezia spp. Methods: Sixteen Pelibuey male lambs of 3-4 months of age and(23.7±3.3) kg body weight were used in a completely randomized design to be fed a total mixed ration(Control; SB0), or Control plus SB extract using 20(SB20), 40(SB40) and 60(SB60) mL/lamb/day for 45 days. Lambs had a natural gastrointestinal nematodes and Moniezia spp. infection and had never been treated with chemical anthelmintic drugs. Individual faecal samples were collected for ova counting using Mc Master procedure after 0, 7, 14, 21, 30 and 45 days post extract administration. Results: No extract dose×day interactions for both gastrointestinal nematodes and Monieziaspp. egg count were found. Administration of SB extract had a higher effect(quadratic effect, P=0.0064) at dose of 20 mL SB/lamb/day for gastrointestinal nematode eggs during the first 21 days; however, the dose of SB40 tended(linear effect, P=0.0897) to be more effective than the others for Moniezia spp. egg during the first 7 days. Sampling day had a linear(P=0.0436) effect on Moniezia spp. egg count. Conclusions: The aqueous extract of SB could be more effective against nematodes at 20 and at 40 mL/lamb/day for Moniezia spp. The use of the SB extract could represent a promising alternative to synthetic anthelmintics for the treatment of gastrointestinal nematodes and Moniezia spp. in small ruminants from organic and conventional production systems.展开更多
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 misdiagno...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.展开更多
Functional structure and diversity of soil free-living nematodes in a desert environment depend on plant gender and sampling site.The objective of this study was to compare the composition,abundance and tropic group o...Functional structure and diversity of soil free-living nematodes in a desert environment depend on plant gender and sampling site.The objective of this study was to compare the composition,abundance and tropic group of soil free-living nematodes in the upper 0–10 cm soil layer under the male and female Acanthosicyos horridus Welw.ex Hook.f.plants and in the inter-shrub open areas(control)in the Namib Desert,Namibia in April 2015.Soil moisture,organic matter(OM)and pH was also analyzed.Free-living nematodes were extracted from 100 g soil using the Baermann funnel procedure,and total number of nematodes was counted under a microscope.Community composition and diversity of soil free-living nematodes were analyzed using 18S rDNA sequences.Results indicated that a total of 67 groups,including 64 species,2 genera and 1 family were identified.Feeding behavior of 58 species were identified as follows:15 bacteria-feeding species,12 fungi-feeding species,10 plant-parasite species,5 omnivorous-predator species,8 animal-parasite species,5 invertebrate-parasite species and 3 non-free-living nematodes,known as marine species.Moreover,soil free-living nematodes were found to be affected by sampling locations and plant gender,and community composition and density of these nematodes were strongly influenced by soil OM content.Result confirmed that spatial location and plant cover were main factors influencing the diversity of soil free-living nematodes.Moreover,molecular tools were found to be very useful in defining the richness of soil non-free-living nematodes.In conclusion,the results elucidated the importance of biotic variables in determining the composition and abundance of soil free-living nematodes in the Namib Desert,Namibia.展开更多
Soybean cyst nematode(SCN), Heterodera glycine, is one of the important diseases affecting the yield of soybean(Glycine max) worldwide. Host-plant resistance is the most economically effective way to control SCN. Iden...Soybean cyst nematode(SCN), Heterodera glycine, is one of the important diseases affecting the yield of soybean(Glycine max) worldwide. Host-plant resistance is the most economically effective way to control SCN. Identification of DNA markers linked to SCN resistance genes is one of the important steps in the marker-assisted selection(MAS) for nematode resistance breeding. Quantitative trait loci(QTLs) controlled by mul-tiple resistance genes plays a powerful role in MAS-breeding program. In this paper, we reviewed genetic resistance of SCN, molecular markers of resistance gene and Genome-Wide Associated Study(GWAS) of QTLs linked to SCN resistance, explored the present problems of genetic resistance,and prospected the future of QTL analysis.展开更多
基金supported by the National Key Research and Development Program of China(2023YFD1700203and 2022YFD1901501)the Tianchi Talent Introduction Program of Xinjiang Autonomous Region,China(2023-“2+5”)the Tingzhou Talent Introduction Program of Changji Autonomous Region,China(2023)。
文摘Crops produced using the practice of continuous cropping can become seriously damaged by plant-parasitic nematodes,an important indicator of continuous cropping obstacles.As a typical and important perennial economic crop,dragon fruit is prone to serious plant-parasitic nematode infestation;however,whether it encounters continuous cropping obstacles remains unclear.Here,we studied plant-parasitic nematodes(Meloidogyne spp.and Tylenchorhynchus sp.)in the soil and roots,soil nematode communities,metabolic footprint,soil integrated fertility,and the yield of intensively planted dragon fruit under non-continuous cropping(Y1)and 3 years(Y3)and 5 years(Y5)of continuous cropping,to determine potential continuous-cropping obstacles and factors that affect the yield of this fruit.The largest numbers of plant-parasitic nematodes in the soil and roots were observed in Y5;the associated yield was reduced,and the dragon fruit was severely stressed.Further analysis of the composition,diversity,and ecological function indices of soil nematodes showed that the soil ecological environment deteriorated after 3 years of continuous cropping,with Y5 having the worst results.Similarly,the soil at Y5 had a significant inhibitory effect on the growth and reproduction of Caenorhabditis elegans.Mantel test analysis and a random forest model showed that soil available phosphorus,soil exchange calcium,and soil nematode abundance and diversity were related significantly to yield.Partial least squares path modeling revealed that soil fertility and soil nematode diversity directly impacts the yield of continuously cropped dragon fruit.In summary,continuous cropping obstacles occurred in Y5 of intensive dragon fruit cultivation,with soil nematode diversity and soil fertility determining the crop's yield.
文摘Entomopathogenic nematodes(EPNs)represent a promising biological control strategy for managing insect pest populations,offering an environmentally sustainable alternative to conventional chemical pesticides.This review examines the application of EPNs in forestry,highlighting their biological and ecological characteristics,mechanisms of action,and efficacy against key forest pests.By exploring various methods of EPN application,including soil injection,foliar spray,and trunk injection,practical challenges and potential solutions for effective implementation are assessed.Case studies demonstrate successful use of EPNs in controlling pests such as bark beetles,wood borers,and root weevils,underscoring their potential for integration into integrated pest management(IPM)programs.Despite current limitations,including environmental sensitivity and application constraints,ongoing research and technological advancements continue to enhance the efficacy and reliability of EPNs.This review underscores the importance of EPNs in sustainable forestry practices and calls for further research to optimize their use and to address existing challenges,ultimately contributing to healthier forest ecosystems and reduced reliance on chemical pesticides.
基金supported by the National Key R&D Program of China(2018YFA0900600 and 2021YFF1000103-5)the Strategic Priority Research Program of Chinese Academy of Sciences(XDA24030503)。
文摘Root-knot nematodes(RKNs)are the most widespread soil-borne obligate endoparasites.They can infect the roots of many crops and cause significant yield losses.The only commercially available RKN-resistant gene in tomatoes,Mi-1.2,fails at soil temperatures above 28℃.We cloned the heat-stable RKN-resistant gene,Mi-9,from a gene cluster composed of seven nucleotide-binding sites and leucine-rich repeat(NBS-LRR)type resistant genes in Solanum arcunum accession LA2157.Screening nematode infections in individual and combinatorial knockouts of five NBS-LRR genes showed that Mi-9 Candidate 4(MiC-4)alone is sufficient to confer heat-stable RKN resistance.Our study identifies a new source of heat-stable resistance to RKN in tomatoes for challenging environmental conditions.We also showcase a roadmap for rapid characterization of resistance genes by combining comparative genomics and genome editing,with the potential to be utilized in other crops.
基金supported by the National Key R&D Program of China(2023YFC2604500)the National Natural Science Foundation of China(32171662,32471753 and 32171666)the Natural Science Foundation of Liaoning(2020-MS-199).
文摘Exotic plant invasions and increased atmospheric carbon dioxide(CO_(2))concentration have been determined to independently affect soil nematodes,a key component of soil biota.However,little is known about the long-term effects of these two global change factors and their interactive effects.Over three consecutive years,we cultivated invasive alien plant Xanthium strumarium and its two phylogenetically related natives under both ambient(aCO_(2))and elevated(eCO_(2))atmospheric CO_(2)concentrations,and determined the effects of the invader and natives on soil nematodes under different CO_(2)concentrations and the relevant mechanism.The abundance of total soil nematodes and that of the dominant trophic group(herbivores)were significantly affected by plant species and CO_(2)concentration,and these effects were dependent on the experimental duration,however,the Shannon-diversity of nematodes was not affected by these factors.Under aCO_(2),both invasive and native species significantly increased the total nematode abundance and that of the dominant trophic group with increasing experimental duration,and the amplitude of the increase was greater under the invader relative to the natives.The eCO_(2)increased total nematode abundance(second year)and that of the dominant trophic group(third year)under the invader,but not under the natives(or even decreased)with increasing experimental duration.Root litter had greater effects on soil nematode abundance than leaf litter and root exudates did.This study indicates that eCO_(2)would aggravate effects of invasive plants on soil nematodes by increasing abundance,and these effects would vary with the duration.
基金supported by the grant RTI2018-095925-A-100,“Interactions among soil microorganisms as a tool for the sustainability of the resistance of rootstocks fruit trees against plant-parasitic nematodes”funded by Ministry of Science and Innovation(MCIN)and by European Regional Development Fund(ERDF)“A way of making Europe”The first author is a recipient of grant(PRE2019-090206)funded by European Social Fund(ESF)“Investing in your future”。
文摘A wide survey was conducted to study plant-parasitic nematodes(PPNs)associated with Prunus groves in Spain.This research aimed to determine the prevalence and distribution of PPNs in Prunus groves,as well as the influence of explanatory variables describing soil,climate and agricultural management in structuring the variation of PPNs community composition.A total of 218 sampling sites were surveyed and 84 PPN species belonging to 32 genera were identified based of an integrative taxonomic approach.PPN species considered as potential limiting factors in Prunus production,such as Meloidogyne arenaria,M.incognita,M.javanica,Pratylenchus penetrans and P.vulnus,were identified in this survey.Seven soil physico-chemical(C,Mg,N,Na,OM,P,pH and clay,loamy sand and sandy loam texture classes),four climate(Bio04,Bio05,Bio13 and Bio14)and four agricultural management variables(grove-use history less than 10 years,irrigation,apricot seedling rootstock,and Montclar rootstock)were identified as the most influential variables driving spatial patterns of PPNs communities.In particular,younger plantations showed higher values for species richness and diversity indices than groves cultivated for more than 20 years with Prunus spp.Our study increases the knowledge of the distribution and prevalence of PPNs associated with Prunus rhizosphere,as well as on the influence of explanatory variables driving the spatial structure PPNs communities,which has important implications for the successful design of sustainable management strategies in the future in this agricultural system.
基金supported in part by the National Key Research and Development Program of China(2021YFD1700103)the National Natural Science Foundation of China(22177051,32061143045)+1 种基金the Fundamental Research Funds for the Central Universities(KYCYXT2022010)Sichuan Key Research and Development Program(22ZDYF0186,2021YFN0134).
文摘The latest study published in Nature by Andrew R.Burns,Peter J.Roy and co-authors is highlighted in this paper,they investigated a series of novel nematicidal compounds,including Selectivin-A and Selectivin-E,and explored their mechanism of action.Experiments have displayed that the Selectivin compound is inactive to human cells,fish,fungi,insects and even beneficial nematodes.In the exploration of its mechanism of action,it was found that the mechanism of action of Selectivin is different with those of commercial nematocides:Selectivin needs to be activated by biotin produced by nematodes,after that they can be transformed into compounds with high nematicidal activity.This proves that the family of Selectivin compounds has the advantages of high selectivity and environmental friendliness,and their mechanism of action is completely new,proposing a completely new path for the development of new nematicides.
基金This paper was supported by Natural Science Founda-tion of Heilongjiang Province (No.C-9735).
文摘This paper summarized the history and present condition of studying and utilizing entomopathogenic nematodes at home and abroad, expounded its taxonomy, life cycle and the mechanism with symbiotic bacteria killing host insect. Taxonomy, mycelial form, pathogenic function and anti-bacteria function of symbiotic bacteria were introduced. Production and utilization of entomopathogenic nematodes, the characteristic genetic improvement by use of biological engineering technology, as well as the existing problem and applying foreground were also discussed.
文摘The vertical distribution of the dominant genera of plant nematodes at the depth of 0–150 cm of an aquic brown soil were studied for four land use patterns, i.e., paddy field, maize field, fallow field and woodland in the Shenyang Experimental Station of Ecology, Chi- nese Academy of Sciences in November of 2003. The results showed that the numbers of some dominant genera under different land uses decreased with the increase of soil depth. Helicotylenchus was most dominant genus under each land use type. Genera of Filenchus, Psilen- chus and Tylenchus in paddy field occurred at the depth of 0–20 cm; while Paratylenchus in fallow field and woodland, as well as Praty- lenchus in maize field presented in the deeper soil layers (0–80 cm). Significant correlations between the numbers of dominant genera of plant nematodes and soil chemical properties were found in this study. The number of Helicotylenchus under different land uses was posi- tively correlated with C/N ratio, total C, total N, total P, alkai-N, and Olsen-P. The numbers of Filenchus and Paratylenchus in paddy field, Pratylenchus in maize field and Paratylenchus in fallow field were negatively correlated with soil pH, and positively correlated with total C, total N and alkai-N. This study results showed that it is essential to sample at a certain depth according to the vertical distribution informa- tion of different genera of plant nematodes in adequately assessing the population size of plant nematodes.
文摘A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.
基金Project supported by the National Key Basic Research Support Foundation of China (No. 2005CB121105) and the National High Technology Research and Development Program of China (No. 2005AA001480).
文摘Effects of urea amended with urease and nitrification inhibitors on soil nematode communities were studied in a Hapli- Udic Argosol （Cambisol, FAO） in Liaoning Province of Northeast China. A completely random design with four treatments, i.e., conventional urea （CU）, slow-release urea amended with a liquid urease inhibitor （SRU1）, SRU1 ＋nitrification inhibitor dicyandiamide （SRU2）, and SRU1 ＋ nitrification inhibitor 3,5-dimethylpyrazole （SRU3） and four replicates were applied. Thirty-nine genera of nematodes were identified, with Cephalobus and Aphelenchus being dominant; and in all treatments, the dominant trophic group was bacterivores. In addition, during the growth period of spring wheat （Triticum aestivum L.）, soil urease activity was lower in SRUs than in CU. The numbers of total nematodes and bacterivores at wheat heading and ripening stages, and omnivores-predators at ripening stage were higher in SUR3 than in CU, SRU1 and SRU2 （P 〈 0.05）.
文摘Five species of free-living marine nematodes are redescribed and illustrated as new records in the Yellow Sea of China. These species include one monhysterid, Campylaimus gerlachi in the family Diplopeltidae and four enoplids species, Oxystomina elongata, Oxystomina elegans, Halalaimus lutarus and Halalaimus wodjanizkii in the family Oxystominidae. Ecological and taxonomic remarks are provided and discussed in comparison with the original description. The key to all known species of the genus Campylaimus is given. Our findings have offerred the taxonomic information of nematodes to the benthic ecology and biodiversity studies of the Yellow Sea.
文摘Three species in genus Sabatieria and one in genus Cervonema from the East China Sea were recorded. S. breviseta is characterized by uniformly punctuated coarse dots, large amphids of 5.5 turns (♂) and prominent gubernaculum median piece. The characters of S. breviseta agree quite well with the European original descriptions and only differ in the male amphid turns (5.5 vs. 4.0 turns) and unmodified preanal supplements (5-7 vs. 6). S. pulchra can be recognized by amphid 2.75 turns, irregularly arranged lateral dots, and the first three supplements anterior to the anus, which are more widely spaced than the following ones. The excretory system of S. breviseta and S. pulchra shows sexual dimorphism. S. celtica is defined by amphids 2.00-2.25 turns, weakly developed pharyngeal bulb, curved apophyses and 12-13 conspicuous supplements. C. deltensis is characterized by amphids 4.75 turns, ovate pharyngeal posterior bulb, sperm dimorphism, 7 thin preanal supplements, and long tail cylindrical portion (50%-53% of tail length). All the three Sabatieria species are for the first time recorded in Chinese waters. C. deltensis was originally isolated from the Bohai Sea and Yellow Sea and newly recorded in the East China Sea.
基金The Fundamental Research Funds for Central Universities of the Ministry of Education of China from Ocean University of China under contract Nos 201362018 and 201462008the National Natural Science Foundation of China under contract No.41006081the Scientific Research Award Foundation for Outstanding Middle-aged and Young Scientists of Shandong Province under contract No.BS2013HZ008
文摘A quantitative study on the community structure and biodiversity of free-living marine nematodes and their relationship with environmental factors in the northern South China Sea were carried out based on the samples collected at five stations in the deep sea （from 313 to 1 600 m） and one station in shallowwaters （87 m） during the cruise in September, 2010. Results showed that the abundance of marine nematodes ranged from 224 to 1 996 ind./（10 cm2）. A total of 69 free-living marine nematode genera, belonging to 26 families and three orders, were identified. The most dominant genera were Sabatieria, Linhystera, Aegialoalaimus and Daptonema according to SIMPER analysis. Results of CLUSTER analysis revealed four types of marine nematode community （or station groups） in the sampling area. In terms of trophic structure, non-selective deposit feeders （1B） and selective deposit feeders （1A） were the dominant trophic types with highest genera numbers and abundances, which implied that organic detritus was the main food source of marine nematodes in the northern South China Sea. The percentage of male nematode was low, ranging from 2.22% to 17.81%, while those of juvenile individuals ranged from 36.99% to 82.09%. For genera level diversity of marine nematodes, Shannon-Wiener diversity indices （H＇） ranged from 3.76 to 4.57 and had highly significant negative correlation with water depth. In general, diversity indices H＇ at the five stations in deep sea （over 200 m） were lower than that at the station in shallow waters （87 m）. BIOENV analysis showed that the most important environmental factor controlling marine nematode communities was water denth.
基金funded by the National Natural Science Foundation of China (No. 41606119)the Provincial Natural Science Foundation of Fujian (No. 2017J05068)the New Century Outstanding Talents Support Program for Institutions of Higher Learning in Fujian Province and Building Ecological Security for Urban Agglomeration and Integrating Ecological Restoration Techniques for Coastal Zones in Fujian River Deltas (No. 2016YFC0502900)
文摘Mangroves are unique in their biodiversity,but studies on their meiobenthic biodiversity in China are scarce.Despite the importance of mangroves,little work has been done on the classification of nematodes in mangrove wetlands.Fujian Province is the most northern point of China’s natural mangrove distribution,and it is also one of the provinces with the earliest constructed mangrove forest.In this paper,two new free-living marine nematode species of Desmodoridae from the Xiamen mangrove wetlands in China are described.Metachromadora xiamenensis sp.nov.is characterized by a cylindrical body,and smooth head capsule set off from the rest of the body.The cuticle is finely annulated and thickened at the midbody.Lateral ridges run from the posterior end of the pharynx to the middle of the tail.The amphid foveae is loop shaped and opens at the top with a double contour amphidial,pharynx with bipartite cuticularized internal cavity.There are 18 tubular precloacal supplements and tail with three small protuberances.Molgolaimus euryformis sp.nov.is characterized by a relatively short and plump body with finely annulated cuticle,which is particularly obvious in the tail.The head is small and wide with intensive striates.The inner and outer labial sensilla are indistinct with short spicules and ventral apophysis,a gubernaculum with a block-shaped hook,a swollen conical-cylindrical tail and an absence of precloacal supplements.
基金funded by National Key Basic Research Program from the Ministry of Science and Technology,People’s Repubfic of China(G 19990437)also supported by the National Natural Science Foundation of China(No.40176033)
文摘Six species of new records collected from intertidal mangrove/non-mangrove and subtidal cave sediments during a mangrove ecological study (1998-2001) and a marine cave expedition (2002) in Hong Kong waters are redescribed. These include two enoplids: Anoplostoma viviparum in Anoplostomatidae and Trissonchulus janetae in Ironidae, two chromadorids:Paracomesoma dubium and Actarjania splendens in Comesomatidae, and two monhysterids: Parodontophora marina and Parodontophora c.f. danker in Axonolaimidae. Five of them are the first records from China. Ecological and taxonomic remarks are provided and discussed in comparison with the original descriptions.
基金The National Natural Science Foundation of China under contract No.41376113the Public Science and Technology Research Funds Projects of Ocean under contract No.201505004the National Key Research and Development Program of China under contract No.2016YFC0502900
文摘Two new species of free living nematodes Tripyloides mangrovensis n. sp. and Tripyloides amoyanus n. sp. of genus Tripyloides de Man, 1886 are described from mangroves of the Tong＇an Bay and Haimen Island in the Xiamen Bay, China. The two species are both characterized by six stout outer labial setae, male without preanal papillae, tail conico-cylindrical without swollen terminally. Tripyloides mangrovensis n. sp. can be additionally by its buccal cavity consisting of two parts, amphid circular, distinct proximal conical and distal slender cylindrical portions, 2/3 of the tail cylindrical. Tripyloides amoyanus n. sp. is distinguished by buccal cavity consisting of three parts with small tooth, amphid small, rounded, like a comma-shaped loop, 1/3 of the tail cylindrical, gubernaculum with four denticles.
基金supported by la SEP,Mexico,Project PROMEP 103.5/09/4195
文摘Objective: To explore anthelmintic effects of oral administration of aqueous extract of Sauce llorón(Salix babylonica; SB) against gastrointestinal nematodes and Moniezia spp. Methods: Sixteen Pelibuey male lambs of 3-4 months of age and(23.7±3.3) kg body weight were used in a completely randomized design to be fed a total mixed ration(Control; SB0), or Control plus SB extract using 20(SB20), 40(SB40) and 60(SB60) mL/lamb/day for 45 days. Lambs had a natural gastrointestinal nematodes and Moniezia spp. infection and had never been treated with chemical anthelmintic drugs. Individual faecal samples were collected for ova counting using Mc Master procedure after 0, 7, 14, 21, 30 and 45 days post extract administration. Results: No extract dose×day interactions for both gastrointestinal nematodes and Monieziaspp. egg count were found. Administration of SB extract had a higher effect(quadratic effect, P=0.0064) at dose of 20 mL SB/lamb/day for gastrointestinal nematode eggs during the first 21 days; however, the dose of SB40 tended(linear effect, P=0.0897) to be more effective than the others for Moniezia spp. egg during the first 7 days. Sampling day had a linear(P=0.0436) effect on Moniezia spp. egg count. Conclusions: The aqueous extract of SB could be more effective against nematodes at 20 and at 40 mL/lamb/day for Moniezia spp. The use of the SB extract could represent a promising alternative to synthetic anthelmintics for the treatment of gastrointestinal nematodes and Moniezia spp. in small ruminants from organic and conventional production systems.
基金funded by the National Natural Science Foundation of China(31772142)the Research Foundation for Ph D of the Graduate School of Chinese Academy of Agricultural Sciences,China(2018Y90100033)the Special Fund for Agro-Scientific Research in the Public Interest of China(210503114)。
文摘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.
文摘Functional structure and diversity of soil free-living nematodes in a desert environment depend on plant gender and sampling site.The objective of this study was to compare the composition,abundance and tropic group of soil free-living nematodes in the upper 0–10 cm soil layer under the male and female Acanthosicyos horridus Welw.ex Hook.f.plants and in the inter-shrub open areas(control)in the Namib Desert,Namibia in April 2015.Soil moisture,organic matter(OM)and pH was also analyzed.Free-living nematodes were extracted from 100 g soil using the Baermann funnel procedure,and total number of nematodes was counted under a microscope.Community composition and diversity of soil free-living nematodes were analyzed using 18S rDNA sequences.Results indicated that a total of 67 groups,including 64 species,2 genera and 1 family were identified.Feeding behavior of 58 species were identified as follows:15 bacteria-feeding species,12 fungi-feeding species,10 plant-parasite species,5 omnivorous-predator species,8 animal-parasite species,5 invertebrate-parasite species and 3 non-free-living nematodes,known as marine species.Moreover,soil free-living nematodes were found to be affected by sampling locations and plant gender,and community composition and density of these nematodes were strongly influenced by soil OM content.Result confirmed that spatial location and plant cover were main factors influencing the diversity of soil free-living nematodes.Moreover,molecular tools were found to be very useful in defining the richness of soil non-free-living nematodes.In conclusion,the results elucidated the importance of biotic variables in determining the composition and abundance of soil free-living nematodes in the Namib Desert,Namibia.
基金Supported by General Project of National Natural Science Foundation of China(31772139,31471749)Key Project of Natural Science Foundation of Heilongjiang Province(ZD2017006)Hundred Talents Program of Chinese Academy of Sciences
文摘Soybean cyst nematode(SCN), Heterodera glycine, is one of the important diseases affecting the yield of soybean(Glycine max) worldwide. Host-plant resistance is the most economically effective way to control SCN. Identification of DNA markers linked to SCN resistance genes is one of the important steps in the marker-assisted selection(MAS) for nematode resistance breeding. Quantitative trait loci(QTLs) controlled by mul-tiple resistance genes plays a powerful role in MAS-breeding program. In this paper, we reviewed genetic resistance of SCN, molecular markers of resistance gene and Genome-Wide Associated Study(GWAS) of QTLs linked to SCN resistance, explored the present problems of genetic resistance,and prospected the future of QTL analysis.
