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
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
Soybean cyst nematode(SCN,Heterodera glycines)is a devastating pathogen that infects soybean(Glycine max L.Merrill)and disrupts soybean production worldwide.SCN infection upregulates or downregulates the expression of...Soybean cyst nematode(SCN,Heterodera glycines)is a devastating pathogen that infects soybean(Glycine max L.Merrill)and disrupts soybean production worldwide.SCN infection upregulates or downregulates the expression of multiple genes in soybean.However,the regulatory mechanisms that underlie these changes in gene expression remain largely unexplored.N^(6)-methyladenosine(m^(6)A)methylation,one of the most prevalent mRNA modifications,contributes to transcriptional reprogramming during plant responses to pathogen infection.Nevertheless,the role of m^(6)A methylation in establishing compatible and incompatible soybean responses to SCN has not previously been studied.Here,we performed transcriptome-wide m^(6)A profiling of soybean roots infected with virulent and avirulent populations of SCN.Compared with the compatible response,the incompatible response was associated with higher global m^(6)A methylation levels,as well as more differentially modified m^(6)A peaks(DMPs)and differentially expressed genes(DEGs).A total of 133 and 194 genes showed significant differences in both transcriptional expression and m^(6)A methylation levels in compatible and incompatible interactions;the most significantly enriched gene ontology terms associated with these genes were plant–pathogen interaction(compatible)and folate biosynthesis(incompatible).Our findings demonstrate that the m^(6)A methylation profiles of compatible and incompatible soybean responses are distinct and provide new insights into the regulatory mechanism underlying soybean response to SCN at the post-transcriptional modification level,which will be valuable for improving the SCN-resistant breeding.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
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
The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province...The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.展开更多
Soil nematode communities were investigated in the Changbai Mountain in Broad-leaved Korean Pine forest, Korean Pine and spruce-fix mixed forest, Dark Coniferous forest, Erman＇s birch forest and Alpine tundra along d...Soil nematode communities were investigated in the Changbai Mountain in Broad-leaved Korean Pine forest, Korean Pine and spruce-fix mixed forest, Dark Coniferous forest, Erman＇s birch forest and Alpine tundra along different altitude gradients from 762 m to 2 200 m a.s.l. Soil animal samples were collected from the litter layer and the soil depth of 0-5 cm, 5-10 cm and 10-20 cm at each site in the spring of 2001 and 2002. In total 27 nematode families and 60 genera were observed. The dominant genera were Plectus Bastian and Tylenchus Bastian and most of them live in litter layer. The total number of soil nematode was significantly correlated with soil moisture （r=0.357; p〈0.01）. Nematodes were classified in bacterivores, fungivores, plant parasites, omnivores-predators, and omnivores according to known feeding habitats or stoma and esophageal morphology. Species richness of fungivorous nematode was higher than others in different vegetation communities and soil depths. The total number of soil nematode and trophic groups varied significantly （o〈0.05） in response to different soil depths. The fungivore/bacterivore ratio （F/B） and the ratio of （fungivores ＋ bacterivores）/plant-parasites （WI） also changed significantly （p〈0.05） in different soil depths. In conclusion, soil moisture is proved to be one of the most important variables affecting nematode density and trophic composition, and the altitude gradient does not significantly affect the ecological indices of soil nematode such as trophic diversity （TD） and the Shannon index （H＇）.展开更多
Tobacco root-knot nematode disease has caused severe damage in Geng- ma County, Yunnan Province. In order to identify the pathogenic factors of the tobac- co root-knot nematode disease in this county, the pathogenic n...Tobacco root-knot nematode disease has caused severe damage in Geng- ma County, Yunnan Province. In order to identify the pathogenic factors of the tobac- co root-knot nematode disease in this county, the pathogenic nematodes, hosts and environment of tobacco fields in Mengsa, Hepai and Sipaishan 3 main tobacco-grow- ing towns in Gengma County were investigated and analyzed based on the local re- lated field survey on tobacco root-knot nematode disease in this county in 2012. The results showed the incidence and severity of the tobacco root-knot nematode disease were all higher than those of previous years. dominant pathogens of the tobacco root-knot The species identification showed the nematode disease were Meloidogyne arenaria and M. javanica in Gengma County. The lacking of disease-resistant culti- vars, poor management and climatic anomaly were the main causes of the tobacco root-knot nematode disease in Gengma. According to the occurrence characteristics of the disease, the agricultural prevention-based control measures were proposed.展开更多
[ Objective] The paper was to identify endophytic bacillus BHL3501 from wild soybean and its inhibitory effect against soybean cyst nematode. [ Meth- od] Through morphological characteristic, physiological and biochem...[ Objective] The paper was to identify endophytic bacillus BHL3501 from wild soybean and its inhibitory effect against soybean cyst nematode. [ Meth- od] Through morphological characteristic, physiological and biochemical characteristics and 16S rDNA analysis, a strain of endophytic bacterium BHL3501 with ne- maticidal activity isolated and screened from the root of wild soybean was identified, the effects of BHL3501 metabolite solutions with different dilution multiples on egg hatching and activity of 2rd instar juvenile of soybean cyst nematode were also studied. [ Result ] BHL3501 strain was preliminarily identified to be Bacillus sp.. The relative inhibitory rate of its original fermentation broth on egg hatching of soybean cyst nematode after 24 h was 98.3% ; the relative inhibitory rate under 10- time diluted solution treatment was 79.5%, which had significant difference with sterile water control. The corrected mortality rate of 24 instar juvenile was 93.1% after treated by original fermentation broth for 24 h, the treatments of all diluted solutions had significant difference with sterile water control. [ Conclusion ] BHL3501 metabolites had strong inhibitory effect against egg hatching of soybean cyst nematode, which also had strong toxic effect on its 2nd instar juvenile.展开更多
Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicid...Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.展开更多
A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode ...A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode Protorhabditis sp. stimulated the growth of wheat (Triticum aestivum) and the uptake of N. By the end of the 40-day incubation wheat biomass and N uptake in the treatment with nematode and bacteria (Pseudomonas sp.) increased by 6.5% and 5.9%, respectively, compared with bacteria alone treatment. The presence of nematode mainly accelerated the growth of aboveground of wheat, while it slightly inhibited the root development. There was little difference in plant tissue N concentration between treatments. P concentration and uptake of wheat, however, were generally reduced by nematode. It appears that the enhancement of plant growth and nitrogen uptake is attributed to the enhancement of nitrogen mineralization induced by nematode feeding on bacteria, and the reduction of phosphorous uptake is the result of weak root status and competition by bacteria immobilization.展开更多
[ Objective ] The paper was to study the effects of anti-nematode preparations with different mechanisms on changes of enzyme systems and membrane permeability of tomato leaves, so as to provide reference basis for ef...[ Objective ] The paper was to study the effects of anti-nematode preparations with different mechanisms on changes of enzyme systems and membrane permeability of tomato leaves, so as to provide reference basis for effective control of soil root-knot nematode in greenhouse. [ Method] With tomato seedlings af- fected by root-knot nematode as material, changes of superoxide dismutase（SOD）, peroxidase（ POD）, relative conductivity and malondialdehyde （MDA） in toma- toes were tested after the seedling soil was treated by preparations of Wuxianmei, Hailvsu, Duxiandna and Avermectin. [ Result] After treated by different prepara- tions, SOD and POD activity of tomato leaves were higher than control, and that treated by Wuxianmei was the highest. In addition to Duxiandna, the relative con- ductivity and MDA content of other treatments were significantly lower than control. When tomatoes were planted for 70 d, the effect of Avermectin against reot-knot nematode Was the best of 66.3%. [ Conclusion] After tomatoes were infected by root-knot nematode, different preparation treatments all had certain control effect, which made the physical indicators of tomato have obvious change. Integrated control of multiple preparations in greenhouse was beneficial to control soil root-knot nematode.展开更多
This study focused,for the first time,on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake(MSC).The nematostatic potential of sonicated seed cake was examined...This study focused,for the first time,on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake(MSC).The nematostatic potential of sonicated seed cake was examined against the second-stage juveniles(J2s)of root-knot nematode,Meloidogyne javanica.The results show that a 35 ppm(parts per million)concentration of a sonicated extract(SE)sample of MSC caused 65%J2s mortality at 18 h exposure period in vitro.It also significantly suppressed the root-knot index(RKI=0.94)in tomato roots.The lethal concentration values for SE were 51.76,29.79,and 13.34 ppm,respectively,at 6,12,and 18 h of the exposure period,and the lethal concentration values for the non-sonicated extract(NSE)sample were 116.95,76.38,and 55.59 ppm,respectively,at similar exposure time.Sinapine and gluconapin were identified as the major compounds in ultrasonic-assisted MSC.Because of the high extraction efficiency of metabolites in the SE,all treat‐ments of SE were shown to be antagonistic to J2s.Thus,this study of ultrasonication activity-based profiling of MSC may help generate target-based compounds at a scale relevant to the control of disease caused by nematodes in economic crops.展开更多
Synergism between pesticide and fertilizer in controlling root-knot nematode was investigated by field randomized block test. The results showed that the best control efficiency was shared by 0.5% abamectin and 25% mi...Synergism between pesticide and fertilizer in controlling root-knot nematode was investigated by field randomized block test. The results showed that the best control efficiency was shared by 0.5% abamectin and 25% mixed pesticide （abamectin and carbosulfan）, 24.1% and 28.0%, respectively. The positive effect was found by synergism between pesticide and fertiUzer in controlling reot-knot nematode. The economic benefit and agricultural benefit were gained by controlling root-knot nematodes. The results suggested that the agricultural and ecological benefit could be gained through the integration of agricultural practice and chemical technology in controlling root-knot nematode.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
Agricultural research made in recent years has found that many bacterial organisms act like biological control agents with minimal impact on the environment. These microorganisms and their toxic metabolites should be ...Agricultural research made in recent years has found that many bacterial organisms act like biological control agents with minimal impact on the environment. These microorganisms and their toxic metabolites should be included in those which are acceptable to qualify a product as organic or integrated and enjoy all the benefits that entails. Hence, interest in the use of microorganisms as biological agents to protect crop plants against plant parasitic nematodes has been increasing. This study investigated the ability of.Pseudomonas oryzihabitans symbiotically associated with the entomopathogenic nematode Steinernema abbasi as a bioagent against plant parasitic nematodes which infected tomato crop. The bacterium is particularly effective against root-knot nematode in vitro affecting the behavior and mobility of root-knot nematode juveniles. Also, studies in planta demonstrated the efficacy of P. oryzihabitans by preventing tomato root system by invasion of juveniles of Meloidogynejavaniea when bacterial cells were applied to the root system before nematodes. This efficacy is dependent on bacterial cell concentration used and the time of the nematode exposure. However, a better nematode control might be achieved with multiple applications of the biocontrol agent. Furthermore, the results of this study provide evidence that the bacterium P. oryzihabitans produces metabolites, which have nematostatic effects.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
Geostatistics combined with GIS was applied to assess the spatial distribution of nematode trophic groups following two contrasting soil uses in the black soil region of Northeast China. Two plots, one with fallow for...Geostatistics combined with GIS was applied to assess the spatial distribution of nematode trophic groups following two contrasting soil uses in the black soil region of Northeast China. Two plots, one with fallow for 12 years and the other cultivated, were marked on regular square grids with 2-m spacing. Soil samples were collected from each sampling point, nematodes were extracted from these samples and classified into four trophic groups: bacterivores, fungivores, plant parasites, and omnivores/predators. The numbers of total nematodes and trophic groups analyzed had normal distributions on both fallow and cultivated plots. The absolute abundances of total nematodes and trophic groups were observed to be much more homogeneous on cultivated plot than on fallow one. Geostatistical analysis showed that the densities of total nematodes and trophic groups on both fallow and cultivated plots exhibited spatial dependence at the sampled scale and their experimental semivariograms were adjusted to a spherical or exponential model, except those of bacterivores and fungivores on cultivated plot. The spatial distribution of nematode trophic groups was found to be different for the two land uses, indicating that cultivation changed the native condition for soil nematode activities.展开更多
To determine the effect of agricultural management on the dynamics and functional diversity of soil nematode communities in a carrot field at Kibbutz Ramat Hakovesh, Israel, soil samples from 0-10 cm and 10-20 cm dept...To determine the effect of agricultural management on the dynamics and functional diversity of soil nematode communities in a carrot field at Kibbutz Ramat Hakovesh, Israel, soil samples from 0-10 cm and 10-20 cm depths were collected during the growing season of carrot. Indices were used to compare and assess the response of soil free-living nernatode communities to agricultural management. Eighteen nematode families and 20 genera were observed during the growing period, with Cephalobus, Rhabditidae, Aphelenchus, Tylenchus, and Dorylaimus being the dominant genera/families. During the planting, mid-season and post-harvest periods the total number of nematodes at both depths was significantly lower (P < 0.01) in the carrot treatment than in the control plots, while during the harvest period at both depths total nematodes and bacterivores were significantly higher in the treatment plots (P < 0.01). The values of the maturity index (MI) at both depths were found to be significantly lower in the treatment plots than in the control plots during the pre-planting period (P < 0.05). Overall, WI, MI and PPI were found to be more sensitive indicators than other ecological indices for assessing the response of nematode communities to agricultural management in a Mediterranean agroecosystem展开更多
While studies have focused on the use of biochar as soil amendment, little attention has been paid to its effect on soil fauna. The biochar was produced from slow pyrolysis of wheat straw in the present study. Four tr...While studies have focused on the use of biochar as soil amendment, little attention has been paid to its effect on soil fauna. The biochar was produced from slow pyrolysis of wheat straw in the present study. Four treatments, no addition (CK) and three rates of biochar addition at 2 400 (B1), 12 000 (B5) and 48 000 kg ha-1 (B20), were investigated to assess the effect of biochar addition to soil on nematode abundance and diversity in a microcosm trial in China. The B5 and B20 application significantly increased the total organic carbon and the C/N ratio. No significant difference in total nematode abundance was found among the treatments. The biochar addition to the soil significantly increased the abundance of fungivores, and decreased that of plant parasites. The diversity of soil nematodes was significantly increased by B1 compared to CK. Nematode trophic groups were more effectively indicative to biochar addition than total abundance.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.
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 Natural Science Foundation of China(31901858 and 31901859)。
文摘Soybean cyst nematode(SCN,Heterodera glycines)is a devastating pathogen that infects soybean(Glycine max L.Merrill)and disrupts soybean production worldwide.SCN infection upregulates or downregulates the expression of multiple genes in soybean.However,the regulatory mechanisms that underlie these changes in gene expression remain largely unexplored.N^(6)-methyladenosine(m^(6)A)methylation,one of the most prevalent mRNA modifications,contributes to transcriptional reprogramming during plant responses to pathogen infection.Nevertheless,the role of m^(6)A methylation in establishing compatible and incompatible soybean responses to SCN has not previously been studied.Here,we performed transcriptome-wide m^(6)A profiling of soybean roots infected with virulent and avirulent populations of SCN.Compared with the compatible response,the incompatible response was associated with higher global m^(6)A methylation levels,as well as more differentially modified m^(6)A peaks(DMPs)and differentially expressed genes(DEGs).A total of 133 and 194 genes showed significant differences in both transcriptional expression and m^(6)A methylation levels in compatible and incompatible interactions;the most significantly enriched gene ontology terms associated with these genes were plant–pathogen interaction(compatible)and folate biosynthesis(incompatible).Our findings demonstrate that the m^(6)A methylation profiles of compatible and incompatible soybean responses are distinct and provide new insights into the regulatory mechanism underlying soybean response to SCN at the post-transcriptional modification level,which will be valuable for improving the SCN-resistant breeding.
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.
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This study was financially supported by the National Natural Science Foundation of China(31801717)the Major Science and Technology Projects in Henan Province,China(221100110300)+2 种基金the Special Fund for Young Talents in Henan Agricultural University,China(30500663)the Opening Foundation of the National Key Laboratory of Crop Science on Wheat and Maize,China(SKL2021KF06)the HAU grant for Collaborative Crop Science Research,China(CCSR2022-1)。
文摘The occurrence, distribution, and rapid molecular detection technology of Heterodera zeae Koshy et al. 1971, have been reported in China. We explored the biological characteristics of H. zeae sampled in Henan Province, China to understand its interaction with plants. Cysts and second-stage juveniles(J2s) were identified under an optical and scanning electron microscope, internal transcribed spacer(ITS) phylogenetic tree, and sequence characterized amplified region(SCAR)-PCR analyses. The optimum hatching temperatures of H. zeae were 30°C and 28°C, with cumulative hatching rates of 16.5 and 16.1%, respectively, at 30 days post-hatching(dph). The hatching rate of H. zeae eggs was improved by 20-and 50-time maize soil leachate and root juice, and 10-time root exudates. The hatching rate in 10-time root exudates was the highest(25.9%). The 10-time root exudates of maize and millet produced the highest hatching rate at 30 dph(25.9 and 22.9%, respectively), followed by wheat(19.9%), barley(18.3%), and rice(17.6%). Heterodera zeae developed faster in maize than in other crops. Fourth-stage juveniles(J4s) were detected in maize roots 8 days post-inoculation(dpi) at 28°C but not in other crops. Combined with hatching tests, the Huang–Huai–Hai summer maize region and the south and central-southwest mountainous maize areas are highly suitable for H. zeae in China. This is the first systematically study of the hatching and infection characteristics on different plant hosts of corn cyst nematode H. zeae in temperate regions. This study laid a theoretical foundation for the rapid spread and high environmental adaptability of corn cyst nematode.
基金funded by the National Science Foundation of China and project(Grant No.G1999043407)supported by the National Key Basic Research Special Funds(Nos.30170744and G1999043407)
文摘Soil nematode communities were investigated in the Changbai Mountain in Broad-leaved Korean Pine forest, Korean Pine and spruce-fix mixed forest, Dark Coniferous forest, Erman＇s birch forest and Alpine tundra along different altitude gradients from 762 m to 2 200 m a.s.l. Soil animal samples were collected from the litter layer and the soil depth of 0-5 cm, 5-10 cm and 10-20 cm at each site in the spring of 2001 and 2002. In total 27 nematode families and 60 genera were observed. The dominant genera were Plectus Bastian and Tylenchus Bastian and most of them live in litter layer. The total number of soil nematode was significantly correlated with soil moisture （r=0.357; p〈0.01）. Nematodes were classified in bacterivores, fungivores, plant parasites, omnivores-predators, and omnivores according to known feeding habitats or stoma and esophageal morphology. Species richness of fungivorous nematode was higher than others in different vegetation communities and soil depths. The total number of soil nematode and trophic groups varied significantly （o〈0.05） in response to different soil depths. The fungivore/bacterivore ratio （F/B） and the ratio of （fungivores ＋ bacterivores）/plant-parasites （WI） also changed significantly （p〈0.05） in different soil depths. In conclusion, soil moisture is proved to be one of the most important variables affecting nematode density and trophic composition, and the altitude gradient does not significantly affect the ecological indices of soil nematode such as trophic diversity （TD） and the Shannon index （H＇）.
基金Supported by Science and Technology Plan Project of Yunnan Provincial Tobacco Company(2012YN06)National Natural Science Foundation of China(31160361)~~
文摘Tobacco root-knot nematode disease has caused severe damage in Geng- ma County, Yunnan Province. In order to identify the pathogenic factors of the tobac- co root-knot nematode disease in this county, the pathogenic nematodes, hosts and environment of tobacco fields in Mengsa, Hepai and Sipaishan 3 main tobacco-grow- ing towns in Gengma County were investigated and analyzed based on the local re- lated field survey on tobacco root-knot nematode disease in this county in 2012. The results showed the incidence and severity of the tobacco root-knot nematode disease were all higher than those of previous years. dominant pathogens of the tobacco root-knot The species identification showed the nematode disease were Meloidogyne arenaria and M. javanica in Gengma County. The lacking of disease-resistant culti- vars, poor management and climatic anomaly were the main causes of the tobacco root-knot nematode disease in Gengma. According to the occurrence characteristics of the disease, the agricultural prevention-based control measures were proposed.
基金Supported by National Natural Science Foundation of China ( 30940050)Natural Science Foundation of Hebei Province ( C2006000559+2 种基金 C2009000868) Commission of Science Technology of Hebei Province ( 06547005D-3,09220103D-11)Educational Commission of Hebei Province( Z2008114)~~
文摘[ Objective] The paper was to identify endophytic bacillus BHL3501 from wild soybean and its inhibitory effect against soybean cyst nematode. [ Meth- od] Through morphological characteristic, physiological and biochemical characteristics and 16S rDNA analysis, a strain of endophytic bacterium BHL3501 with ne- maticidal activity isolated and screened from the root of wild soybean was identified, the effects of BHL3501 metabolite solutions with different dilution multiples on egg hatching and activity of 2rd instar juvenile of soybean cyst nematode were also studied. [ Result ] BHL3501 strain was preliminarily identified to be Bacillus sp.. The relative inhibitory rate of its original fermentation broth on egg hatching of soybean cyst nematode after 24 h was 98.3% ; the relative inhibitory rate under 10- time diluted solution treatment was 79.5%, which had significant difference with sterile water control. The corrected mortality rate of 24 instar juvenile was 93.1% after treated by original fermentation broth for 24 h, the treatments of all diluted solutions had significant difference with sterile water control. [ Conclusion ] BHL3501 metabolites had strong inhibitory effect against egg hatching of soybean cyst nematode, which also had strong toxic effect on its 2nd instar juvenile.
基金Supported by Science and Technology Project from Shaanxi Provincial Department of EducationMajor Scientific and Technological In-novation Project of Shaanxi Province (2009ZKC08-09 )Science and Technology Project of Wenzhou (H20080045)~~
文摘Present mature plants hydroponic technology was used,combined with some excellent characteristics,such as growth conditions was easy to control and process of root growth was easy to continuously observe,the nematicidal activity of 5 kinds of Chinese herbs extracts and the compound solution of Avermectin,with strong contact toxicity effect indoor,was systematically studied and investigated the affection on the root-knot nematode parasitized on the cucumber seeding stage. It is found that under the premise of no influence on root growth of cucumber,extracts from Picrorhiza scrophulariiflora and Punica granatum showed strong prevention and nematicidal activity,and had the similar efficacy of Avermectin; while the extracts from Cibotium barometz,Aucklandia lappa Decne and Fructus cnidii showed low nematicidal activity and various degrees inhibition effect on plant growth.
基金Project (No. 39570134 and 39970419) supported by the National Natural Science Foundation of China.
文摘A 40-day gnotobiotic microcosm experiment was carried out to quantify the effect of hastenal-feeding nematode on plant growth and nutrient absorption. The results showed that inoculation of bacterial-feeding nematode Protorhabditis sp. stimulated the growth of wheat (Triticum aestivum) and the uptake of N. By the end of the 40-day incubation wheat biomass and N uptake in the treatment with nematode and bacteria (Pseudomonas sp.) increased by 6.5% and 5.9%, respectively, compared with bacteria alone treatment. The presence of nematode mainly accelerated the growth of aboveground of wheat, while it slightly inhibited the root development. There was little difference in plant tissue N concentration between treatments. P concentration and uptake of wheat, however, were generally reduced by nematode. It appears that the enhancement of plant growth and nitrogen uptake is attributed to the enhancement of nitrogen mineralization induced by nematode feeding on bacteria, and the reduction of phosphorous uptake is the result of weak root status and competition by bacteria immobilization.
基金Supported by Transformation and Promotion Projects of Agriculture Science and Technology Achievements of Tianjin City"Integration and Demonstration of Integrated Control Technology of Greenhouse Vegetable Fields with Continuous Cropping Obstacles"(0804140)Basic Application and Cutting-edge Technology Research Projects of Tianjin City"Risk Assessment and Regulation Research of Nitrogen and Phosphorus Non-point Source Pollution in Facility Agriculture"(09JCYBJC08600)~~
文摘[ Objective ] The paper was to study the effects of anti-nematode preparations with different mechanisms on changes of enzyme systems and membrane permeability of tomato leaves, so as to provide reference basis for effective control of soil root-knot nematode in greenhouse. [ Method] With tomato seedlings af- fected by root-knot nematode as material, changes of superoxide dismutase（SOD）, peroxidase（ POD）, relative conductivity and malondialdehyde （MDA） in toma- toes were tested after the seedling soil was treated by preparations of Wuxianmei, Hailvsu, Duxiandna and Avermectin. [ Result] After treated by different prepara- tions, SOD and POD activity of tomato leaves were higher than control, and that treated by Wuxianmei was the highest. In addition to Duxiandna, the relative con- ductivity and MDA content of other treatments were significantly lower than control. When tomatoes were planted for 70 d, the effect of Avermectin against reot-knot nematode Was the best of 66.3%. [ Conclusion] After tomatoes were infected by root-knot nematode, different preparation treatments all had certain control effect, which made the physical indicators of tomato have obvious change. Integrated control of multiple preparations in greenhouse was beneficial to control soil root-knot nematode.
基金the University Grants Com‐mission(UGC-BSR Research Start-up-Grant:F30-409/2018),India.
文摘This study focused,for the first time,on the effect of ultrasonic features on the extraction efficiency of secondary metabolites in mustard seed cake(MSC).The nematostatic potential of sonicated seed cake was examined against the second-stage juveniles(J2s)of root-knot nematode,Meloidogyne javanica.The results show that a 35 ppm(parts per million)concentration of a sonicated extract(SE)sample of MSC caused 65%J2s mortality at 18 h exposure period in vitro.It also significantly suppressed the root-knot index(RKI=0.94)in tomato roots.The lethal concentration values for SE were 51.76,29.79,and 13.34 ppm,respectively,at 6,12,and 18 h of the exposure period,and the lethal concentration values for the non-sonicated extract(NSE)sample were 116.95,76.38,and 55.59 ppm,respectively,at similar exposure time.Sinapine and gluconapin were identified as the major compounds in ultrasonic-assisted MSC.Because of the high extraction efficiency of metabolites in the SE,all treat‐ments of SE were shown to be antagonistic to J2s.Thus,this study of ultrasonication activity-based profiling of MSC may help generate target-based compounds at a scale relevant to the control of disease caused by nematodes in economic crops.
基金Supported by Yunnan Tobacco Company Program(2015YN192014YN25)~~
文摘Synergism between pesticide and fertilizer in controlling root-knot nematode was investigated by field randomized block test. The results showed that the best control efficiency was shared by 0.5% abamectin and 25% mixed pesticide （abamectin and carbosulfan）, 24.1% and 28.0%, respectively. The positive effect was found by synergism between pesticide and fertiUzer in controlling reot-knot nematode. The economic benefit and agricultural benefit were gained by controlling root-knot nematodes. The results suggested that the agricultural and ecological benefit could be gained through the integration of agricultural practice and chemical technology in controlling root-knot nematode.
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.
文摘Agricultural research made in recent years has found that many bacterial organisms act like biological control agents with minimal impact on the environment. These microorganisms and their toxic metabolites should be included in those which are acceptable to qualify a product as organic or integrated and enjoy all the benefits that entails. Hence, interest in the use of microorganisms as biological agents to protect crop plants against plant parasitic nematodes has been increasing. This study investigated the ability of.Pseudomonas oryzihabitans symbiotically associated with the entomopathogenic nematode Steinernema abbasi as a bioagent against plant parasitic nematodes which infected tomato crop. The bacterium is particularly effective against root-knot nematode in vitro affecting the behavior and mobility of root-knot nematode juveniles. Also, studies in planta demonstrated the efficacy of P. oryzihabitans by preventing tomato root system by invasion of juveniles of Meloidogynejavaniea when bacterial cells were applied to the root system before nematodes. This efficacy is dependent on bacterial cell concentration used and the time of the nematode exposure. However, a better nematode control might be achieved with multiple applications of the biocontrol agent. Furthermore, the results of this study provide evidence that the bacterium P. oryzihabitans produces metabolites, which have nematostatic effects.
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.
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No. G1999011804-04) the Foundation of Knowledge Innovation Program of IAE-CAS (No. SCXMS0105).
文摘Geostatistics combined with GIS was applied to assess the spatial distribution of nematode trophic groups following two contrasting soil uses in the black soil region of Northeast China. Two plots, one with fallow for 12 years and the other cultivated, were marked on regular square grids with 2-m spacing. Soil samples were collected from each sampling point, nematodes were extracted from these samples and classified into four trophic groups: bacterivores, fungivores, plant parasites, and omnivores/predators. The numbers of total nematodes and trophic groups analyzed had normal distributions on both fallow and cultivated plots. The absolute abundances of total nematodes and trophic groups were observed to be much more homogeneous on cultivated plot than on fallow one. Geostatistical analysis showed that the densities of total nematodes and trophic groups on both fallow and cultivated plots exhibited spatial dependence at the sampled scale and their experimental semivariograms were adjusted to a spherical or exponential model, except those of bacterivores and fungivores on cultivated plot. The spatial distribution of nematode trophic groups was found to be different for the two land uses, indicating that cultivation changed the native condition for soil nematode activities.
基金Project partly supported by the Fred and Barbara Kort Sino-Israel Postdoctoral Fellowship
文摘To determine the effect of agricultural management on the dynamics and functional diversity of soil nematode communities in a carrot field at Kibbutz Ramat Hakovesh, Israel, soil samples from 0-10 cm and 10-20 cm depths were collected during the growing season of carrot. Indices were used to compare and assess the response of soil free-living nernatode communities to agricultural management. Eighteen nematode families and 20 genera were observed during the growing period, with Cephalobus, Rhabditidae, Aphelenchus, Tylenchus, and Dorylaimus being the dominant genera/families. During the planting, mid-season and post-harvest periods the total number of nematodes at both depths was significantly lower (P < 0.01) in the carrot treatment than in the control plots, while during the harvest period at both depths total nematodes and bacterivores were significantly higher in the treatment plots (P < 0.01). The values of the maturity index (MI) at both depths were found to be significantly lower in the treatment plots than in the control plots during the pre-planting period (P < 0.05). Overall, WI, MI and PPI were found to be more sensitive indicators than other ecological indices for assessing the response of nematode communities to agricultural management in a Mediterranean agroecosystem
基金Supported by the National Basic Research Program (973 Program) of China (No. 2011CB100504)the Knowledge Innovation Program of Chinese Academy of Sciences (No. KZCX2-YW-Q1-07)the Bluemoon Foundation, USA
文摘While studies have focused on the use of biochar as soil amendment, little attention has been paid to its effect on soil fauna. The biochar was produced from slow pyrolysis of wheat straw in the present study. Four treatments, no addition (CK) and three rates of biochar addition at 2 400 (B1), 12 000 (B5) and 48 000 kg ha-1 (B20), were investigated to assess the effect of biochar addition to soil on nematode abundance and diversity in a microcosm trial in China. The B5 and B20 application significantly increased the total organic carbon and the C/N ratio. No significant difference in total nematode abundance was found among the treatments. The biochar addition to the soil significantly increased the abundance of fungivores, and decreased that of plant parasites. The diversity of soil nematodes was significantly increased by B1 compared to CK. Nematode trophic groups were more effectively indicative to biochar addition than total abundance.
