[Objectives]To investigate the chemical composition,antioxidant property,and nematicidal activity of Cucumis metuliferus and establish a theoretical foundation for the development of botanical nematicides.[Methods]The...[Objectives]To investigate the chemical composition,antioxidant property,and nematicidal activity of Cucumis metuliferus and establish a theoretical foundation for the development of botanical nematicides.[Methods]The compounds were isolated and purified using silica gel,reversed-phase medium,low-pressure gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.Their identification was based on physicochemical properties,various spectral analyses,and data reported in the literature.Subsequently,the nematicidal and antioxidant activities of the isolated compounds were evaluated.[Results]A total of four compounds were isolated from C.metuliferus,which were identified as isovitexin-2″-O-glucoside(compound 1),9E,11E-(13-oxo)tridecadienoic acid(compound 2),2E,4E-tridecadienedioic acid(compound 3),and 9E,11E-(13-hydroxy)tridecadienoic acid(compound 4).Compound 1 demonstrated a notable degree of antioxidant activity,achieving a DPPH scavenging rate of 49.40%at a mass concentration of 1 mg/mL.Additionally,compounds 1,3,and 4 exhibited varying levels of nematicidal activity.Specifically,compound 1 displayed strong nematicidal activity at a concentration of 2.0 mg/mL,resulting in a mortality rate of 90.5%against nematodes.Furthermore,compounds 3 and 4 achieved a mortality rate of 100%against nematodes at a concentration of 0.25 mg/mL.[Conclusions]This study reports the first isolation of four compounds:isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,2E,4E-tridecadienedioic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid from C.metuliferus.Notably,2E,4E-tridecadienedioic acid and 9E,11E-(13-oxo)tridecadienoic acid are identified as novel natural products.Among these compounds,isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid exhibit nematicidal activity,whereas isovitexin-2″-O-glucoside demonstrates antioxidant properties.展开更多
[Objective] The nematicidal activity of plant extracts was investigated. We aimed to explore a kind of botanical pesticide to control Hirschmanniella spp. [Method] The Chuanxiong （root）, agrimony （whole plant）, co...[Objective] The nematicidal activity of plant extracts was investigated. We aimed to explore a kind of botanical pesticide to control Hirschmanniella spp. [Method] The Chuanxiong （root）, agrimony （whole plant）, cocklebur （grain）, basil （leaves）, ragweed （stems and leaves）, green onion （root）, garlic （tuber）, Yuzhu （leaves）, marshpeper smartweed （whole plant）, horseweed （aboveground stems and leaves） were dried, grinded and sieved. The powders were then extracted by ethanol at room temperature for 24 h. The extract solutions were filtered through fil- ter pater. The obtained plant extracts were then diluted to determine their nematici- dal activities. [Result] The Chuanxiong extract had the highest nematicidal activity, followed by cocklebur extract, agrimony extract, basil extract, garlic extract, ragweed extract. The horseweed extract had the lowest nematicidal activity. [Conclusion] The Chuanxiong and other plants were natural, and they had a good environmental compatibility. They could be developed as botanical pesticides against Hirschman- niella spp.展开更多
The total synthesis of （＋）-8-（3-methylbut-2-enyl）-2-phenyl-2,3-dihydrochromen-4-one and （±）-2-（4-hydroxyphenyl）-8-（3- methylbut-2-enyl）-2,3-dihydrochromen-4-one was first achieved through C-prenylation...The total synthesis of （＋）-8-（3-methylbut-2-enyl）-2-phenyl-2,3-dihydrochromen-4-one and （±）-2-（4-hydroxyphenyl）-8-（3- methylbut-2-enyl）-2,3-dihydrochromen-4-one was first achieved through C-prenylation, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxyace- tophenone, with total yield of 20 and 16.3%. All structures of new compounds were confirmed by IR, 1H NMR and MS. 2009 Jin Hui Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.展开更多
A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Me...A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L. Among the tested compounds, A10 and A11 exhibited 100% inhibition rates. In addition, the molecular docking results indicated that both compound A10 and A11 interacts with amino acid residue Tyr121, Trp279, Tyr70, Trp84 and Phe330 of ACh E via hydrogen bond and p–p stacking. This investigation suggested that the chromone containing substituted pyrazole scaffold could be further optimized to explore novel, high-bioactivity nematicidal leads.展开更多
In this study, nano-capsules of lansiumamide B （NCLB） was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B （LB）. An optimal formulation was gained by orthog...In this study, nano-capsules of lansiumamide B （NCLB） was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B （LB）. An optimal formulation was gained by orthogonal experiment design based on the encapsulation efficiency （E, %） value. The optimized NCLB were spherical and uniform under transmission electron microscopy （TEM）. The mean particle size, zeta potential and E, were （38.50~0.64） nm, （-70.5~0.76） mV and （95.13± 1.16）%, respectively. The release profile indicated that the accumulated release of LB in NCLB reached up to 82% within 96 h. Effects of NCLB against Bursaphelenehus xylophilus and J2 ofMeloidogyne incognita were reported in this paper. The nematicidal activity of NCLB has been remarkably increased, with LCs0 values of 2.1407 mg L-1 and 19.3608 mg L-1, respectively, at 24 h after treatment. The disease progression and the average number of root knots of Ipomoea aquatica were 1.50 and 7.25, respectively, in the treatment of NCLB, at concentration of 200 mg L-1 significantly lower than the treatment of LB and ethoprophos. Compared to control, the treatments of NCLB, LB and ethoprophos leaded the disease progression to drop 68.42, 36.84 and 26.32%, respectively, and caused the average number of root knots to fall 83.94, 78.03 and 63.66%. These results suggested that NCLB, as a novel nematicides formulation, performed more efficient and longer effective maintenance against plant parasitic nematodes.展开更多
To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structur...To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structure diversity of the new skeleton. Their inhibitory activities in vivo were evaluated against Meloidogyne incognita. The newly prepared compounds A6, A8, A21, A28 and A38 exhibited more than 50% inhibition at the concentration of 20 mg/L. Especially compound A6 displayed 71.4% inhibition against Meloidogyne incognita at the concentration of 20 mg/L. The nematicidal activities varied significantly depending on the types and positions of the substituents, which provided guidance for further structure modification.展开更多
Nematodes are serious constraints of crop production worldwide. However, the traditional nematicides suffer from the side-effects, including environmental and human toxicity. Herein, more than 70 novel piperazinedione...Nematodes are serious constraints of crop production worldwide. However, the traditional nematicides suffer from the side-effects, including environmental and human toxicity. Herein, more than 70 novel piperazinedione derivatives based on the natural product Barettin were synthesized and evaluated against the root-knot nematode Meloidogyne incognita（M. incognita）. While most of synthesized compounds exhibited certain nematicidal activity at high concentration, the best one showed a nematicidal activity of 75% at 2.4 mmol/L.展开更多
The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel c...The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita（5.1 mmol/L）, Ditylenchus destructor（3.7 mmol/L）, Bursaphelenchus mucronatus（6.4 mmol/L）, Bursaphelenchus B. xylophilus（2.5 mmol/L） and Aphelenchoides besseyi（3.1 mmol/L）,respectively. A brief investigation on the structure–activity relationships（SAR） revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.展开更多
C. bonariensis (L.) Cronq. known as hairy fleabane was first described in Argentina but it is now widely spread through most warmer regions of Europe, Africa, Asia, the Caribbean and Central America. In this work, a c...C. bonariensis (L.) Cronq. known as hairy fleabane was first described in Argentina but it is now widely spread through most warmer regions of Europe, Africa, Asia, the Caribbean and Central America. In this work, a chemical analysis by liquid and gas chromatography coupled with mass spectrometry of the whole plant, aerial part, flowers and roots extracts of C. bonariensis harvested in Togo (West Africa) was carried out. Two acetylenic compounds Lachnophyllum ester and limonene were identified as the main components of essential oils while Lachnophyllum and Matricaria lactones were dominant in chloroform extracts. Based on the plant chemical compositions, essential oils and chloroform extracts were tested on cowpea weevil Callosobruchus maculatus adults which are considered as one of the most cosmopolitan pests of stored beans, and on freshly hatched second-stage juveniles of root-knot nematode Meloidogyne incognita. Results showed that the whole plant essential oil demonstrated an LC<sub>50/24h</sub> value of 1.75 μL oil/L air on C. maculatus while at 3.91 μL oil/L air, it showed 100% mortality. Furthermore, the plant root chloroform extracts partitioned in diethyl ether-hexane mixture showed the strongest nematicidal activity with an LC<sub>50/72h</sub> value of 0.47 mg/mL. Our findings suggest that the widely diffused plant C. bonariensis and its acetylenic constituents could be considered as potent botanical insecticidal and nematicidal agents.展开更多
Plant-parasitic nematodes cause substantial economic losses to global agriculture yearly.The use of nematicides is an effective way of controlling plant-parasitic nematodes.However,the long-term use of traditional org...Plant-parasitic nematodes cause substantial economic losses to global agriculture yearly.The use of nematicides is an effective way of controlling plant-parasitic nematodes.However,the long-term use of traditional organophosphorus and carbamate chemical nematicides can lead to increased nematode resistance.With the increasing awareness of the necessity for the protection of the environment and human health,highly toxic nematicides no longer meet the developmental requirements of modern agriculture.Recently,many studies have been undertaken on the isolation and nematicidal activity of natural products against plant-parasitic nematodes and Caenorhabditis elegans.As an important model nematode,C.elegans plays a vital reference role in studying plant-parasitic nematodes regarding nematicidal activity,metabolic mechanism,and modes of action and target.We reviewed the latest research progress of natural nematicidal active compounds against plantparasitic nematodes and C.elegans over the past ten years,discussed the structure-activity relationship and mechanism of action,and examined the development and application of natural nematicidal active compounds.展开更多
Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,orig...Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72 hvalue reached 3.20 mg/L in vitro and the inhibition rate was 100.00%at 40 mg/L in the matrix.The structure-activity relationship of synthesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.展开更多
Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchufus semi...Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchufus semipenetruns in vitro and in vivo. Compounds 20, 21, 35 and 39 showed excellent lethal activities after treatment for 48 h in vitro, with LC50 values of 13.4±1.8, 11.7±2.5, 13.7±2.4 and 13.31.1 mg.L-1, respectively, which were obviously superior to fosthiazate （49.1±2.8 mg.L-1） and avermectin （26.6±2.3 mg.L-1）. Compound 23. can effectively control the citrus nema- tode disease caused by T. semipenetruns at 200 mg.L-1 in vivo with （68±3）% inhibitory effect, which was even better than that of avermectin （（63±2）%）. The CoMFA and CoMSIA models of three-dimensional quantitative structure-activity relationships （3D-QSARs） were established. The compound 33 was designed based on the 3D-QSAR models with more vigorous nematicidal activities in vitro （LC50：9.8±1.4 mg.L-1） and in vivo （（70±5）%）. These results demonstrated that compound 33 can be considered as a potential nematicide.展开更多
Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that...Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that HDZ-9-47 parasitized eggs of M.incognita within 7 days.In vitro,the culture filtrate of HDZ-9-47 caused 97.0%mortality of second-stage juveniles（J2s）of M.incognita and inhibited more than 50%egg hatching.In the field,compared with the control,the rootknot index and J2s density in the treatment of drench the broth contained 1012 HDZ-9-47 spores were respectively reduced by 51.1 and 80.7%at 90 days post transplantation,which were better than that in other application doses and methods.In addition,reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%,respectively,better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.And tomato yield also increased by 16.1%.Together,our results suggest that HDZ-9-47 could be an effective biocontrol agent of M.incognita,and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M.incognita control.展开更多
The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas,and nematicides are neither ecofriendly nor cost effective.More acceptable biological agents are r...The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas,and nematicides are neither ecofriendly nor cost effective.More acceptable biological agents are required for controlling this destructive pathogen.In this study,the biocontrol potential of Aspergillus welwitschiae AW2017 was investigated in laboratory and greenhouse experiments.The in vitro ovicidal and larvicidal activities of A.welwitschiae metabolites were tested on M.graminicola in laboratory experiments.The effect of A.welwitschiae on the attraction of M.graminicola to rice and the infection of rice by M.graminicola was evaluated in a greenhouse.The bioagent AW2017 displayed good nematicidal potential via its ovicidal and larvicidal action.The best larvicidal activity was observed at a concentration of 5×AW2017,which caused an 86.2%mortality rate at 48 h post inoculation.The highest ovicidal activity was recorded at a concentration of 5×AW2017,which resulted in an approximately 47.3%reduction in egg hatching after 8 d compared to the control.Under greenhouse conditions,the application of A.welwitschiae significantly reduced the root galls and nematodes in rice roots compared to the control.At a concentration of 5×AW2017,juveniles and root galls in rice roots at 14 d post inoculation(dpi)were reduced by 24.5 and 40.5%,respectively.In addition,the attraction of M.graminicola to rice roots was significantly decreased in the AW2017 treatment,and the development of nematodes in the AW2017-treated plants was slightly delayed compared with that in the PDB-treated control plants.The results indicate that A.welwitschiae is a potential biological control agent against M.graminicola in rice.展开更多
In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inh...In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inhibitor(SDHI)fungicide developed by Bayer AG in Germany,has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action.In this paper,two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures.The structures were identified and characterized by 1H nuclear magnetic resonance(NMR),13C NMR,and high-resolution mass spectrometer(HRMS).The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 lgmL-1 in comparison with fluopyram,while the nematode mortality rate dropped sharply at 100μg·mL-1,except for compounds I-11 and II-6.In terms of fungicidal activity,compound I-9 was discovered to have an excellent inhibitory rate,and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.展开更多
Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine...Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine parameters which characterize the global and local reactivity on five molecules of the series. These compounds differ from one to another with the aryl groups. There are: 1-(2-methylimidazo[1,2-a]pyridin-3-yl)-3-phenylprop-2-en-1-one, 3-(4-fluorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-[4-(dimethylamino)phenyl]-1-(2-methylimidazo [1,2-a]pyridin- 3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one. All results lead to finding out that local nucleophilicity and electrophilicity of compounds are not substituent-dependant contrarily to their global nucleophilicity which prove to be more sensitive to the electron-donating character of the substituents. 3-[4-(Dimethylamino) phenyl]-1-(2-methylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one was identified as the unique nucleophile compound by global reactivity. Respectively, the carbon atoms C5 and C14 are the prediction sites of electrophilic and nucleophilic attacks in the molecular skeleton of both molecules. Identification of interactions centres on IPC series is of great importance for organic synthesis and medicinal chemistry where the molecular hybridization strategy is very often used to improve biological activities of interesting therapeutic systems.展开更多
Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents ...Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nematodes reproduction factor as compared to untreated infested soil.展开更多
Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the...Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers＇ fields infested with root-knot nematodes （A4eloidogvne javanica and Meloidogyne incognita）, at two sites in central Kenya （Maragua and Kirinyaga districts）, representing two contrasting group of farmers （low-input and high-input）. The trials aimed at evaluating the potential of using biological control agents （BCAs）, i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants （Crotalaria grahamiana and Tagetes minuta）, ＂＇trash burning＂ and chemical control （dazomet 98% = Basamid~ Granular） in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, ＂trash burning＂ and dazomet, significantly （P 〈 0.05） reduced the number of second-stage juveniles （J2s） of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant （P 〉 0.05） increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs （P. ehlamydosporia）, was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant （P 〉 0.05） increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.展开更多
Essential oils （EOs） from Rosemary, Rosmarinus officinalis （Lamiaceae）, Orange, Citrus sinensis （Rutaceae）, Lavandula, Lavandula angustifolia （Lamiaceae）, False Yellowhead, Dittrichia viscosa （Asteraceae） an...Essential oils （EOs） from Rosemary, Rosmarinus officinalis （Lamiaceae）, Orange, Citrus sinensis （Rutaceae）, Lavandula, Lavandula angustifolia （Lamiaceae）, False Yellowhead, Dittrichia viscosa （Asteraceae） and their major components were evaluated against root knot nematode, Meloidogyne incognita and Meloidogynejavanica. Second stage juveniles＇ （J2） paralysis and egg hatch inhibition were studied, while pulverized plant parts were tested for nematodes biological cycle arrest. All EOs paralyzed J2 and M. incognita were found more sensitive than M javanica with the EC50/4 days calculated at 250, 3,650 and 4,260 12g/mL for 1）. viscosa, L. angustifolia and R. officinalis, respectively. Similarly, all EOs inhibited nematodes egg hatch and D. viscosa exhibited the highest inhibition on egg hatch （100% inhibition at 5 μg/mL）. A significant influence of constituent terpenes （limonene, 1,8-cineole, linalool, camphor, L-borneol, caryophyllene oxide, β-eudesmol） dose and exposure time was indicated on egg hatch inhibition （56% to 100% at 500 μg/mL and 1,000 μg/mL）, while only β-eudesmol achieved paralysis of J2 and specifically against M. incognita （EC50/1d = 50μg/mL）. Interestingly, the most active botanical species arresting Meloidogyne spp. biological cycle in soil was C. sinensis （EC50 = 2 mg/g） and the most sensitive nematode species was M. javanica. The larvicidal and egg hatch inhibition activity holds promise towards the optimization of artificial terpene mixtures as novel and effective natural nematicides. Complex interactions of primary compounds and subsequent decomposition derivates compose efficacy profile of soil amendments.展开更多
The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were eval...The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.展开更多
基金Supported by Natural Science Foundation Project of Xinjiang Uygur Autonomous Region(2021D01B59)Youth Science and Technology Backbone Project of Xinjiang Academy of Agricultural Sciences(XJNKQ-2021011)+2 种基金General Program of Hainan Natural Science Foundation(319MS109)Major Science and Technology Program of Hainan Province(ZDKJ2021005)Specific Research Fund of the Innovation Platform for Academicians of Hainan Province(YSPTZX202141).
文摘[Objectives]To investigate the chemical composition,antioxidant property,and nematicidal activity of Cucumis metuliferus and establish a theoretical foundation for the development of botanical nematicides.[Methods]The compounds were isolated and purified using silica gel,reversed-phase medium,low-pressure gel Sephadex LH-20 column chromatography,and preparative high-performance liquid chromatography.Their identification was based on physicochemical properties,various spectral analyses,and data reported in the literature.Subsequently,the nematicidal and antioxidant activities of the isolated compounds were evaluated.[Results]A total of four compounds were isolated from C.metuliferus,which were identified as isovitexin-2″-O-glucoside(compound 1),9E,11E-(13-oxo)tridecadienoic acid(compound 2),2E,4E-tridecadienedioic acid(compound 3),and 9E,11E-(13-hydroxy)tridecadienoic acid(compound 4).Compound 1 demonstrated a notable degree of antioxidant activity,achieving a DPPH scavenging rate of 49.40%at a mass concentration of 1 mg/mL.Additionally,compounds 1,3,and 4 exhibited varying levels of nematicidal activity.Specifically,compound 1 displayed strong nematicidal activity at a concentration of 2.0 mg/mL,resulting in a mortality rate of 90.5%against nematodes.Furthermore,compounds 3 and 4 achieved a mortality rate of 100%against nematodes at a concentration of 0.25 mg/mL.[Conclusions]This study reports the first isolation of four compounds:isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,2E,4E-tridecadienedioic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid from C.metuliferus.Notably,2E,4E-tridecadienedioic acid and 9E,11E-(13-oxo)tridecadienoic acid are identified as novel natural products.Among these compounds,isovitexin-2″-O-glucoside,9E,11E-(13-oxo)tridecadienoic acid,and 9E,11E-(13-hydroxy)tridecadienoic acid exhibit nematicidal activity,whereas isovitexin-2″-O-glucoside demonstrates antioxidant properties.
基金Supported by Science and Technology Project of Hunan Provincial Department of Education(11A059)Earmarked Fund for China Agriculture Research System(CARS19-05B)~~
文摘[Objective] The nematicidal activity of plant extracts was investigated. We aimed to explore a kind of botanical pesticide to control Hirschmanniella spp. [Method] The Chuanxiong （root）, agrimony （whole plant）, cocklebur （grain）, basil （leaves）, ragweed （stems and leaves）, green onion （root）, garlic （tuber）, Yuzhu （leaves）, marshpeper smartweed （whole plant）, horseweed （aboveground stems and leaves） were dried, grinded and sieved. The powders were then extracted by ethanol at room temperature for 24 h. The extract solutions were filtered through fil- ter pater. The obtained plant extracts were then diluted to determine their nematici- dal activities. [Result] The Chuanxiong extract had the highest nematicidal activity, followed by cocklebur extract, agrimony extract, basil extract, garlic extract, ragweed extract. The horseweed extract had the lowest nematicidal activity. [Conclusion] The Chuanxiong and other plants were natural, and they had a good environmental compatibility. They could be developed as botanical pesticides against Hirschman- niella spp.
基金the National Natural Science Foundation(No.20562010)Ministry of National Education(No.203143)for financial support
文摘The total synthesis of （＋）-8-（3-methylbut-2-enyl）-2-phenyl-2,3-dihydrochromen-4-one and （±）-2-（4-hydroxyphenyl）-8-（3- methylbut-2-enyl）-2,3-dihydrochromen-4-one was first achieved through C-prenylation, protection of phenolic hydroxyl group, aldol condensation, cyclization and deprotection starting from cheap benzaldehyde, 4-hydroxybenzaldehyde and 2-hydroxyace- tophenone, with total yield of 20 and 16.3%. All structures of new compounds were confirmed by IR, 1H NMR and MS. 2009 Jin Hui Yang. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.
基金financial supported by the National Natural Science Foundation of China (No. 21672061)National Key Research Program of China (No. 2017YFD0200505)Fundamental Research Funds for the Central Universities (No. 222201718004)
文摘A series of chromone derivatives containing substituted pyrazole were designed and synthesized.Preliminary bioassays showed that most of the synthesized compounds exhibited good nematicidal activity in vivo against Meloidogyne incognita at 10 mg/L. Among the tested compounds, A10 and A11 exhibited 100% inhibition rates. In addition, the molecular docking results indicated that both compound A10 and A11 interacts with amino acid residue Tyr121, Trp279, Tyr70, Trp84 and Phe330 of ACh E via hydrogen bond and p–p stacking. This investigation suggested that the chromone containing substituted pyrazole scaffold could be further optimized to explore novel, high-bioactivity nematicidal leads.
基金Guangzhou Science and Technology Plan Projects, Guangzhou, China(10C62101593)
文摘In this study, nano-capsules of lansiumamide B （NCLB） was prepared by the microemulsion polymerization method to improve the nematicidal efficacy of lansiumamide B （LB）. An optimal formulation was gained by orthogonal experiment design based on the encapsulation efficiency （E, %） value. The optimized NCLB were spherical and uniform under transmission electron microscopy （TEM）. The mean particle size, zeta potential and E, were （38.50~0.64） nm, （-70.5~0.76） mV and （95.13± 1.16）%, respectively. The release profile indicated that the accumulated release of LB in NCLB reached up to 82% within 96 h. Effects of NCLB against Bursaphelenehus xylophilus and J2 ofMeloidogyne incognita were reported in this paper. The nematicidal activity of NCLB has been remarkably increased, with LCs0 values of 2.1407 mg L-1 and 19.3608 mg L-1, respectively, at 24 h after treatment. The disease progression and the average number of root knots of Ipomoea aquatica were 1.50 and 7.25, respectively, in the treatment of NCLB, at concentration of 200 mg L-1 significantly lower than the treatment of LB and ethoprophos. Compared to control, the treatments of NCLB, LB and ethoprophos leaded the disease progression to drop 68.42, 36.84 and 26.32%, respectively, and caused the average number of root knots to fall 83.94, 78.03 and 63.66%. These results suggested that NCLB, as a novel nematicides formulation, performed more efficient and longer effective maintenance against plant parasitic nematodes.
基金financial supported by the National Natural Science Foundation of China(No. 21672061)National Key Research Program of China(Nos.2017YFD0200505 and 2018YFD0200105)the Fundamental Research Funds for the Central Universities(No. 222201718004)
文摘To explore new skeleton with nematicidal activity, a series of novel 1,2,3-benzotriazin-4-one derivatives containing piperazine as linker were synthesized and varied fragments were also introduced to increase structure diversity of the new skeleton. Their inhibitory activities in vivo were evaluated against Meloidogyne incognita. The newly prepared compounds A6, A8, A21, A28 and A38 exhibited more than 50% inhibition at the concentration of 20 mg/L. Especially compound A6 displayed 71.4% inhibition against Meloidogyne incognita at the concentration of 20 mg/L. The nematicidal activities varied significantly depending on the types and positions of the substituents, which provided guidance for further structure modification.
基金financially supported by the National Natural Science Foundation of China (No. 21572060)
文摘Nematodes are serious constraints of crop production worldwide. However, the traditional nematicides suffer from the side-effects, including environmental and human toxicity. Herein, more than 70 novel piperazinedione derivatives based on the natural product Barettin were synthesized and evaluated against the root-knot nematode Meloidogyne incognita（M. incognita）. While most of synthesized compounds exhibited certain nematicidal activity at high concentration, the best one showed a nematicidal activity of 75% at 2.4 mmol/L.
基金the National Natural Science Foundation of China(Nos.31070386,21302195 and 31300290)135 Key Cultivation Program of the Chinese Academy of Sciencesthe Province-Academy Cooperation Program of Henan Province of China(No.102106000021)for financial support
文摘The presence of hydroxyl groups at the C4 and C7 positions in coumarin backbone has been proposed as a potential modification site for providing excellent bioactivity according to previous studies. A series of novel coumarin derivatives were rationally designed and synthesized by use of a complex catalytic system for a targeted modification at the above sites. These derivatives were assayed for nematicidal activity. As predicted, the derivatization enhanced the activity of the coumarins against five nematodes.Compounds 7b, 9a, 10 c and 11 c showed significant strong nematicidal broad spectrum activity against all tested nematodes. Compound 10 c was the most effective with the lowest LC50 values against Meloidogyne incognita（5.1 mmol/L）, Ditylenchus destructor（3.7 mmol/L）, Bursaphelenchus mucronatus（6.4 mmol/L）, Bursaphelenchus B. xylophilus（2.5 mmol/L） and Aphelenchoides besseyi（3.1 mmol/L）,respectively. A brief investigation on the structure–activity relationships（SAR） revealed that the targeted modification by a C7 hydroxyl was optimum compared with that of a C4 hydroxyl and that the coupling chain length was crucial for the nematicidal activity.
文摘C. bonariensis (L.) Cronq. known as hairy fleabane was first described in Argentina but it is now widely spread through most warmer regions of Europe, Africa, Asia, the Caribbean and Central America. In this work, a chemical analysis by liquid and gas chromatography coupled with mass spectrometry of the whole plant, aerial part, flowers and roots extracts of C. bonariensis harvested in Togo (West Africa) was carried out. Two acetylenic compounds Lachnophyllum ester and limonene were identified as the main components of essential oils while Lachnophyllum and Matricaria lactones were dominant in chloroform extracts. Based on the plant chemical compositions, essential oils and chloroform extracts were tested on cowpea weevil Callosobruchus maculatus adults which are considered as one of the most cosmopolitan pests of stored beans, and on freshly hatched second-stage juveniles of root-knot nematode Meloidogyne incognita. Results showed that the whole plant essential oil demonstrated an LC<sub>50/24h</sub> value of 1.75 μL oil/L air on C. maculatus while at 3.91 μL oil/L air, it showed 100% mortality. Furthermore, the plant root chloroform extracts partitioned in diethyl ether-hexane mixture showed the strongest nematicidal activity with an LC<sub>50/72h</sub> value of 0.47 mg/mL. Our findings suggest that the widely diffused plant C. bonariensis and its acetylenic constituents could be considered as potent botanical insecticidal and nematicidal agents.
基金The authors are grateful to the National Key Research and Development Program of China(2018YFD0200100)for supporting the project.
文摘Plant-parasitic nematodes cause substantial economic losses to global agriculture yearly.The use of nematicides is an effective way of controlling plant-parasitic nematodes.However,the long-term use of traditional organophosphorus and carbamate chemical nematicides can lead to increased nematode resistance.With the increasing awareness of the necessity for the protection of the environment and human health,highly toxic nematicides no longer meet the developmental requirements of modern agriculture.Recently,many studies have been undertaken on the isolation and nematicidal activity of natural products against plant-parasitic nematodes and Caenorhabditis elegans.As an important model nematode,C.elegans plays a vital reference role in studying plant-parasitic nematodes regarding nematicidal activity,metabolic mechanism,and modes of action and target.We reviewed the latest research progress of natural nematicidal active compounds against plantparasitic nematodes and C.elegans over the past ten years,discussed the structure-activity relationship and mechanism of action,and examined the development and application of natural nematicidal active compounds.
基金financial supported by the National Natural Science Foundation of China(No.21672061)National Key Research Program of China(No.2018YFD0200105)+1 种基金supported by Innovation Program of Shanghai Municipal Education Commission(No.201701070002E00037)the Fundamental Research Funds for the Central Universities。
文摘Plant-parasitic nematodes are major threat for crop protection.The lack of nematicides with new mode of action and increasing resistance raises the need for novel nematicides.In order to seek new nematicidal lead,originating from the structure of chalcone,a series of fused ring compounds was obtained by ring closure design strategy.These compounds were modified further.The nematicidal activity against M.incognita of synthesized compounds was evaluated.The bioassay showed that compound 3 and some of its derivatives such as compounds 18,19,21,22,23,24 and 26 exhibited excellent nematicidal activity.Among them,compound 23 exhibited significant bioactivity.The LC50/72 hvalue reached 3.20 mg/L in vitro and the inhibition rate was 100.00%at 40 mg/L in the matrix.The structure-activity relationship of synthesized compounds was discussed in details.The influence of compound 23 on egg hatching,motility,and feeding behavior of C.elegans was also evaluated.
基金This work was financially supported by the National Key Re- search Development Program of China （2018YFD0200100） and the National Natural Science Foundation of China （No. 21672044） and Subsidy Project for Outstanding Key Laboratory of Guizhou Prov- ince in China （20154004）.
文摘Forty one novel 1,3,4-oxadiazole/thiadiazole thioether derivatives containing phenoxy moiety were designed and synthesized. Bioassay demonstrated that some of them showed remarkable activities against Tylenchufus semipenetruns in vitro and in vivo. Compounds 20, 21, 35 and 39 showed excellent lethal activities after treatment for 48 h in vitro, with LC50 values of 13.4±1.8, 11.7±2.5, 13.7±2.4 and 13.31.1 mg.L-1, respectively, which were obviously superior to fosthiazate （49.1±2.8 mg.L-1） and avermectin （26.6±2.3 mg.L-1）. Compound 23. can effectively control the citrus nema- tode disease caused by T. semipenetruns at 200 mg.L-1 in vivo with （68±3）% inhibitory effect, which was even better than that of avermectin （（63±2）%）. The CoMFA and CoMSIA models of three-dimensional quantitative structure-activity relationships （3D-QSARs） were established. The compound 33 was designed based on the 3D-QSAR models with more vigorous nematicidal activities in vitro （LC50：9.8±1.4 mg.L-1） and in vivo （（70±5）%）. These results demonstrated that compound 33 can be considered as a potential nematicide.
基金financially supported by the National Basic Research Program of China (2013CB127501)the National Key Research and Development Program of China (2016YFD0201003)the National Natural Science Foundation of China (31272021, 31571987)
文摘Streptomyces rubrogriseus HDZ-9-47,isolated from eggs of Meloidogyne spp.,was evaluated as a potential biocontrol agent of Meloidogyne incognita under in vitro and protective field.Microscopic observations showed that HDZ-9-47 parasitized eggs of M.incognita within 7 days.In vitro,the culture filtrate of HDZ-9-47 caused 97.0%mortality of second-stage juveniles（J2s）of M.incognita and inhibited more than 50%egg hatching.In the field,compared with the control,the rootknot index and J2s density in the treatment of drench the broth contained 1012 HDZ-9-47 spores were respectively reduced by 51.1 and 80.7%at 90 days post transplantation,which were better than that in other application doses and methods.In addition,reduction rates of root-knot index and J2s density of the treatment of combined application of HDZ-9-47 with biofumigation was 87.1 and 91.0%,respectively,better than either of HDZ-9-47 or biofumigation used alone or fosthiazate treatment.And tomato yield also increased by 16.1%.Together,our results suggest that HDZ-9-47 could be an effective biocontrol agent of M.incognita,and that application of HDZ-9-47 combined with cabbage residue biofumigation was a promising and sustainable option for M.incognita control.
基金financially supported by grants from the National Key Research and Development Program (2018YFD0201202 & 2017YFD0201102)the National Natural Science Foundation of China (31571986)
文摘The root-knot nematode Meloidogyne graminicola is considered one of the most devastating pests in rice-producing areas,and nematicides are neither ecofriendly nor cost effective.More acceptable biological agents are required for controlling this destructive pathogen.In this study,the biocontrol potential of Aspergillus welwitschiae AW2017 was investigated in laboratory and greenhouse experiments.The in vitro ovicidal and larvicidal activities of A.welwitschiae metabolites were tested on M.graminicola in laboratory experiments.The effect of A.welwitschiae on the attraction of M.graminicola to rice and the infection of rice by M.graminicola was evaluated in a greenhouse.The bioagent AW2017 displayed good nematicidal potential via its ovicidal and larvicidal action.The best larvicidal activity was observed at a concentration of 5×AW2017,which caused an 86.2%mortality rate at 48 h post inoculation.The highest ovicidal activity was recorded at a concentration of 5×AW2017,which resulted in an approximately 47.3%reduction in egg hatching after 8 d compared to the control.Under greenhouse conditions,the application of A.welwitschiae significantly reduced the root galls and nematodes in rice roots compared to the control.At a concentration of 5×AW2017,juveniles and root galls in rice roots at 14 d post inoculation(dpi)were reduced by 24.5 and 40.5%,respectively.In addition,the attraction of M.graminicola to rice roots was significantly decreased in the AW2017 treatment,and the development of nematodes in the AW2017-treated plants was slightly delayed compared with that in the PDB-treated control plants.The results indicate that A.welwitschiae is a potential biological control agent against M.graminicola in rice.
基金This work was financially supported by the Natural Science Foundation of Shandong Province,China(ZR2017BC053)the Doctoral Research Startup Foundation of Liaocheng University(318051625).
文摘In recent years,the damage caused by soil nematodes has become increasingly serious;however,the varieties and structures of the nematicides available on the market are deficient.Fluopyram,a succinate dehydrogenase inhibitor(SDHI)fungicide developed by Bayer AG in Germany,has been widely used in the prevention and control of soil nematodes due to its high efficiency and novel mechanism of action.In this paper,two series of novel target compounds were designed and synthesized with nematicidal and fungicidal fluopyram as the molecular skeleton in order to introduce sulfide and sulfone substructures.The structures were identified and characterized by 1H nuclear magnetic resonance(NMR),13C NMR,and high-resolution mass spectrometer(HRMS).The bioassays revealed that most of the compounds showed excellent nematicidal activities at 200 lgmL-1 in comparison with fluopyram,while the nematode mortality rate dropped sharply at 100μg·mL-1,except for compounds I-11 and II-6.In terms of fungicidal activity,compound I-9 was discovered to have an excellent inhibitory rate,and a molecular docking simulation was performed that can provide important guidance for the design and exploration of efficient fungicidal lead compounds.
文摘Quantum chemistry methods were performed in order to characterize the chemical reactivity on series of imidazo[1,2-a]pyridinyl-chalcone (IPC). In particular, the B3LYP/6-311G(d) theory level has been used to determine parameters which characterize the global and local reactivity on five molecules of the series. These compounds differ from one to another with the aryl groups. There are: 1-(2-methylimidazo[1,2-a]pyridin-3-yl)-3-phenylprop-2-en-1-one, 3-(4-fluorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-[4-(dimethylamino)phenyl]-1-(2-methylimidazo [1,2-a]pyridin- 3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one, 3-(2,4-dichlorophenyl)-1-(2-methylimidazo [1,2-a]pyridin-3-yl)prop-2-en-1-one. All results lead to finding out that local nucleophilicity and electrophilicity of compounds are not substituent-dependant contrarily to their global nucleophilicity which prove to be more sensitive to the electron-donating character of the substituents. 3-[4-(Dimethylamino) phenyl]-1-(2-methylimidazo[1,2-a]pyridin-3-yl)prop-2-en-1-one was identified as the unique nucleophile compound by global reactivity. Respectively, the carbon atoms C5 and C14 are the prediction sites of electrophilic and nucleophilic attacks in the molecular skeleton of both molecules. Identification of interactions centres on IPC series is of great importance for organic synthesis and medicinal chemistry where the molecular hybridization strategy is very often used to improve biological activities of interesting therapeutic systems.
文摘Experiments were carried out to study the effect of two fungal bioagents along with mustard oil cake and furadan against root knot nematode Meloidogyne incognita infecting tomato under greenhouse condition. Bioagents viz., Paecilomyces lilacinus and Trichoderma viride alone or in combination with mustard cake and furadan promoted plant growth, reduced number of galls/plant, egg masses/root system and eggs/egg mass. The fungal bioagents along with mustard cake and nematicide showed least nematodes reproduction factor as compared to untreated infested soil.
文摘Root-knot nematodes （Meloidogvne spp.） constrain the production of high value vegetable crops, such as tomato, on smallholder farms in Kenya. For several years, control of root-knot nematodes largely depended on the use of synthetic nematicides, most of which have been banned due to their toxicity to humans and the environment. Farmer-participatory trials were established, for two consecutive growing seasons on farmers＇ fields infested with root-knot nematodes （A4eloidogvne javanica and Meloidogyne incognita）, at two sites in central Kenya （Maragua and Kirinyaga districts）, representing two contrasting group of farmers （low-input and high-input）. The trials aimed at evaluating the potential of using biological control agents （BCAs）, i.e. Poehonia ehlamydosporia and Pasteuria penetrans, antagonistic plants （Crotalaria grahamiana and Tagetes minuta）, ＂＇trash burning＂ and chemical control （dazomet 98% = Basamid~ Granular） in the management of root-knot nematodes in tomato nursery beds, and quantify the associated net benefits, compared to an untreated control. Crotalaria grahamiana, ＂trash burning＂ and dazomet, significantly （P 〈 0.05） reduced the number of second-stage juveniles （J2s） of the root-knot nematodes in the soil in nursery beds during the first season at Karigui-ini, but there was no significant （P 〉 0.05） increase in yield after transplanting tomato seedlings from the respective treatment. Similarly, one of the BCAs （P. ehlamydosporia）, was effectively transferred to the field with seedlings from the BCA-treated nursery beds, but there was no significant （P 〉 0.05） increase in yield due to slow proliferation of the BCA, after transplanting. Participatory partial budgets were successfully developed with srnallholder farmers, and proved to be a vital tool in making informed decisions on management options for root-knot nematodes. In general, labour was considered by all farmers as the major input that contributed to the overall additional cost of the different treatments at both sites. This necessitates improvement in efficiency of labour resource use.
文摘Essential oils （EOs） from Rosemary, Rosmarinus officinalis （Lamiaceae）, Orange, Citrus sinensis （Rutaceae）, Lavandula, Lavandula angustifolia （Lamiaceae）, False Yellowhead, Dittrichia viscosa （Asteraceae） and their major components were evaluated against root knot nematode, Meloidogyne incognita and Meloidogynejavanica. Second stage juveniles＇ （J2） paralysis and egg hatch inhibition were studied, while pulverized plant parts were tested for nematodes biological cycle arrest. All EOs paralyzed J2 and M. incognita were found more sensitive than M javanica with the EC50/4 days calculated at 250, 3,650 and 4,260 12g/mL for 1）. viscosa, L. angustifolia and R. officinalis, respectively. Similarly, all EOs inhibited nematodes egg hatch and D. viscosa exhibited the highest inhibition on egg hatch （100% inhibition at 5 μg/mL）. A significant influence of constituent terpenes （limonene, 1,8-cineole, linalool, camphor, L-borneol, caryophyllene oxide, β-eudesmol） dose and exposure time was indicated on egg hatch inhibition （56% to 100% at 500 μg/mL and 1,000 μg/mL）, while only β-eudesmol achieved paralysis of J2 and specifically against M. incognita （EC50/1d = 50μg/mL）. Interestingly, the most active botanical species arresting Meloidogyne spp. biological cycle in soil was C. sinensis （EC50 = 2 mg/g） and the most sensitive nematode species was M. javanica. The larvicidal and egg hatch inhibition activity holds promise towards the optimization of artificial terpene mixtures as novel and effective natural nematicides. Complex interactions of primary compounds and subsequent decomposition derivates compose efficacy profile of soil amendments.
文摘The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.
