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Calling and Mating Behavior of Malacosoma rectifascia Lajonquère 被引量:3
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作者 李咏玲 曹天文 +2 位作者 王瑞 韩福生 张金桐 《Agricultural Science & Technology》 CAS 2010年第1期69-72,共4页
[Objective]The research aimed to study the calling and mating behavior of Malacosoma rectifascia Lajonquère and provide theoretical basis for utilization of sex pheromone to prevent and control M.rectifascia. [Me... [Objective]The research aimed to study the calling and mating behavior of Malacosoma rectifascia Lajonquère and provide theoretical basis for utilization of sex pheromone to prevent and control M.rectifascia. [Method]Through indoor and outdoor observation,effects of M.rectifascia mating behavior occurrence process,calling period,different sex ratio and population density on mating rate were studied. [Result]The sex ratio of M.rectifascia in nature was 1∶1.2,while in lab was 1∶1.8; the calling peak took place from 19:00 to 21:00;different sex ratio and population density had significant effects on mating behavior,and mating rate would be reduced if the population density was higher; both male and female M.rectifascia mate only once throughout their life. [Conclusion]Controlling M.rectifascia with sex pheromone has good application prospects. 展开更多
关键词 Malacosoma rectifascia Lajonquère Sex pheromone BIOLOGY
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Phylogenetic Analysis of the 16S rDNA of a Strain Isolated from Diseased Larva of Anoplophora glabripennis (Motsch.) 被引量:4
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作者 邓彩萍 刘红霞 +2 位作者 闫喜中 武旭霞 骆有庆 《Agricultural Science & Technology》 CAS 2008年第2期67-69,89,共4页
[ Objective] Study on the phylogenetic analysis of the 16S rDNA and insecticidal characteristics of strain BH-1 isolated from diseased larva of Anoplophora glabripennis (Motseh.) [ Method ] The strain was identified... [ Objective] Study on the phylogenetic analysis of the 16S rDNA and insecticidal characteristics of strain BH-1 isolated from diseased larva of Anoplophora glabripennis (Motseh.) [ Method ] The strain was identified by routine method and inoculated onto healthy Anoplophora glabripennis (Motseh.) for observing insecticidal effect, further 16S DNA was amplified by the specific primers for sequencing and homology analysis. [ Result] The mortality of second instar ofAnoplophora glabripennis( Motseh. ) reached 72.7% 8 d after 10^10cfu/ml BH-1 was inoculated. The homology of 16S DNA sequences between BH-1 and Serratia marcescens accessed in GenBank reached 99.5%. Combined with the results of routine identification, BH-1 was identified as S. marcescens. [Conclusion] BH-1 could be used for biological control ofAnoplophora glabripennis (Motsch.). 展开更多
关键词 Anoplophora glabripennis Motseh. Serratia marcescens 16S rDNA PHYLOGENY
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Reproduction and biological characteristic of Chouioia cunea 被引量:4
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作者 田秀玲 王洪魁 姜凤英 《Journal of Forestry Research》 SCIE CAS CSCD 2002年第4期331-333,338,共3页
Chouioia cunea Yang is a natural enemy for many kinds of crop and forest pests, particularly for Hyphantria cunea Drary, which is an international quarantine pest. The experiment of rearing Chouioia cunea with Tussah ... Chouioia cunea Yang is a natural enemy for many kinds of crop and forest pests, particularly for Hyphantria cunea Drary, which is an international quarantine pest. The experiment of rearing Chouioia cunea with Tussah (Silkworm) pupa were carried out by 搕hree-cut method?and inoculating method. The results showed that three-cut method is effective way for breed-ing Chouioia cunea, with a parasitical rate of 95%. The biological characteristics and the life cycle of Chouioia cunea were ob-served and described and more hosts of Chouioia cunea were found. 揟hree-cut method?as a new technique of rearing Chouioia cunea has been put into practice. 展开更多
关键词 Chouioia cunea Rearing method Pest control Hyphantria cunea
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The Nucleosides Contents and Their Variation in Natural Cordyceps sinensis and Cultured Cordyceps Mycelia 被引量:15
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作者 李绍平 李萍 +3 位作者 季晖 朱荃 董婷霞 詹华强 《Journal of Chinese Pharmaceutical Sciences》 CAS 2001年第4期175-179,共5页
Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleos... Aim: To compare the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia, and to study the effect of humidity and heat on the content of nucleosides. Methods: The contents of nucleosides were determined by using high performance capillary electrophoresis (HPCE). Beckman P/ACE System 5010 apparatus equipped with a UV detector and a Beckman untreated fused-silica capillary (57 cm 75 mm, 50 cm effective length) was used. Before sample injection, the capillary was rinsed with 1 molL-1 sodium hydroxide solution and running buffer for 5 min, respectively. A voltage of 20 kV was applied for the separation. Pressure injection was 586 kPa for 6 seconds, and the wavelength of detector was 254 nm. The running time was 20 min at 20 oC. The effect of humidity and heat on the contents of nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia was observed for 1, 3, 5 and 10 days at temperature 40 oC, and relative humidity 75%. Results: The content of nucleosides from natural Cordyceps sinensis was higher than that from cultured Cordyceps mycelia. But the contents of nucleosides from freshly collected natural Cordyceps sinensis were very low, even below the limit of quantitation. The contents of nucleosides from natural Cordyceps sinensis were significantly increased by humidity and heat, but this phenomenon was not observed in cultured Cordyceps mycelia. Conclusion: There are differences between the nucleosides from natural Cordyceps sinensis and cultured Cordyceps mycelia. The nucleosides in natural Cordyceps sinensis may be derived from the degradation of nucleic acids. This implies that adenosine being used for the quality control of natural Cordyceps sinensis may have to be reconsidered. 展开更多
关键词 CORDYCEPS NUCLEOSIDES ADENOSINE GUANOSINE URIDINE
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天虫
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作者 自在天 《中学生(高中作文版)》 2010年第12期45-49,共5页
抽痛突如其来,苏随呻吟一声,从梦中惊醒,右掌心突突跳动着,每一次跳动都像针扎刀割,撕扯着他的肌肤,苏随捏着掌心不敢动弹。
关键词 小说 文学作品 现代文学 《天虫》
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Test Bench for the Mechanical Distribution of Predators to Control Insect Pests 被引量:4
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作者 M. Khelifi F. Pare M. Aider 《Journal of Environmental Science and Engineering》 2011年第11期1445-1453,共9页
In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle (CPB) succeed in developing resistance to most of the reg... In agriculture, chemical insecticides are widely used to protect crops from insect pests. Over a period of years, some insects such as Colorado potato beetle (CPB) succeed in developing resistance to most of the registered chemical insecticides. Consequently, heavy applications of chemical insecticides to control this pest become ineffective on a long-term basis and can lead to serious health and environmental problems. The use of natural enemies to control CPB is an interesting alternative to chemical means However, hand release of predators is not feasible on a large scale in the field. The main objective of this research study was to design and build a test bench to investigate the technical feasibility of mechanically releasing predators. The test bench consisted of a vertical chain conveyor mounted on two vertical shafts driven by an electric motor. Since the predators are small and fragile, they were placed in a specially designed container to preserve their physical integrity. Trials using this test bench showed that a carrier material was required, because most of the predators remained inside the container. The success of this mass predator release system will be highly valuable for the biological control of insect pests in many crops. 展开更多
关键词 Insect pests chemical insecticides biological control natural enemies mass release mechanical distributor
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Development, manufacture and application of Beta-Cypermethrin aqueous capsule suspension
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作者 郎子建 苏元吉 +1 位作者 王志英 陈立平 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期218-222,共5页
The optimal formula of Beta-Cypermethrin aqueous capsule suspension was screened out through the experiment, preparation and manufacture of basic formulas, which has no sedimentation, suspended drops of oil, peels and... The optimal formula of Beta-Cypermethrin aqueous capsule suspension was screened out through the experiment, preparation and manufacture of basic formulas, which has no sedimentation, suspended drops of oil, peels and agglomerating and the diameter of capsule is in range of 10-30 靘, conformed to the technical requirement. The aftereffect of the 3.3% Beta-Cypermethrin aqueous capsule suspension which was manufactured according to the optimal formula was up more than 25 days. The experiments on controlling the larvae of Dendrolinmus superans Butler and the adults of Xylotrechus rusticus L were carried out with different concentrations of this chemical. The death rate reached 80% when 250 times solution of the chemical was sprayed on stem to control the larvae of D. superans. For control of the adults of X. rusticus, 200, 400 and 600 times solution of the chemical were applied and their control effects (death rate) reached 85.23%, 74.21% and 66.59% respec-tively. Two kinds of solution (200 times and 300 times) of the chemical were used to control the larvae of D. superans in large area, and the control effect for both concentrations was over 90%. 展开更多
关键词 Aqueous capsule suspension Cypermethrin-capsule Pest control Dendrolinmus superans Xylotrechus rusticus.
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Contribution to the Bio-ecological Study of Date Palm Entomofauna in the Region of Saoura (South Algeria)
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作者 Ali Boulanouar Mohammed Anouar Khelil +1 位作者 Ahmed Makhloufi Larbi Benlarbi 《Journal of Life Sciences》 2014年第6期496-503,共8页
Saoura region is situated in the south west of dactylifera), where the authors note several oases such as: Algeria characterized by a height density of date palm trees (Phoenix Taghit, lgli, Beni Abbes... Despite t... Saoura region is situated in the south west of dactylifera), where the authors note several oases such as: Algeria characterized by a height density of date palm trees (Phoenix Taghit, lgli, Beni Abbes... Despite this high density, the production of dates is still insufficient even for the local consumption, this is due to: Increasing salinity of water and soil in the old palm groves, the spread of many fungal diseases, where the most serious is the Bayoud (Fusaruim oxysporum), and finally insect pests, three of them remain the most serious: white scale locally named Semm (Parlatoria blanehardi), Boufaroua (Oligonyehus afrasiaticus), and Doud called dates worm (Ectomyelois ceratoniae). By using different trapping techniques, an entomofauna inventory was realized in the region of Saoura, where 3238 individuals are collected, distributed in 13 orders, 72 families and more than 132 species. The inventory will allow us to classify insects according to their economic importance, determine their life cycle and know their adaptation to date palm. The dynamics of these populations will be studied through the spatial-temporal repartitions. In parallel this study aims to identify the natural enemies (auxiliaries and parasitoids) of date palm pests in order to improve the biological control and this in hopes to ameliorate the production. 展开更多
关键词 Phoenix daetylifera L. Saoura region entomofauna inventory white scale AUXILIARIES parasitoids.
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Studies on the community characteristics of major arthropods in summer maize fields
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作者 YANG Lang CHEN En-hai +1 位作者 HUANG Li-fei JIQNG Jian-jun 《Journal of Agricultural Science and Technology》 2008年第10期26-30,共5页
This study is to integrate pest management (IPM) of maize insect pest. The paper reports the current condition of species diversity of maize field in Nanning, Guangxi Province. All exper/mcntal materials were collec... This study is to integrate pest management (IPM) of maize insect pest. The paper reports the current condition of species diversity of maize field in Nanning, Guangxi Province. All exper/mcntal materials were collected dur/ng the stages of tasseling, blister, milk, maturity and after reaping respectively from 5 plots from April to July, 2007. The Shannon-Wiener index(H), Simpson index(H'), Brillouin index(J), species evenness(E) and richness index (Dmc) were used into analysis of abundance and distribution characteristics of communities and populations of major arthropods in maize fields. Result showed that a total of 19 arthropods, belonged to 10 orders and 18 families, were obtained from maize fields. Of which there are 12 pest insects, 3 natural enemy insects, 2 spiders and 2 middle insects. All of the community diversity indices were the highest in maize fields after reaping. No significant difference was found between other 4 various stages i.t. tasseling, blister, milk and maturity stages. The results of this study will help to carry out the IPM of maize field pest insect. 展开更多
关键词 MAIZE arthropod community DIVERSITY EVENNESS
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The Effectiveness of Coccinellids as Natural Enemies of Aphids in Maize, Beans and Cowpeas Intercrop
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作者 Robert W. Nyukuri Stella C. Kirui +2 位作者 Fred M. E. Wanjala 1 Jared O. Odhiambo Evelyne Cheramgoi 《Journal of Agricultural Science and Technology(A)》 2012年第8期1003-1010,共8页
A field study was conducted in Busia district of Kenya to elucidate the dynamics of ladybirds in mixed stands of maize, beans and cowpeas to determine their efficacy as sole control measures for Aphids. Maize, beans a... A field study was conducted in Busia district of Kenya to elucidate the dynamics of ladybirds in mixed stands of maize, beans and cowpeas to determine their efficacy as sole control measures for Aphids. Maize, beans and cowpeas were intercropped using conventional husbandry practices and the general Coccinellid quantified as follows: Colonies of four Coccinellids, starved for 12 hours to enhance feeding on Aphids were assessed. The effects of weather on the abundance of Coccinellids were also investigated and involved collection of meteorological data from the Busia District Agricultural Office (BDAO) and from Busia Farmers Training Centre (BFTC) and relating them to the abundance and predation values. The predator population was most abundant in the mixed stands of maize and beans (2.33 predators/30 Aphids) as compared to their occurrence in pure stands of cowpeas (0.85 predators/30 Aphids). The genus Cheilomenes spp. was the most ubiquitous predator with a mean of 4.00 individuals/30 Aphids while Hippodamia variegata was the least abundant predator species with a mean of 0.92 individuals/30 Aphids in all the agro-ecosystems. The larvae of Hippodamia variegata were the most bio-efficient, consuming 32.44 Aphids while their adults were the least bio-efficient, consuming 4.22 individuals for a period of 12 hours. The Coccinellids consumed more Aphids at higher aphid densities (24.05 Aphids) than at lower aphid densities (9.44 Aphids) over the same period of time. Rainfall and relative humidity had significant (F = 3.675; P 〈 0.05) effects on the abundance of Coccinellids. Temperature had significant (F = 3.58; P 〈 0.05) effect on the abundance of Coccinellids though at a lower level. Rainfall (r = -0.162) and relative humidity (r = - 0.084) were both inversely correlated with the abundance of Coccinellids. On the other hand, temperature was positively correlated (r = 0.159) with the prevalence of Coccinellids indicating that warmer and drier conditions favoured their multiplication. 展开更多
关键词 Efficacy COCCINELLIDS APHIDS natural enemies ecological factors crops.
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BIOLOGICAL CONTROL OF COFFEE STEM BORERS, XYLOTRECHUS QUARDRIPES AND ACALOLEPTA CERVINUS, BY BEAUVERIA BASSIANA PREPARATION 被引量:3
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作者 魏佳宁 况荣平 《Entomologia Sinica》 CSCD 2002年第2期43-50,共8页
The use of Beauveria bassiana proparations for control of coffee stem borers, Xylotrechus quardripes Chevr. and Acalolepta cervinus (Hope), as tested in the laboratory and field conditions. The results ... The use of Beauveria bassiana proparations for control of coffee stem borers, Xylotrechus quardripes Chevr. and Acalolepta cervinus (Hope), as tested in the laboratory and field conditions. The results show that each instar of coffee stem borers could be infected and killed successfully when being inoculated or contacted with B. bassiana . The control efficacy under indoor cultivation conditions exceeded 90% within 15 days. Jamming drilled hole with fungal mud resulted in the accumulative mortality and corrected mortality of >90% within 20 days. In the field, three methods, jamming drilled holes with bamboo sticker, bamboo sticker with fungal mud, and fungal mud only, were employed, and each led to the control effect of > 90% within 20 days. However, spraying suspensions and dusting powder of B. bassiana was insignificant. The yield of fresh coffee fruits in biological control area was 125 7?kg/0 067?ha greater than that of control area when being harvested in February. Compared the cost of microbial control with that of chemical control, B. bassiana proved to be a profitable, effective, and safe biocontrol agent against coffee stem borer. 展开更多
关键词 Beauveria bassiana biological control coffee stem borers Xylotrechus quardripes Acalolepta cervinus
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Effects of transgenic Cry1A+CpTI cotton and Cry1Ac toxin on the parasitoid, Campoketis chlorideae (Hymenoptera:Ichneumonidae) 被引量:7
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作者 XIAO-XIALIU CHANG-GUISUN QING-WENZHANG 《Insect Science》 SCIE CAS CSCD 2005年第2期101-107,共7页
The effect of transgenic double genes, Cry1A + CpTI cotton and Cry1Ac toxinon the parasitoid, Campoketis chlorideae Uchida of cotton bollworm, Helicoverpa armigera (Huebner),was investigated in the laboratory. Helicov... The effect of transgenic double genes, Cry1A + CpTI cotton and Cry1Ac toxinon the parasitoid, Campoketis chlorideae Uchida of cotton bollworm, Helicoverpa armigera (Huebner),was investigated in the laboratory. Helicoverpa armigera larvae when in the first, second and thirdinstar could not survive if fed on transgenic cotton leaves. Consequently, C. chlorideae larvaecould not complete their development if parasitizing on such hosts. After H. armigera larvae werereared on transgenic or traditional cotton leaves for 12-48 hours, they were parasitized by C.chlorideae females. Parasitized larvae continued to feed on transgenic or traditional cotton for12-48 h. The present results showed that the body weight of larvae of the parasitoids weresignificantly reduced when parasitized hosts fed on transgenic cotton leaves compared to those fedon traditional cotton. Duration of egg and larvae stage were significantly prolonged, pupal andadult weight of C. chloridae was decreased when the host larvae fed on transgenic cotton leaveslonger than 48 h. The development duration of C. chlorideae pupae on the hosts fed on transgeniccotton leaves in each treatment was not significantly different from those of controls. Thelongevity of parasitoid females and males fed with a solution containing Cry1Ac toxin was notsignificantly different with that of the control. 展开更多
关键词 Cry1A + CpTI genes helicoverpa armigera transgenic cotton natural enemy campoketis chlorideae uchida
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Emerging infectious diseases associated with bat viruses 被引量:10
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作者 SHI ZhengLi 《Science China(Life Sciences)》 SCIE CAS 2013年第8期678-682,共5页
Bats play important roles as pollen disseminators and pest predators.However,recent interest has focused on their role as natural reservoirs of pathogens associated with emerging infectious diseases.Prior to the outbr... Bats play important roles as pollen disseminators and pest predators.However,recent interest has focused on their role as natural reservoirs of pathogens associated with emerging infectious diseases.Prior to the outbreak of severe acute respiratory syndrome(SARS),about 60 bat virus species had been reported.The number of identified bat viruses has dramatically increased since the initial SARS outbreak,and most are putative novel virus species or genotypes.Serious infectious diseases caused by previously identified bat viruses continue to emerge throughout in Asia,Australia,Africa and America.Intriguingly,bats infected by these different viruses seldom display clinical symptoms of illness.The pathogenesis and potential threat of bat-borne viruses to public health remains largely unknown.This review provides a brief overview of bat viruses associated with emerging human infectious diseases. 展开更多
关键词 emerging infectious disease bat virus natural reservoirs
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Effects of selected insecticides on Diadegma semiclausum(Hymenoptera: Ichneumonidae) and Oomyzus sokolowskii (Hymenoptera: Eulophidae), parasitoids of Plutella xylostella (Lepidoptera: Plutellidae) 被引量:4
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作者 MUHAMMADHASEEB HIROSHIAMANO TONG-XIANLIU 《Insect Science》 SCIE CAS CSCD 2005年第3期163-170,共8页
Field doses of six selected insecticides were tested against the immature(pupae) and mature (adult) stages of Diadegma semiclausum (Hellen) and Oomyzus sokolowskii(Kurdjumov), parasitoids of the diamondback moth, Plut... Field doses of six selected insecticides were tested against the immature(pupae) and mature (adult) stages of Diadegma semiclausum (Hellen) and Oomyzus sokolowskii(Kurdjumov), parasitoids of the diamondback moth, Plutella xylostella (L.). Effects of contacttoxicity (direct spraying) of the six insecticides on emergence of parasitoids were found negligibleon both species except permethrin which caused 37.5% mortality. All adults of both parasitoidspecies died 24 hours after exposure to chlorfenapyr, emamectin benzoate and permethrin. Incontrast, the three insect growth regulators (IGRs), chlorfluazuron, flufenoxuron and teflubenzuron,were found harmless to both species, and adult mortality of both parasitoid species was 0—16.7%.However, parasitism by the females of both parasitoid species was severely impaired when the femaleswere offered the three IGR diluted solutions for 24 hours. Effects of oral toxicities of the IGRson longevity of both parasitoids after 12 hours exposure were found to be significantly differentbetween males and females. Compatibility of tested insecticides with D. semiclausum and O.sokolowskii and integration of compatible insecticides with these parasitoids in integrated pestmanagement programs of crucifers are discussed. 展开更多
关键词 compatibility beneficial species biocontrol IPM pesticidal effects toxicity
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Effects of crop species richness on pest-natural enemy systems based on an experimental model system using a microlandscape 被引量:2
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作者 ZHAO ZiHua SHI PeiJian +2 位作者 MEN XingYuan OUYANG Fang GE Feng 《Science China(Life Sciences)》 SCIE CAS 2013年第8期758-766,共9页
The relationship between crop richness and predator-prey interactions as they relate to pest-natural enemy systems is a very important topic in ecology and greatly affects biological control services.The effects of cr... The relationship between crop richness and predator-prey interactions as they relate to pest-natural enemy systems is a very important topic in ecology and greatly affects biological control services.The effects of crop arrangement on predator-prey interactions have received much attention as the basis for pest population management.To explore the internal mechanisms and factors driving the relationship between crop richness and pest population management,we designed an experimental model system of a microlandscape that included 50 plots and five treatments.Each treatment had 10 repetitions in each year from 2007 to 2010.The results showed that the biomass of pests and their natural enemies increased with increasing crop biomass and decreased with decreasing crop biomass;however,the effects of plant biomass on the pest and natural enemy biomass were not significant.The relationship between adjacent trophic levels was significant(such as pests and their natural enemies or crops and pests),whereas non-adjacent trophic levels(crops and natural enemies) did not significantly interact with each other.The ratio of natural enemy/pest biomass was the highest in the areas of four crop species that had the best biological control service.Having either low or high crop species richness did not enhance the pest population management service and lead to loss of biological control.Although the resource concentration hypothesis was not well supported by our results,high crop species richness could suppress the pest population,indicating that crop species richness could enhance biological control services.These results could be applied in habitat management aimed at biological control,provide the theoretical basis for agricultural landscape design,and also suggest new methods for integrated pest management. 展开更多
关键词 biological control service BIOMASS habitat management microlandscape trophic level
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Cascade effects of crop species richness on the diversity of pest insects and their natural enemies 被引量:6
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作者 SHI PeiJian HUI Cang +6 位作者 MEN XingYuan ZHAO ZiHua OUYANG Fang GE Feng JIN XianShi CAO HaiFeng LI B.Larry 《Science China(Life Sciences)》 SCIE CAS 2014年第7期718-725,共8页
Understanding how plant species richness influences the diversity of herbivorous and predatory/parasitic arthropods is central to community ecology.We explore the effects of crop species richness on the diversity of p... Understanding how plant species richness influences the diversity of herbivorous and predatory/parasitic arthropods is central to community ecology.We explore the effects of crop species richness on the diversity of pest insects and their natural enemies.Using data from a four-year experiment with five levels of crop species richness,we found that crop species richness significantly affected the pest species richness,but there were no significant effects on richness of the pests’natural enemies.In contrast,the species richness of pest insects significantly affected their natural enemies.These findings suggest a cascade effect where trophic interactions are strong between adjacent trophic levels,while the interactions between connected but nonadjacent trophic levels are weakened by the intermediate trophic level.High crop species richness resulted in a more stable arthropod community compared with communities in monoculture crops.Our results highlight the complicated cross-trophic interactions and the crucial role of crop diversity in the food webs of agro-ecosystems. 展开更多
关键词 trophic level stability generalized additive model MONOCULTURE POLYCULTURE
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Light carbon isotope events of foraminifera attributed to methane release from gas hydrates on the continental slope, northeastern South China Sea 被引量:4
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作者 ZHUANG Chang CHEN Fang +4 位作者 CHENG SiHai LU HongFeng WU Cong CAO Jun DUAN Xiao 《Science China Earth Sciences》 SCIE EI CAS CSCD 2016年第10期1981-1995,共15页
In 2013, the China Geological Survey and Guangzhou Marine Geological Survey conducted the second Chinese gas hydrate expedition in the northern South China Sea (SCS) and successfully obtained visible gas hydrate sam... In 2013, the China Geological Survey and Guangzhou Marine Geological Survey conducted the second Chinese gas hydrate expedition in the northern South China Sea (SCS) and successfully obtained visible gas hydrate samples. Five of the thirteen drilling sites were cored for further research. In this work, Site GMGS2-08 is selected for the stable isotopic analy- sis of foraminifera present in the boreholes in order to reveal the carbon isotopic characteristics of the foraminifera and their response to methane release in the gas hydrate geological system. Our results show that the methane content at Site GMGS2-08 is extremely high, with headspace methane concentrations up to 39300 μmol L^-1. The hydrocarbon δ^13C values, ranging from -69.4%o to -72.3‰ PDB, distinctly indicate biogenic generation. Based on the δD analytical results (-183‰ to -185‰ SMOW), headspace methane is further discriminated to be microbial gas, derived from CO2 reduction. By isotopic measurement, five light δ^13C events are found in the boreholes from Site GMGS2-08, with foraminiferal δ^13C values being ap- parently lower than the normal variation range found in the glacial-interglacial cycles of the SCS. The δ^13C values of benthic Uvigerina peregrina are extremely depleted (as low as -15.85‰ PDB), while those of planktonic Globigerinoides ruber reach -5.68‰ PDB. Scanning electron micrograph (SEM) studies show that foraminiferal tests have experienced post-depositional alteration, infilled with authigenic carbonate, and the diagenetic mineralization is unlikely to be related to the burial depths. The correlation calculation suggests that the anaerobic oxidation of organic matter has only weak influences on the δ^13C com- position of benthic foraminifera. This means that the anomalous δ^13C depletions are predominantly attributed to the overprint- ing of secondary carbonates derived from the anaerobic oxidation of methane (AOM). Furthermore, the negative δ^13C anoma- lies, coupled with the positive δ^18O anomalies observed at Site GMGS2-08, are most likely the critical pieces of evidence for gas hydrate dissociation in the geological history of the study area. 展开更多
关键词 Gas hydrates Carbon isotopes FORAMINIFERA South China Sea Taixinan Basin
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Differential immune responses of Monochamus alternatus against symbiotic and entomopathogenic fungi
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作者 Wei Zhang Jie Meng +8 位作者 Jing Ning Peijun Qin Jiao Zhou Zhen Zou Yanhong Wang Hong Jiang Faheem Ahmad Lilin Zha Jianghua Sun 《Science China(Life Sciences)》 SCIE CAS CSCD 2017年第8期902-910,共9页
Monochamus alternatus, the main vector beetles of invasive pinewood nematode, has established a symbiotic relationship with a native ectotrophic fungal symbiont, Sporothrix sp. 1, in China. The immune response ofM. al... Monochamus alternatus, the main vector beetles of invasive pinewood nematode, has established a symbiotic relationship with a native ectotrophic fungal symbiont, Sporothrix sp. 1, in China. The immune response ofM. alternatus to S. sp. 1 in the coexistence of beetles and fungi is, however, unknown. Here, we report that immune responses ofM. alternatus pupae to infection caused by ectotrophic symbiotic fungus S. sp. 1 and entomopathogenic fungus Beauveria bassiana differ significantly. The S. sp. 1 did not kill the beetles while B. bassiana killed all upon injection. The transcriptome results showed that the numbers of differentially expressed genes in M. aIternatus infected with S. sp. 1 were 2-fold less than those infected with B. bassiana at 48 hours post infection. It was noticed that Toll and IMD pathways played a leading role in the beetle's immune system when infected by symbiotic fungus, but upon infection by entomopathogenic fimgus, only the Toll pathway gets triggered actively. Furthermore, the beetles could tolerate the infection of symbiotic fungi by retracing their Toll and IMD pathways at 48 h. This study provided a comprehensive sequence resource ofM. alternatus transcriptome for further study of the immune interactions between host and associated fungi. 展开更多
关键词 Monochamus alternatus symbiotic fungus Beauveria bassiana RNA-SEQ immune signaling pathway
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