A quantitative survey of rice planthoppers in paddy fields is important to assess the population density and make forecasting decisions. Manual rice planthopper survey methods in paddy fields are time-consuming, fatig...A quantitative survey of rice planthoppers in paddy fields is important to assess the population density and make forecasting decisions. Manual rice planthopper survey methods in paddy fields are time-consuming, fatiguing and tedious. This paper describes a handheld device for easily capturing planthopper images on rice stems and an automatic method for counting rice planthoppers based on image processing. The handheld device consists of a digital camera with WiFi, a smartphone and an extrendable pole. The surveyor can use the smartphone to control the camera, which is fixed on the front of the pole by WiFi, and to photograph planthoppers on rice stems. For the counting of planthoppers on rice stems, we adopt three layers of detection that involve the following:(a) the first layer of detection is an AdaBoost classifier based on Haar features;(b) the second layer of detection is a support vector machine(SVM) classifier based on histogram of oriented gradient(HOG) features;(c) the third layer of detection is the threshold judgment of the three features. We use this method to detect and count whiteback planthoppers(Sogatella furcifera) on rice plant images and achieve an 85.2% detection rate and a 9.6% false detection rate. The method is easy, rapid and accurate for the assessment of the population density of rice planthoppers in paddy fields.展开更多
The fecundity and spawning locations of rice planthoppers in several rice varieties were surveyed in the test. The results showed that spawning behavior of rice planthoppers obeyed obvious niche distribution; rice pla...The fecundity and spawning locations of rice planthoppers in several rice varieties were surveyed in the test. The results showed that spawning behavior of rice planthoppers obeyed obvious niche distribution; rice planthopper preferred to lay eggs in the leaf sheath with spawning mark distance more than 20 cm, while they liked to lay eggs in the leaves with spawning mark distance of 10 - 20 cm. The average fecundity in leaf sheaths was obviously higher than that in leaves, indicating that leaf sheaths were more suitable for spawning of rice planthoppers than leaves.展开更多
Egg parasitoids,Anagrus spp.and Oligositaspp.have been found to be important biologi-cal agents in suppressing rice planthoppers inAsian countries.However,most of these stud-ies have been confined to conditions within...Egg parasitoids,Anagrus spp.and Oligositaspp.have been found to be important biologi-cal agents in suppressing rice planthoppers inAsian countries.However,most of these stud-ies have been confined to conditions within ricefields.In this study,field surveys were madeto study the floral and faunal diversity in vari-ous habitats surrounding rice fields.The riceand grass(Echinochloa spp.)plants were in-展开更多
The rice planthopper,including brown planthopper(Nilaparvata hugens Stal)and white—backed planthopper(Sogata furcifera Hor-vath),is one kind of tropical pests.They im-migrate with the southeast monsoon from low—lati...The rice planthopper,including brown planthopper(Nilaparvata hugens Stal)and white—backed planthopper(Sogata furcifera Hor-vath),is one kind of tropical pests.They im-migrate with the southeast monsoon from low—latitude area into China at March of April.The global climatic anomaly especially the ElNi (?)o event and the Southern Oscillation(theENSO event)directly influence the rice plan-展开更多
In recent years,it has been demonstrated that thelow-level jet streams(LLJs)developed in thesouth of the Meiyu(Baiu)front play a critical role inthe overseas migrations of the planthoppers intoJapan and Korea. However...In recent years,it has been demonstrated that thelow-level jet streams(LLJs)developed in thesouth of the Meiyu(Baiu)front play a critical role inthe overseas migrations of the planthoppers intoJapan and Korea. However, the involement of theLLJs during the process of sequential displacements展开更多
Wolbachia and Cardinium are widely distributed and are considered important for their ability to disturb reproduction and affect other fitness-related traits of their hosts. By using multilocus sequence typing (MLST...Wolbachia and Cardinium are widely distributed and are considered important for their ability to disturb reproduction and affect other fitness-related traits of their hosts. By using multilocus sequence typing (MLST), RFLP (restriction fragment length poly- morphism) and 16S ribosomal DNA gene sequencing methods, we extensively surveyed Wolbachia and Cardinium infection status of four predominant rice planthoppers and one kind of leafhopper in different rice fields. The results demonstrated that Sogatellafurcifera (Horv^ith) and Laodelphax striatellus (Fallrn) were infected with the same Wolbachia strain (wStri), while Nilaparvata lugens (St^l) and its closely related species Nilaparvata muiri China were infected with two phylogeneticlly distant strains, wLug and wMui, respectively. Three new Wolbachia strains (provisionally named wMfasl, wMfas2 and wMfas3) were detected in the leafhopper Macrostelesfascifrons (Stal). Only S. furcifera was co-infected with Cardinium, which indicated that the distribution of Cardinium in these rice planthop- pers was narrower than that of Wolbachia. Unambiguous intragenic recombination events among these Wolbachia strains and incongruent phylogenetic relationships show that the connections between different Wolbachia strains and hosts were more complex than we expected. These results suggest that horizontal transmission and host associated special- ization are two factors affecting Wolbachia and Cardinium infections among planthoppers and their related species.展开更多
An interspecific hybrid line pf9279 was obtained by proto-plast fusion between 02428(japonica, with a wide com-patibility gene) and CNW240 (O. officinalis, fromMalaysia) at CNRRI in 1992. Possible introgression of
Rice ragged stunt virus(RRSV) is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein(CP) gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21(...Rice ragged stunt virus(RRSV) is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein(CP) gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21(DE3) using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody(MAb) against RRSV was obtained by fusing mouse myeloma cells(Sp 2/0) with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay(ACP-ELISA), a dot enzyme-linked immunosorbent assay(dot-ELISA), and immunocapture-RT-PCR(IC-RT-PCR) assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1:40 960, 1:1 280 and 1:655 360(w/v, g mL-1), respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1:12 800 and 1:1 600(an individual planthopper μL-1), respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.展开更多
The brown planthopper,Nilaparata lugens(Stl)(BPH)is one of the most important insect pests of rice in China and other east-southern Asian countries.Untilization of rice resistance varieties is one of the most econnomi...The brown planthopper,Nilaparata lugens(Stl)(BPH)is one of the most important insect pests of rice in China and other east-southern Asian countries.Untilization of rice resistance varieties is one of the most econnomic and effective ways for展开更多
Japanese japonica rice commonlyprovides with an ovicidal resistanceagainst the whitebacked planthopper(WBPH). Similarly, ovicidal activi-ty was also found to play a significantrole in a stable field resistance toWBPH ...Japanese japonica rice commonlyprovides with an ovicidal resistanceagainst the whitebacked planthopper(WBPH). Similarly, ovicidal activi-ty was also found to play a significantrole in a stable field resistance toWBPH in some Chinese japonicarice. Rice varieties with ovicidal re-展开更多
[Objective]The paper was to study the relationship between rice leaf roller,rice planthopper and spider and their ecological regulation ability in the field.[Method]The population dynamics of rice leaf roller,rice pla...[Objective]The paper was to study the relationship between rice leaf roller,rice planthopper and spider and their ecological regulation ability in the field.[Method]The population dynamics of rice leaf roller,rice planthopper and spider at three different sowing and transplanting periods of single cropping hybrid rice in the treatment area with combination of 3 drug formulations and untreated area were monitored.[Result]There were significant or extremely significant positive correlations among rice leaf roller,rice planthopper and spider in single cropping hybrid rice.However,with the delay of planting and transplanting period,the population fluctuation crest of rice leaf roller and rice planthopper decreased,but the intensity increased with the advance of time,and the natural ecological regulation ability was relatively improved.[Conclusion]The sowing period of single cropping hybrid rice is delayed 5-10 d compared with conventional rice,that is,sowing in late May and early June.The seedling age of 20-30 d is beneficial not only to reduce the initial population quantity of rice leaf roller and rice planthopper in the field,but also to increase the population quantity of spiders.展开更多
To safely and sustainably utilize genetic breeding techniques for crop production, greater understanding of the potential effects of genetically modified herbicide-tolerant(GMHT) crops on the ecological functions of...To safely and sustainably utilize genetic breeding techniques for crop production, greater understanding of the potential effects of genetically modified herbicide-tolerant(GMHT) crops on the ecological functions of predators is required. In the laboratory, we examined the functional and numerical responses of Cyrtorhinus lividipennis Reuter to eggs of brown planthopper(BPH), Nilaparvata lugens(St?l), which were reared on GMHT rice Bar68-1; the untransformed parental cultivar, D68; or a BPH-susceptive rice variety, Taichung Native 1. All stages of nymphs and female adult of C. lividipennis, either on GMHT rice or control plants, exhibited typical type II functional responses when fed on BPH eggs; the attacking rate and handling time of C. lividipennis on GMHT rice Bar68-1 was not significantly different from that on D68. The numerical responses of C. lividipennis on GMHT rice or controls fit Beddington's model; there were no significant differences in the parameters of numerical responses between GMHT rice Bar68-1 and D68. The results indicated that the functional and numerical responses of C. lividipennis to BPH eggs are not affected by GMHT rice Bar68-1.展开更多
Sogatella furcifera (Hovarth) is a major rice pest with sexual dimorphism. The objective of the current research was to monitor differentially cytosine methylation at CCGG sequences in male and female adults of S. f...Sogatella furcifera (Hovarth) is a major rice pest with sexual dimorphism. The objective of the current research was to monitor differentially cytosine methylation at CCGG sequences in male and female adults of S. furcifera to determine the association between gene methylation and sexual phenotypes using methylation-sensitive representa- tional difference analysis. After the second subtractive hybridization, four differentially methylated DNA bands were obtained and sequenced. Ten different fragments were found. One fragment from the positive hybridization was 120 bp, and highly similar to the tram- track genes from Nasonia vitripennis. Another fragment from the reverse hybridization was 414 bp, and homologous to the 28S rRNA gene of S. furcifera with a similarity rate as high as 99%. We also discussed how DNA methylation of tramtrack and 28S rRNA genes produced effects on sexual differentiation and development. These results provide potential evidence that DNA methylation of some genes may be related to sexual phenotype variations in S.furcifera and will facilitate future studies on the epigenetic mechanisms of insect sexual dimorphism.展开更多
基金the National Natural Science Foundation of China (31071678)the National High Technology Research and Development Program of China (863 Program, 2013AA102402)Zhejiang Provincial Natural Science Foundation of China (LY13C140009)
文摘A quantitative survey of rice planthoppers in paddy fields is important to assess the population density and make forecasting decisions. Manual rice planthopper survey methods in paddy fields are time-consuming, fatiguing and tedious. This paper describes a handheld device for easily capturing planthopper images on rice stems and an automatic method for counting rice planthoppers based on image processing. The handheld device consists of a digital camera with WiFi, a smartphone and an extrendable pole. The surveyor can use the smartphone to control the camera, which is fixed on the front of the pole by WiFi, and to photograph planthoppers on rice stems. For the counting of planthoppers on rice stems, we adopt three layers of detection that involve the following:(a) the first layer of detection is an AdaBoost classifier based on Haar features;(b) the second layer of detection is a support vector machine(SVM) classifier based on histogram of oriented gradient(HOG) features;(c) the third layer of detection is the threshold judgment of the three features. We use this method to detect and count whiteback planthoppers(Sogatella furcifera) on rice plant images and achieve an 85.2% detection rate and a 9.6% false detection rate. The method is easy, rapid and accurate for the assessment of the population density of rice planthoppers in paddy fields.
基金Supported by National "12th Five-Year Plan" Key Technology R&D Program(2012BAD19B03)
文摘The fecundity and spawning locations of rice planthoppers in several rice varieties were surveyed in the test. The results showed that spawning behavior of rice planthoppers obeyed obvious niche distribution; rice planthopper preferred to lay eggs in the leaf sheath with spawning mark distance more than 20 cm, while they liked to lay eggs in the leaves with spawning mark distance of 10 - 20 cm. The average fecundity in leaf sheaths was obviously higher than that in leaves, indicating that leaf sheaths were more suitable for spawning of rice planthoppers than leaves.
文摘Egg parasitoids,Anagrus spp.and Oligositaspp.have been found to be important biologi-cal agents in suppressing rice planthoppers inAsian countries.However,most of these stud-ies have been confined to conditions within ricefields.In this study,field surveys were madeto study the floral and faunal diversity in vari-ous habitats surrounding rice fields.The riceand grass(Echinochloa spp.)plants were in-
文摘The rice planthopper,including brown planthopper(Nilaparvata hugens Stal)and white—backed planthopper(Sogata furcifera Hor-vath),is one kind of tropical pests.They im-migrate with the southeast monsoon from low—latitude area into China at March of April.The global climatic anomaly especially the ElNi (?)o event and the Southern Oscillation(theENSO event)directly influence the rice plan-
文摘In recent years,it has been demonstrated that thelow-level jet streams(LLJs)developed in thesouth of the Meiyu(Baiu)front play a critical role inthe overseas migrations of the planthoppers intoJapan and Korea. However, the involement of theLLJs during the process of sequential displacements
文摘Wolbachia and Cardinium are widely distributed and are considered important for their ability to disturb reproduction and affect other fitness-related traits of their hosts. By using multilocus sequence typing (MLST), RFLP (restriction fragment length poly- morphism) and 16S ribosomal DNA gene sequencing methods, we extensively surveyed Wolbachia and Cardinium infection status of four predominant rice planthoppers and one kind of leafhopper in different rice fields. The results demonstrated that Sogatellafurcifera (Horv^ith) and Laodelphax striatellus (Fallrn) were infected with the same Wolbachia strain (wStri), while Nilaparvata lugens (St^l) and its closely related species Nilaparvata muiri China were infected with two phylogeneticlly distant strains, wLug and wMui, respectively. Three new Wolbachia strains (provisionally named wMfasl, wMfas2 and wMfas3) were detected in the leafhopper Macrostelesfascifrons (Stal). Only S. furcifera was co-infected with Cardinium, which indicated that the distribution of Cardinium in these rice planthop- pers was narrower than that of Wolbachia. Unambiguous intragenic recombination events among these Wolbachia strains and incongruent phylogenetic relationships show that the connections between different Wolbachia strains and hosts were more complex than we expected. These results suggest that horizontal transmission and host associated special- ization are two factors affecting Wolbachia and Cardinium infections among planthoppers and their related species.
文摘An interspecific hybrid line pf9279 was obtained by proto-plast fusion between 02428(japonica, with a wide com-patibility gene) and CNW240 (O. officinalis, fromMalaysia) at CNRRI in 1992. Possible introgression of
基金supported by the National Basic Research Program of China(2010CB126203)the special fund for Agro-scientific Research in the Public Interest,China(201003031)+1 种基金Earmarked Funds for Modern Agro-industry Technology Research SystemZhejiang Provincial Natural Science Foundation of China(Z3090039)
文摘Rice ragged stunt virus(RRSV) is a serious rice disease in Asia, causing serious yield losses on rice. The capsid protein(CP) gene of the major outer capsid protein of RRSV was expressed in Escherichia coli BL21(DE3) using the pMAL-C2 X expression vector. The recombinant protein was used as the immunogen to immunize BALB/c mice. A hybridoma cell line 8A12 secreting monoclonal antibody(MAb) against RRSV was obtained by fusing mouse myeloma cells(Sp 2/0) with spleen cells from the immunized BALB/c mice. Western blot analysis showed that the MAb 8A12 can specifically react with RRSV CP. Using the MAb, an antigen-coated-plate enzyme-linked immunosorbent assay(ACP-ELISA), a dot enzyme-linked immunosorbent assay(dot-ELISA), and immunocapture-RT-PCR(IC-RT-PCR) assay were developed to detect RRSV. The established ACP-ELISA, dot-blot ELISA and IC-RT-PCR methods could detect RRSV in infected rice tissue crude extracts with dilutions of 1:40 960, 1:1 280 and 1:655 360(w/v, g mL-1), respectively. The ACP-ELISA and dot-blot ELISA methods could detect RRSV in infected insect vector crude extracts with dilutions of 1:12 800 and 1:1 600(an individual planthopper μL-1), respectively. The field survey revealed that Rice ragged stunt disease occurs on rice in Hainan, Yunnan, Guangxi, Sichuan, Guizhou, Fujian, Hunan, Jiangxi and Zhejiang in China.
文摘The brown planthopper,Nilaparata lugens(Stl)(BPH)is one of the most important insect pests of rice in China and other east-southern Asian countries.Untilization of rice resistance varieties is one of the most econnomic and effective ways for
文摘Japanese japonica rice commonlyprovides with an ovicidal resistanceagainst the whitebacked planthopper(WBPH). Similarly, ovicidal activi-ty was also found to play a significantrole in a stable field resistance toWBPH in some Chinese japonicarice. Rice varieties with ovicidal re-
基金Supported by Science and Technology Project of Taizhou City(14NY14)Key Research and De-velopment Program of Zhejiang Province(2016C02050-3-4)
文摘[Objective]The paper was to study the relationship between rice leaf roller,rice planthopper and spider and their ecological regulation ability in the field.[Method]The population dynamics of rice leaf roller,rice planthopper and spider at three different sowing and transplanting periods of single cropping hybrid rice in the treatment area with combination of 3 drug formulations and untreated area were monitored.[Result]There were significant or extremely significant positive correlations among rice leaf roller,rice planthopper and spider in single cropping hybrid rice.However,with the delay of planting and transplanting period,the population fluctuation crest of rice leaf roller and rice planthopper decreased,but the intensity increased with the advance of time,and the natural ecological regulation ability was relatively improved.[Conclusion]The sowing period of single cropping hybrid rice is delayed 5-10 d compared with conventional rice,that is,sowing in late May and early June.The seedling age of 20-30 d is beneficial not only to reduce the initial population quantity of rice leaf roller and rice planthopper in the field,but also to increase the population quantity of spiders.
基金supported by the National Natural Science Foundation of China (31160365 and 31360437)the Special Fund for Agro-Scientific Research in the Public Interest in China (201403031 and 201303017)+2 种基金the Research Funds from Guangxi Academy of Agricultural Sciences, China (2014YP08 and 2014JZ07)the Program for Specially Hired Expert in Guangxi,Chinathe International Science & Technology Cooperation Program of China (2012DFA31220)
文摘To safely and sustainably utilize genetic breeding techniques for crop production, greater understanding of the potential effects of genetically modified herbicide-tolerant(GMHT) crops on the ecological functions of predators is required. In the laboratory, we examined the functional and numerical responses of Cyrtorhinus lividipennis Reuter to eggs of brown planthopper(BPH), Nilaparvata lugens(St?l), which were reared on GMHT rice Bar68-1; the untransformed parental cultivar, D68; or a BPH-susceptive rice variety, Taichung Native 1. All stages of nymphs and female adult of C. lividipennis, either on GMHT rice or control plants, exhibited typical type II functional responses when fed on BPH eggs; the attacking rate and handling time of C. lividipennis on GMHT rice Bar68-1 was not significantly different from that on D68. The numerical responses of C. lividipennis on GMHT rice or controls fit Beddington's model; there were no significant differences in the parameters of numerical responses between GMHT rice Bar68-1 and D68. The results indicated that the functional and numerical responses of C. lividipennis to BPH eggs are not affected by GMHT rice Bar68-1.
基金This research was supported by the National Nat- ural Science Foundation of China (31171844) and Natural Science Foundation of Guangdong Province ($2011010001353). We are very grateful to Dr. Min Zhang and Mrs. Wen-Jing Wu for technical assistance.
文摘Sogatella furcifera (Hovarth) is a major rice pest with sexual dimorphism. The objective of the current research was to monitor differentially cytosine methylation at CCGG sequences in male and female adults of S. furcifera to determine the association between gene methylation and sexual phenotypes using methylation-sensitive representa- tional difference analysis. After the second subtractive hybridization, four differentially methylated DNA bands were obtained and sequenced. Ten different fragments were found. One fragment from the positive hybridization was 120 bp, and highly similar to the tram- track genes from Nasonia vitripennis. Another fragment from the reverse hybridization was 414 bp, and homologous to the 28S rRNA gene of S. furcifera with a similarity rate as high as 99%. We also discussed how DNA methylation of tramtrack and 28S rRNA genes produced effects on sexual differentiation and development. These results provide potential evidence that DNA methylation of some genes may be related to sexual phenotype variations in S.furcifera and will facilitate future studies on the epigenetic mechanisms of insect sexual dimorphism.