Consecutive stresses,such as initial submergence during germination followed by water deficit during the seedling stage,pose significant challenges to direct-seeded rice cultivation.By Linkage disequilibrium analysis,...Consecutive stresses,such as initial submergence during germination followed by water deficit during the seedling stage,pose significant challenges to direct-seeded rice cultivation.By Linkage disequilibrium analysis,Sub1 and Dro1(Δbp:10 Mb),as well as Sub1 and TPP7(Δbp:6 Mb)were identified to exhibit long-range linkage disequilibrium(LRLD).Meta-QTL analysis further revealed that Sub1 and TPP7 co-segregated for tolerance to submergence at the germination and seedling stages.Based on this,we hypothesized that LRLD might influence plant responses to consecutive stresses.To test this hypothesis,we developed a structured recombinant inbred line population from a cross between Bhalum 2 and Nagina 22,with alleles(Sub1 and TPP7)in linkage equilibrium.Mendelian randomization analysis validated that the parental alleles,rather than the recombinant alleles of Sub1 and TPP7,significantly influenced 13 out of 41 traits under consecutive stress conditions.Additionally,16 minor additive effect QTLs were detected between the genomic regions,spanning Sub1 and TPP7 for various traits.A single allele difference between these genomic regions enhanced crown root number,root dry weight,and specific root area by 11.45%,15.69%,and 33.15%,respectively,under flooded germination conditions.Candidate gene analysis identified WAK79 and MRLK59 as regulators of stress responses during flooded germination,recovery,and subsequent water deficit conditions.These findings highlight the critical role of parental allele combinations and genomic regions between Sub1 and TPP7 in regulating the stress responses under consecutive stresses.Favourable haplotypes derived from these alleles can be utilized to improve stress resilience in direct-seeded rice.展开更多
A new species of Anastatus Motschulsky, 1859 （Hymenoptera： Eupelmidae）, A. orientalis Yang ＆ Choi, sp. nov. is described from China. It is a solitary endo-parasitoid in egg of the spotted lanternfly, Lycorma delic...A new species of Anastatus Motschulsky, 1859 （Hymenoptera： Eupelmidae）, A. orientalis Yang ＆ Choi, sp. nov. is described from China. It is a solitary endo-parasitoid in egg of the spotted lanternfly, Lycorma delicatula （White） （Homoptera： Fulgoridae）, which causes damages to many ornamental and fruit trees in China. The brief biology of the new parasitoid is also mentioned. The new species has high potential as a biocontrol agent for suppression of the pest because of its parasitism rates of egg masses 30.4% and of eggs 40.2% respectively with sex ratio of female to male 1.9：1.0, as well as the relative easiness for mass rearing. The detailed feature characters and photos of the new species are supplied. Meanwhile, a key to distinguish the present new species from the other close two （A. japonicus and A. bifasciatus） in the genus is provided. Type specimens are deposited in the Insect Museum, Chinese Academy of Forestry, Beijing, China.展开更多
The occurrence of entomopathogenic nematodes(EPNs)in arable soil samples from Nigeria was investigated using Baermann extraction tray and insect-bait(White’s trap)techniques.Isolates were tested for infectivity using...The occurrence of entomopathogenic nematodes(EPNs)in arable soil samples from Nigeria was investigated using Baermann extraction tray and insect-bait(White’s trap)techniques.Isolates were tested for infectivity using the larvae of Galleria mellonella(greater moth)and Tenebrio molitor(mealworm).The study revealed a new species of Heterorhabditis(MT371593)in soil samples that were randomly collected from an arable farmland cultivated with cassava TMS-30572 at the Teaching and Research Farm of Landmark University,Nigeria.Amplification of the internal transcribed spacer region(ITS)of the ribosomal DNA produced a nucleotide sequence of 933 base pairs(bp).A BLASTN search of GenBank showed that the sequence of the Nigerian isolate is identical at 99%similarity to that of Heterorhabditis sp.from Thailand.Infectivity test of the isolate showed 100%mortality against T.molitor larvae within 48 h of exposure while only 80%mortality was recorded for G.mellonella after 1 week of exposure.This is the first account of Heterorhabditis sp.in Nigeria.The varying degrees of infectivity against mealworm and greater moth observed in this study proved that the Nigerian isolate of Heterorhabditis sp.could potentially be an attractive option in the management of insect pests of cash crops.展开更多
Biological control is usually the first choice of control and prevention method for integrated pest management （IPM） strategies and has now been widely implemented by Indonesian oil palm plantations. Entomopathogeni...Biological control is usually the first choice of control and prevention method for integrated pest management （IPM） strategies and has now been widely implemented by Indonesian oil palm plantations. Entomopathogenic fungus, i.e., Metarhizium anisopliae, Cordyceps militaris and Beauveria bassiana have been demonstrated to control renowned pests of oil palm. Metarhizium has been used to control Oryctes larvae and the mortality has ranged from 91.67% to 100% in laboratory and 7.4% to 88.75% in the field. Metarhizium has been applied in combination with a termite baiting system （TBS） to control termites in the field for preventive and curative action as well. In many oil palm plantations in Indonesia, Cordyceps has been used to reduce the field moth population ofSetothosea asigna. Application of Cordyceps within the oil palm circle was able to infect S. asigna pupae up to 80%. Meanwhile, Beauveria in an effervescent formulation was demonstrated to have better efficacy on Darna trima larvae. A significant finding on the biological control of basal stem rot disease （Ganoderma） was the isolation of Trichoderma sp. and Gliocladium sp.. The efficacy was conducted with promising result and techniques on the application of Triehoderma have been developed, i.e., hole-in-hole system, surgery and a mounding method. However, as the roots developed, Trichoderma was no longer able to protect the palm from Ganoderma. In spite of that, the use of Trichoderma still prolonged the life ofoil palms by up to 2-3 years. Another fungi belonging to vesicular arbuscular mychorrhiza （VAM） has been developed to control Ganoderma. The efficacy in the nursery showed promising results and the Ganoderma incidence remained low compared to the untreated control. Large scale field trials are ongoing. Challenges on the implementation of biological control in oil palm plantations are because of application and availability of biopesticides/natural enemies. Therefore, advances in research on the formulation of biological control agents are still needed.展开更多
Sahlbergella singularis （brown cocoa mirid） is responsible for over 30% yield loss of cocoa, while Phytophthora megakarya （causal organism of black pod disease） causes between 70-100% yield loss of cocoa in Nigeri...Sahlbergella singularis （brown cocoa mirid） is responsible for over 30% yield loss of cocoa, while Phytophthora megakarya （causal organism of black pod disease） causes between 70-100% yield loss of cocoa in Nigeria. In all the Nigerian cocoa agroecological zones, the use of pesticides still remains an important component among the strategies for effective control of major insect pests and diseases of cocoa. The Cocoa Research Institute of Nigeria （CRIN）, has the national mandate to evaluate and recommend novel pesticides from various groups that fall within the European-Union standards for use on cocoa farms in Nigeria. Such pesticides usually undergo rigorous testing spanning over 3 years to determine correct dose necessary to produce toxic reactions to the targeted pests without any adverse effects on the environment, man and non-target organisms. The screening exercise for candidate pesticides starts with confirmatory test of the constituent active ingredient, laboratory bioassay, phytotoxicity test, first, second and third year field evaluation and residue analysis of beans harvested from the treated plots. This paper critically examines these standard procedures, which must be followed judiciously for novel pesticides certification and recommendation for use in Nigeria.展开更多
Proteus 170O - TEQ insecticide was subjected through rigorous testing over years （2005 to 2008） at four concentrations 0.15% （9 mls/10L.H20）, 0.31% （18 mls/10L.H2O）, 0.46% （27 mls/10L.H2O） and 0.61% （36 mls/1...Proteus 170O - TEQ insecticide was subjected through rigorous testing over years （2005 to 2008） at four concentrations 0.15% （9 mls/10L.H20）, 0.31% （18 mls/10L.H2O）, 0.46% （27 mls/10L.H2O） and 0.61% （36 mls/10L.H2O）. Each concentration was replicated three times in the field. The mortality rates of mirids on exposure to the various concentrations of Proteus and Standard miricide in the laboratory were similar at 0.46% concentration as both gave a 100% kill ofmirids at the 40th minute. The first year field mortalities of mirids recorded 24 hours after the initial and residual applications at the Ibadan, Owena and Ikom at 0.46% active ingredient concentration gave 100% kill of mirids. The mortalities of mirids recorded 24 hours after the second year field initial and residual treatments at the lowest concentration of 0.15% active ingredient ranged between 70.2% and 100%. In the third year, the insecticide at 0.31% concentration compared favourably with the Standard. The residues of thiacloprid in the analyzed cocoa bean samples were below the Limit of Quantitation （LOQ） of 0.01 mg/kg. Spraying of mature and fruiting cocoa farms at application rate of 0.46% was found adequate and recommended.展开更多
基金supported by the Director General,Indian Council of Agricultural Research(ICAR),New Delhithe Director,ICAR-National Rice Research Institute,Cuttack.
文摘Consecutive stresses,such as initial submergence during germination followed by water deficit during the seedling stage,pose significant challenges to direct-seeded rice cultivation.By Linkage disequilibrium analysis,Sub1 and Dro1(Δbp:10 Mb),as well as Sub1 and TPP7(Δbp:6 Mb)were identified to exhibit long-range linkage disequilibrium(LRLD).Meta-QTL analysis further revealed that Sub1 and TPP7 co-segregated for tolerance to submergence at the germination and seedling stages.Based on this,we hypothesized that LRLD might influence plant responses to consecutive stresses.To test this hypothesis,we developed a structured recombinant inbred line population from a cross between Bhalum 2 and Nagina 22,with alleles(Sub1 and TPP7)in linkage equilibrium.Mendelian randomization analysis validated that the parental alleles,rather than the recombinant alleles of Sub1 and TPP7,significantly influenced 13 out of 41 traits under consecutive stress conditions.Additionally,16 minor additive effect QTLs were detected between the genomic regions,spanning Sub1 and TPP7 for various traits.A single allele difference between these genomic regions enhanced crown root number,root dry weight,and specific root area by 11.45%,15.69%,and 33.15%,respectively,under flooded germination conditions.Candidate gene analysis identified WAK79 and MRLK59 as regulators of stress responses during flooded germination,recovery,and subsequent water deficit conditions.These findings highlight the critical role of parental allele combinations and genomic regions between Sub1 and TPP7 in regulating the stress responses under consecutive stresses.Favourable haplotypes derived from these alleles can be utilized to improve stress resilience in direct-seeded rice.
文摘A new species of Anastatus Motschulsky, 1859 （Hymenoptera： Eupelmidae）, A. orientalis Yang ＆ Choi, sp. nov. is described from China. It is a solitary endo-parasitoid in egg of the spotted lanternfly, Lycorma delicatula （White） （Homoptera： Fulgoridae）, which causes damages to many ornamental and fruit trees in China. The brief biology of the new parasitoid is also mentioned. The new species has high potential as a biocontrol agent for suppression of the pest because of its parasitism rates of egg masses 30.4% and of eggs 40.2% respectively with sex ratio of female to male 1.9：1.0, as well as the relative easiness for mass rearing. The detailed feature characters and photos of the new species are supplied. Meanwhile, a key to distinguish the present new species from the other close two （A. japonicus and A. bifasciatus） in the genus is provided. Type specimens are deposited in the Insect Museum, Chinese Academy of Forestry, Beijing, China.
基金The authors are grateful to the Management of Landmark University for financial assistance and to Prof.A.P.Malan of the Department of Conservation Ecology&Entomology,Stellenbosch University,South Africa for providing guidance with molecular identification.
文摘The occurrence of entomopathogenic nematodes(EPNs)in arable soil samples from Nigeria was investigated using Baermann extraction tray and insect-bait(White’s trap)techniques.Isolates were tested for infectivity using the larvae of Galleria mellonella(greater moth)and Tenebrio molitor(mealworm).The study revealed a new species of Heterorhabditis(MT371593)in soil samples that were randomly collected from an arable farmland cultivated with cassava TMS-30572 at the Teaching and Research Farm of Landmark University,Nigeria.Amplification of the internal transcribed spacer region(ITS)of the ribosomal DNA produced a nucleotide sequence of 933 base pairs(bp).A BLASTN search of GenBank showed that the sequence of the Nigerian isolate is identical at 99%similarity to that of Heterorhabditis sp.from Thailand.Infectivity test of the isolate showed 100%mortality against T.molitor larvae within 48 h of exposure while only 80%mortality was recorded for G.mellonella after 1 week of exposure.This is the first account of Heterorhabditis sp.in Nigeria.The varying degrees of infectivity against mealworm and greater moth observed in this study proved that the Nigerian isolate of Heterorhabditis sp.could potentially be an attractive option in the management of insect pests of cash crops.
文摘Biological control is usually the first choice of control and prevention method for integrated pest management （IPM） strategies and has now been widely implemented by Indonesian oil palm plantations. Entomopathogenic fungus, i.e., Metarhizium anisopliae, Cordyceps militaris and Beauveria bassiana have been demonstrated to control renowned pests of oil palm. Metarhizium has been used to control Oryctes larvae and the mortality has ranged from 91.67% to 100% in laboratory and 7.4% to 88.75% in the field. Metarhizium has been applied in combination with a termite baiting system （TBS） to control termites in the field for preventive and curative action as well. In many oil palm plantations in Indonesia, Cordyceps has been used to reduce the field moth population ofSetothosea asigna. Application of Cordyceps within the oil palm circle was able to infect S. asigna pupae up to 80%. Meanwhile, Beauveria in an effervescent formulation was demonstrated to have better efficacy on Darna trima larvae. A significant finding on the biological control of basal stem rot disease （Ganoderma） was the isolation of Trichoderma sp. and Gliocladium sp.. The efficacy was conducted with promising result and techniques on the application of Triehoderma have been developed, i.e., hole-in-hole system, surgery and a mounding method. However, as the roots developed, Trichoderma was no longer able to protect the palm from Ganoderma. In spite of that, the use of Trichoderma still prolonged the life ofoil palms by up to 2-3 years. Another fungi belonging to vesicular arbuscular mychorrhiza （VAM） has been developed to control Ganoderma. The efficacy in the nursery showed promising results and the Ganoderma incidence remained low compared to the untreated control. Large scale field trials are ongoing. Challenges on the implementation of biological control in oil palm plantations are because of application and availability of biopesticides/natural enemies. Therefore, advances in research on the formulation of biological control agents are still needed.
文摘Sahlbergella singularis （brown cocoa mirid） is responsible for over 30% yield loss of cocoa, while Phytophthora megakarya （causal organism of black pod disease） causes between 70-100% yield loss of cocoa in Nigeria. In all the Nigerian cocoa agroecological zones, the use of pesticides still remains an important component among the strategies for effective control of major insect pests and diseases of cocoa. The Cocoa Research Institute of Nigeria （CRIN）, has the national mandate to evaluate and recommend novel pesticides from various groups that fall within the European-Union standards for use on cocoa farms in Nigeria. Such pesticides usually undergo rigorous testing spanning over 3 years to determine correct dose necessary to produce toxic reactions to the targeted pests without any adverse effects on the environment, man and non-target organisms. The screening exercise for candidate pesticides starts with confirmatory test of the constituent active ingredient, laboratory bioassay, phytotoxicity test, first, second and third year field evaluation and residue analysis of beans harvested from the treated plots. This paper critically examines these standard procedures, which must be followed judiciously for novel pesticides certification and recommendation for use in Nigeria.
文摘Proteus 170O - TEQ insecticide was subjected through rigorous testing over years （2005 to 2008） at four concentrations 0.15% （9 mls/10L.H20）, 0.31% （18 mls/10L.H2O）, 0.46% （27 mls/10L.H2O） and 0.61% （36 mls/10L.H2O）. Each concentration was replicated three times in the field. The mortality rates of mirids on exposure to the various concentrations of Proteus and Standard miricide in the laboratory were similar at 0.46% concentration as both gave a 100% kill ofmirids at the 40th minute. The first year field mortalities of mirids recorded 24 hours after the initial and residual applications at the Ibadan, Owena and Ikom at 0.46% active ingredient concentration gave 100% kill of mirids. The mortalities of mirids recorded 24 hours after the second year field initial and residual treatments at the lowest concentration of 0.15% active ingredient ranged between 70.2% and 100%. In the third year, the insecticide at 0.31% concentration compared favourably with the Standard. The residues of thiacloprid in the analyzed cocoa bean samples were below the Limit of Quantitation （LOQ） of 0.01 mg/kg. Spraying of mature and fruiting cocoa farms at application rate of 0.46% was found adequate and recommended.
