The paper summarizes the structure and water-absorbing mechanism,classification,and preparation method of polymer fire extinguishing gel,and prospects for its application in aerial firefighting,forest ground fire exti...The paper summarizes the structure and water-absorbing mechanism,classification,and preparation method of polymer fire extinguishing gel,and prospects for its application in aerial firefighting,forest ground fire extinguishing,opening of firebreaks,and mitigating human casualties in forest fire extinguishing.展开更多
Studying contents and seasonal dynamics of active organic carbon in the soil is an important method for revealing the turnover and regulation mechanism of soil carbon pool. Through 3 years of field sampling and lab an...Studying contents and seasonal dynamics of active organic carbon in the soil is an important method for revealing the turnover and regulation mechanism of soil carbon pool. Through 3 years of field sampling and lab analysis, we studied the seasonal variations, content differences, and interrelationships of total organic carbon (TOC), light fraction organic carbon (LFOC), and particulate organic carbon (POC) of the soil in the forest areas burned with different fire intensities in the Daxing'anling Mountains. The mean TOC content in the low-intensity burned area was greater than that in the unburned area, moderate-intensity, and high-intensity burned areas in June and November (P 〈 0.05). LFOC and POC in the low-intensity burned area were greater than that in either moderate-intensity or high-intensity burned areas, with significant differences in LFOC in September and November (P 〈 0.05). A significant difference in LFOC between the unburned and burned areas was only found in July (P 〈 0.05). However, the differences in POC between the unburned and burned areas were not significant in all the whole seasons (P 〉 0.05). Soil LFOC and POC varied significantly with the seasons (P 〈 0.05) in the Daxing'anling Mountains. Significant linear relationships were observed between soil TOC, LFOC, and POC, which were positively correlated with soil nitrogen and negatively correlated with soil temperature in the Daxing'anling Mountains.展开更多
The hazelnut weevil(Curculio dieckmanni Faust.)is a major pest of Asian hazel(Corylus heterophylla Fisch.)in China.Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identifi ed as S...The hazelnut weevil(Curculio dieckmanni Faust.)is a major pest of Asian hazel(Corylus heterophylla Fisch.)in China.Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identifi ed as Serratia marcescens Bizio.This signifi cantly shortened the lifespan of hazelnut weevil.Larval weight was reduced as a function of S.marcescens concentration and exposure time.The structure of infected midgut cells was altered,with necrosis of the wall tissues and many cells becoming dislodged,creating cavities.The S.marcencens strain inhibited digestive enzyme activity and protective enzymes in the midgut of adult hazelnut weevil.Inhibition on S.marcencens strain increased with treatment time.S.marcescens directly destroyed the midgut cells and interfered with digestive and protective enzymes.This decreased the food intake and increased mortality of hazelnut weevil.S.marcescens appears to be an eff ective bacterium for the control of hazelnut weevil but requires further study,including biological formulation development and fi eld application.展开更多
A PCR-ELISA method for detecting the glyphosate resistant transgenic soybean was established and optimized. The results showed that the key parameters of PCR-ELISA were as follows: the concentration of digoxin tag pr...A PCR-ELISA method for detecting the glyphosate resistant transgenic soybean was established and optimized. The results showed that the key parameters of PCR-ELISA were as follows: the concentration of digoxin tag probe was 0.5 μmol · L^-1, the time of hybridization reaction was 15 min and the chromogenic reaction should last for 30 min. The sensitivity and the repeatability of our PCR-ELISA method were evaluated, and the results showed that it could be detected when the concentration of DNA template from transgenic soybean samples was 0.01% or higher, and the coefficient of variation of this method was less than 5% in our research condition. These results suggested that PCR-ELISA method establishment in this study had good repeatability and high precision for detecting the transgenic soybean samples.展开更多
Spot fire increase the difficulty of fire-fighting and threaten public safety,and therefore it is important to study ignition probabilities of fuel bed by different firebrands,in order to understand ignition mechanism...Spot fire increase the difficulty of fire-fighting and threaten public safety,and therefore it is important to study ignition probabilities of fuel bed by different firebrands,in order to understand ignition mechanisms and analyze the formation of spot fires.This will provide an important basis for further study to improve the fire-fighting efficiency and reduce casualties.In this study,the ignition probabilities of larch(Larix gmelinii)fuel beds with different moisture levels and packing ratios by diffreent firebrands,including cones and twigs of different sizes,was investigated.Ignition experiments were conducted at different wind speeds generated by fans.The results show that,regardless of moisture content and packing ratio,ignition probability is zero when there is no wind.Both moisture content and wind speed significantly infuence ignition probability,while packing ratio has almost no effect.The maximum moisture content at which firebrand ignition occurred was 50%,and ignition probability increased with wind speed and decreased with moisture content.Cones have the highest ignition probability,followed by large twigs and by small twigs.Ignition probability is also affected by firebrand shapes and sizes that determine their potential heat and contact area to the fuel bed.Two empirical models were established to link ignition probability with fuel properties and wind speed.This study will help clarify the mechanism of spot ignition and reduce corresponding losses.展开更多
The Masculinizer gene,Masc,encodes a lepidopteran-specific novel CCCHtype zinc finger protein,which controls sex determination and dosage compensation in Bombyx mori.Considering the potential application of it in pest...The Masculinizer gene,Masc,encodes a lepidopteran-specific novel CCCHtype zinc finger protein,which controls sex determination and dosage compensation in Bombyx mori.Considering the potential application of it in pest control,it is necessary to investigate the function of Masc gene in Hyphantria cunea,a globally invasive forest pest.In the present study,we identified and functionally characterized the Masc gene,HcMasc,in H.cunea.Sequence analysis revealed that HcMASC contained the conserved CCCH-type zinc finger domain,nuclear localization signal,and male determining domain,in which the last was confirmed to be required for its masculinization in BmN cell line.However,expression data showed that unlike male-biased expression in B.mori,Hc-Masc gene expresses in main all developmental stages or tissues in both sexes.Clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-based disruption of the common exons 1 and 3 of the HcMasc gene resulted in imbalanced sex ratio and abnormal external genitalia of both sexes.Our results suggest that the HcMasc gene is required for both male and female sexual differentiation and dosage compensation in H.cunea and provide a foundation for developing better strategies to control this pest.展开更多
Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) is one of the preponderant egg parasitoids of Dendrolimus spp., which are important defoliators of coniferous forests. This parasitoid wasp has bee...Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) is one of the preponderant egg parasitoids of Dendrolimus spp., which are important defoliators of coniferous forests. This parasitoid wasp has been widely released to control pine caterpillar and other lepidopteran pests, but its control efficiency needs to be improved. Sensory systems are crucial for T dendrolimi to locate hosts, and immunity is probably involved after egg deposition in the host cavity; however, few reports have focused on the molecular mechanism of olfactory detection and survival of T. dendrolimi. It is necessary to identify these genes before further functional research is conducted. In this study, we assembled and analyzed the transcriptome of T. dendrolimi using next-generation sequencing technology. The sequencing and assembly resulted in 38 565 contigs with N50 of 3422 bp. Sequence comparison indicate that T dendrolimi sequences are very similar to those of another parasitoid Nasonia vitripennis. Then the olfactory, vision, and immune- related gene families were identified, and phylogenetic analyses were performed with these genes from T. dendrolimi and other model insect species. Furthermore, phylogenetic tree with odorant binding proteins of T. dendrolimi and their host Dendrolimus was constructed to determine whether convergent evolution exists. These genes can be valid targets for further gene function research. The present study may help us to understand host location and survival mechanisms of T dendrolimi and to use them more efficiently for pest control in the future.展开更多
Pine caterpillar moths, Dendrolimus spp. (Lepidoptera: Lasiocampidae), are serious economic pest of pines. Previously, phylogenetic analyses of Dendrolimus using different methods yielded inconsistent results. The ...Pine caterpillar moths, Dendrolimus spp. (Lepidoptera: Lasiocampidae), are serious economic pest of pines. Previously, phylogenetic analyses of Dendrolimus using different methods yielded inconsistent results. The chemosensory systems of insects may play fundamental roles in promoting speciation. Odorant-binding proteins (OBPs) participate in the first step of odor detection. Studying the evolution of OBPs in closely related species may help us to identify their role in speciation. We identified three OBPs - one pheromone-binding protein and two general odorant-binding proteins - from male antennae of four Dendrolimus species, D. superans (Butler), D. punctatus (Walker), D. kikuchii Matsumura, and D. houi Lajonquiere, the olfactory recognition systems of which had not been previously investigated. We analyzed their molecular characteristics and compared their sequences to those of OBPs in D. tabulaeformis Tsai et Liu. Ka/Ks ratio analyses among the five Dendrolimus species indicate that PBP1 genes experienced more evolutionary pressure than the GOBPs. Phylogenetic relationships of PBP1 and GOBP1 both indicated that D. houi was the basal species, then branched D. kikuchii, while D. tabulaeformis, D. punctatus, and D. superans evolved more recently. These relationships are consistent with the changes in sex pheromone components of these five species. Dendrolimus tabulaeformis and D. punctatus are closely related sister species. However, the distances among GOBP2 sequences in the five Dendrolimus were very short, and the relationships of D. houi and D. la'kuchii could not be resolved. Integrating our results with those of previous studies, we hypothesized that D. kikuchii, D. punctatus and D. superans evolved from the basal ancestor because of sex pheromone mutations and environmental pressure.展开更多
基金Central Finance Forestry Science and Technology Promotion Demonstration Project(H[2023]TG31).
文摘The paper summarizes the structure and water-absorbing mechanism,classification,and preparation method of polymer fire extinguishing gel,and prospects for its application in aerial firefighting,forest ground fire extinguishing,opening of firebreaks,and mitigating human casualties in forest fire extinguishing.
基金supported by the Ministry of Science and Technology project 973(2011CB403203)Youth science foundations in Heilongjiang province(QC2012C003)Youth science foundations in college of forest in Heilingjiang province(201415)
文摘Studying contents and seasonal dynamics of active organic carbon in the soil is an important method for revealing the turnover and regulation mechanism of soil carbon pool. Through 3 years of field sampling and lab analysis, we studied the seasonal variations, content differences, and interrelationships of total organic carbon (TOC), light fraction organic carbon (LFOC), and particulate organic carbon (POC) of the soil in the forest areas burned with different fire intensities in the Daxing'anling Mountains. The mean TOC content in the low-intensity burned area was greater than that in the unburned area, moderate-intensity, and high-intensity burned areas in June and November (P 〈 0.05). LFOC and POC in the low-intensity burned area were greater than that in either moderate-intensity or high-intensity burned areas, with significant differences in LFOC in September and November (P 〈 0.05). A significant difference in LFOC between the unburned and burned areas was only found in July (P 〈 0.05). However, the differences in POC between the unburned and burned areas were not significant in all the whole seasons (P 〉 0.05). Soil LFOC and POC varied significantly with the seasons (P 〈 0.05) in the Daxing'anling Mountains. Significant linear relationships were observed between soil TOC, LFOC, and POC, which were positively correlated with soil nitrogen and negatively correlated with soil temperature in the Daxing'anling Mountains.
基金the National Key Research and Development project of China(2016YFC0500308)Special Project for Double First-Class-Cultivation of Innovative Talents(000/41113102)+1 种基金the Natural Science Foundation of Heilongjiang Scientifi c Committee(C2018055)the Application Research Project of Heilongjiang Provincial Forest Industry Administration(sgzjY2014004).
文摘The hazelnut weevil(Curculio dieckmanni Faust.)is a major pest of Asian hazel(Corylus heterophylla Fisch.)in China.Dead hazelnut weevil larvae were examined and the associated pathogenic bacterium was identifi ed as Serratia marcescens Bizio.This signifi cantly shortened the lifespan of hazelnut weevil.Larval weight was reduced as a function of S.marcescens concentration and exposure time.The structure of infected midgut cells was altered,with necrosis of the wall tissues and many cells becoming dislodged,creating cavities.The S.marcencens strain inhibited digestive enzyme activity and protective enzymes in the midgut of adult hazelnut weevil.Inhibition on S.marcencens strain increased with treatment time.S.marcescens directly destroyed the midgut cells and interfered with digestive and protective enzymes.This decreased the food intake and increased mortality of hazelnut weevil.S.marcescens appears to be an eff ective bacterium for the control of hazelnut weevil but requires further study,including biological formulation development and fi eld application.
文摘A PCR-ELISA method for detecting the glyphosate resistant transgenic soybean was established and optimized. The results showed that the key parameters of PCR-ELISA were as follows: the concentration of digoxin tag probe was 0.5 μmol · L^-1, the time of hybridization reaction was 15 min and the chromogenic reaction should last for 30 min. The sensitivity and the repeatability of our PCR-ELISA method were evaluated, and the results showed that it could be detected when the concentration of DNA template from transgenic soybean samples was 0.01% or higher, and the coefficient of variation of this method was less than 5% in our research condition. These results suggested that PCR-ELISA method establishment in this study had good repeatability and high precision for detecting the transgenic soybean samples.
基金funded by the Sub topic of 13th Five-Year-Plan National Key Research and Development Project(2017YFD0600106-2)National Natural Science Foundation Project(31,400,551,31,870,644)。
文摘Spot fire increase the difficulty of fire-fighting and threaten public safety,and therefore it is important to study ignition probabilities of fuel bed by different firebrands,in order to understand ignition mechanisms and analyze the formation of spot fires.This will provide an important basis for further study to improve the fire-fighting efficiency and reduce casualties.In this study,the ignition probabilities of larch(Larix gmelinii)fuel beds with different moisture levels and packing ratios by diffreent firebrands,including cones and twigs of different sizes,was investigated.Ignition experiments were conducted at different wind speeds generated by fans.The results show that,regardless of moisture content and packing ratio,ignition probability is zero when there is no wind.Both moisture content and wind speed significantly infuence ignition probability,while packing ratio has almost no effect.The maximum moisture content at which firebrand ignition occurred was 50%,and ignition probability increased with wind speed and decreased with moisture content.Cones have the highest ignition probability,followed by large twigs and by small twigs.Ignition probability is also affected by firebrand shapes and sizes that determine their potential heat and contact area to the fuel bed.Two empirical models were established to link ignition probability with fuel properties and wind speed.This study will help clarify the mechanism of spot ignition and reduce corresponding losses.
基金funded by the Strategic Priority Research Program of Chinese Academy of Sciences(XDB11010600)National Natural Science Foundation of China(32101531 and 31420103918)National Key Research and Development Program of China,grant number 2018YFD0600203.
文摘The Masculinizer gene,Masc,encodes a lepidopteran-specific novel CCCHtype zinc finger protein,which controls sex determination and dosage compensation in Bombyx mori.Considering the potential application of it in pest control,it is necessary to investigate the function of Masc gene in Hyphantria cunea,a globally invasive forest pest.In the present study,we identified and functionally characterized the Masc gene,HcMasc,in H.cunea.Sequence analysis revealed that HcMASC contained the conserved CCCH-type zinc finger domain,nuclear localization signal,and male determining domain,in which the last was confirmed to be required for its masculinization in BmN cell line.However,expression data showed that unlike male-biased expression in B.mori,Hc-Masc gene expresses in main all developmental stages or tissues in both sexes.Clustered regularly interspaced palindromic repeats(CRISPR)/CRISPR-associated protein 9-based disruption of the common exons 1 and 3 of the HcMasc gene resulted in imbalanced sex ratio and abnormal external genitalia of both sexes.Our results suggest that the HcMasc gene is required for both male and female sexual differentiation and dosage compensation in H.cunea and provide a foundation for developing better strategies to control this pest.
基金Acknowledgments We express many thanks that Institute Special Fund for Basic Research, Institute of Forest Ecology, Environment, and Protection, Chinese Academy of Forestry (CAFRIFEEP201406, CAFRIFEEP201102-5) and the National Natural Science Foundation of China (31200492) supported this work. SFZ designed the experiments, carried out the laboratory work, analyzed the data and drafted the manuscript. ZZ designed the experiments and modified the manuscript. HBW and XBK modified the manuscript, and GZ and JXY reared and applied insects.
文摘Trichogramma dendrolimi Matsumura (Hymenoptera: Trichogrammatidae) is one of the preponderant egg parasitoids of Dendrolimus spp., which are important defoliators of coniferous forests. This parasitoid wasp has been widely released to control pine caterpillar and other lepidopteran pests, but its control efficiency needs to be improved. Sensory systems are crucial for T dendrolimi to locate hosts, and immunity is probably involved after egg deposition in the host cavity; however, few reports have focused on the molecular mechanism of olfactory detection and survival of T. dendrolimi. It is necessary to identify these genes before further functional research is conducted. In this study, we assembled and analyzed the transcriptome of T. dendrolimi using next-generation sequencing technology. The sequencing and assembly resulted in 38 565 contigs with N50 of 3422 bp. Sequence comparison indicate that T dendrolimi sequences are very similar to those of another parasitoid Nasonia vitripennis. Then the olfactory, vision, and immune- related gene families were identified, and phylogenetic analyses were performed with these genes from T. dendrolimi and other model insect species. Furthermore, phylogenetic tree with odorant binding proteins of T. dendrolimi and their host Dendrolimus was constructed to determine whether convergent evolution exists. These genes can be valid targets for further gene function research. The present study may help us to understand host location and survival mechanisms of T dendrolimi and to use them more efficiently for pest control in the future.
基金Acknowledgments We thank Lin Xiong and Xi-Yong Huang for providing the insects. We are grateful to anonymous reviewers for valuable comments and suggestions on earlier versions of this manuscript. This work was supported by the National Natural Science Foundation of China (31200492) and the Institute Special Fund for Basic Research, Institute of Forest Ecology, Environment, and Protection, Chinese Academy of Forestry (CAFRIFEEP201102-5).
文摘Pine caterpillar moths, Dendrolimus spp. (Lepidoptera: Lasiocampidae), are serious economic pest of pines. Previously, phylogenetic analyses of Dendrolimus using different methods yielded inconsistent results. The chemosensory systems of insects may play fundamental roles in promoting speciation. Odorant-binding proteins (OBPs) participate in the first step of odor detection. Studying the evolution of OBPs in closely related species may help us to identify their role in speciation. We identified three OBPs - one pheromone-binding protein and two general odorant-binding proteins - from male antennae of four Dendrolimus species, D. superans (Butler), D. punctatus (Walker), D. kikuchii Matsumura, and D. houi Lajonquiere, the olfactory recognition systems of which had not been previously investigated. We analyzed their molecular characteristics and compared their sequences to those of OBPs in D. tabulaeformis Tsai et Liu. Ka/Ks ratio analyses among the five Dendrolimus species indicate that PBP1 genes experienced more evolutionary pressure than the GOBPs. Phylogenetic relationships of PBP1 and GOBP1 both indicated that D. houi was the basal species, then branched D. kikuchii, while D. tabulaeformis, D. punctatus, and D. superans evolved more recently. These relationships are consistent with the changes in sex pheromone components of these five species. Dendrolimus tabulaeformis and D. punctatus are closely related sister species. However, the distances among GOBP2 sequences in the five Dendrolimus were very short, and the relationships of D. houi and D. la'kuchii could not be resolved. Integrating our results with those of previous studies, we hypothesized that D. kikuchii, D. punctatus and D. superans evolved from the basal ancestor because of sex pheromone mutations and environmental pressure.