[Objective]This study aimed to explore the population pattern characteristics of evergreen broad-leaved forest in Guanshan National Nature Reserve,Jiangxi Province.[Method]Based on the investigation data of the dynamic monitoring sample plot of evergreen broad-leaved forest in Guanshan(12 hm2),Jiangxi Province,the distribution pattern,intergenerational relationship and interspecific relationship of dominant species in the sample plot were analyzed,according to the coordinate information of tree points.[Result](1)The dominant species were mainly concentrated,and 90%of the species were concentrated within 25 m,but with the increase of the scale,the tree species gradually turned to random distribution;(2)Among the dominant tree species,the large trees of most evergreen tree species were positively correlated with small trees,such as Daphniphyllum oldhamii and Schima superba;while,the large trees and small trees of deciduous species were negatively correlated,such as Alniphyllum fortunei and Choerospondias axillaris;(3)The dominant species mainly existed in the form of negative correlation,and only 5 species pairs were found to be positively correlated.[Conclusion]The community is still in the early stage of development,the dominant species are mainly concentrated and distributed,and the interspecific competition is fierce.
[Objective]Cryptosporidium,Enterocytozoon bieneusi and Blastocystis sp.are three common parasites,which inhabit in the intestines of humans,domestic animals,and wildlife,primarily causing diarrhea in human and animals.This experiment aimed to investigate the epidemiological status and identify their genotypes of three parasites among captive animals in Nanchang Zoo,and provide references for the prevention and treatment of intestinal parasitic diseases in wild animals.[Method]A total of 42 fecal samples were collected from captive animals including non-human primates,ungulates,perissodactyls,elephants,marsupials,birds,and carnivores in Nanchang Zoo.Total DNA was extracted from the fecal samples,and a PCR assay was employed to amplify the small subunit ribosomal RNA(SSU rRNA)gene of Cryptosporidium,the internal transcribed spacer(ITS)region of E.bieneusi,and the SSU rRNA gene of Blastocystis sp..Positive amplicons were sequenced,aligned,and subjected to phylogenetic analysis to determine the infection status and genotypes/subtypes of these three intestinal parasites.[Result]The results indicated that 17 out of 42 fecal samples were positive by PCR,with a total infection rate of 40.5%(17/42).The infection rates of Cryptosporidium,E.bieneusi,and Blastocystis sp.were 2.4%(1/42),14.3%(6/42),and 23.8%(10/42),respectively.Among the detected animals,the positivity rates were as follows:non-human primates 64.7%(11/17),ungulates 23.5%(4/17),perissodactyls 5.9%(1/17),and marsupials 5.9%(1/17).Furthermore,mixed infections of E.bieneusi and Blastocystis sp.were observed in non-human primates.Through sequence alignment and phylogenetic analysis,one Cryptosporidium genotype(Cryptosporidium sp.apodemus genotype Ⅱ)was identified in ponies,and two E.bieneusi genotypes(D,ALP1)were identified in gibbons,golden snub-nosed monkeys,rhesus monkeys,red-tailed langurs,and alpacas.Five Blastocystis sp.subtypes(ST1,ST2,ST5,ST13,and ST14)were identified in squirrel monkeys,black-and-white colobus monkeys,rhesus monkeys,black leaf monkeys,golden snub-nosed monkeys,antelopes,and kangaroos.Notably,the genotypes ST1,ST5,D,and ALP1 are known as zoonotic genotypes.[Conclusion]Captive animals in Nanchang Zoo were infected with Cryptosporidium,E.bieneusi and Blastocystis sp..The zoonotic genotypes are identified from E.bieneusi and Blastocystis sp.,which have a potential transmission risk.This underscores the need for enhanced monitoring of intestinal protozoa in captive animals,and the implementation of deworming,disinfection,and preventive measures against zoonotic transmission within the zoo setting.
[Objective]To establish a method for rapid detection of Southern rice black-streaked dwarf virus(SRBSDV)and study the function of P7-2 gene,it is necessary to prepare specific antiserum of P7-2.[Method]The P7-2 gene was amplified by RT-PCR from the rice leaves infected with SRBSDV.The purified PCR fragment of P7-2 gene was subcloned into the prokaryotic expression vector pDEST17 to obtain the recombinant prokaryotic expression vector pDEST17-P7-2 by Gateway recombinant technology.Then the recombinant vector was transformed into E.coli Rosetta cells,which was induced by IPTG to express the protein and optimize the induced expression conditions.[Result]Sequence of the 930 bp SRBSDV P7-2 was amplified by RT PCR.The sequencing results showed that the prokaryotic expression vector pDEST17-P7-2 was obtained.The positive prokaryotic expression of E.coli Rosetta strains was identified by PCR.A large number of 42 kDa HIS6-tag fusion protein was obtained with the induction of 0.1 mmol/L IPTG from E.coli Rosetta cells for 8 h when the temperature was 28℃.[Conclusion]SRBSDV P7-2 gene was obtained and its protein was induced successfully under the optimal conditions,which laid a foundation for the detection and prediction of SRBSDV in the field as well as for the function study of SRBSDV P7-2.
[Objective]The long-term and unreasonable use of chemical pesticides has led to the resistance of Spodoptera litura to insecticides such as pyrethroids and available phosphorus.Bufenitrile is a pyrrole insecticide with a wide insecticidal spectrum,high control effects,good persistence,and safety,making its use more and more widespread.[Method]This study used the leaf soaking method to determine the toxicity of imidacloprid to the 3rd instar larvae of Spodoptera litura.Different carriers were used to treat the 3rd instar larvae of Spodoptera litura with sublethal doses of LC10 and LC30,and the effects of larval weight,pupation rates,pupal weight,and female ratios were recorded.[Result]The pupation rates and female ratios were significantly reduced.The growth and development of the 3rd instar larvae of Spodoptera litura treated with sublethal doses of imidacloprid were severely inhibited,mainly manifested in a significant decrease in larval body mass,pupation rates and female ratios,and a significant reduction in pupal weight.[Conclusion]Imidacloprid has a good effect on the control of Spodoptera litura,and the control should be done in the early larval stage.The research results can provide scientific basis for guiding the rational application of imidacloprid to prevent and control pests such as Spodoptera litura.
Food microorganisms are one of the important factors affecting food safety.The adoption of new rapid detection methods to promptly identify food safety hazards and then to take corresponding measures can help improve the efficiency of food safety supervision and ensure food safety.Flow cytometry can be used for multi-parameter qualitative and quantitative analyses of food microorganisms,such as distinguishing between the dead and alive,counting,and population identification.It provides a new approach to solve the problems of insufficient timeliness,difficulty in distinguishing between the dead and alive,and inability to detect non cultured microorganisms in the plate detection methods.This article provides a summary of the research and application of flow cytometry in the field of food microbiology detection.It also provides a detailed introduction to the experimental process,key influencing factors,and research progress of flow cytometry detection.Besides,it explores and analyzes the problems existing in the application of this method,in order to provide strategies for the widespread application of flow cytometry in the field of food microbiology detection,so as to ensure food safety.
