[Objective] This study aimed to uncover the biological characteristics of a parasitical fungus in Chrysosp/enium absconditicapsu/um J. T. Pan leaves. [Method] PDA medium was used to isolate the fungus from C. abscondi...[Objective] This study aimed to uncover the biological characteristics of a parasitical fungus in Chrysosp/enium absconditicapsu/um J. T. Pan leaves. [Method] PDA medium was used to isolate the fungus from C. absconditicapsulum leaves; PDA medium, modified KB medium and Czapek medium were adopted to cultivate the isolated strain. [Result] Colonies of the strain were stretched, white, fedora- shaped with smooth and wavy edges, and showed diameter growth on PDA medi- um, modified KB medium and Czapek medium. At the late stage of culture, the colonies turned into cyanish brown on the above media. Spores were black and born on the surface of colonies on PDA medium with blackened medium. While on modified KB medium and Czapek medium, they were born at the edge of colonies with blackened medium. The spores varied in a wide range of shapes, mostly ob- clavate, sometimes spherical or ellipsoidal. The conidia were muriformly septate with transverse or longitudinal or oblique septations. The pseudo-beaks were short and cylindrical. [Conclusion] According to relevant literatures, the isolated strain is a fungus in Alternaria, Dematiaceae, Hylohomycetales, Hyphomycetes, Deuteromycotina.展开更多
Aflatoxins are secondary metabolites of fungi such as Aspergillus flavus and Aspergillus parasiticus. They are one of the contaminants most common in food and feed, with high toxicity and carcinogenicity. Aflatoxins u...Aflatoxins are secondary metabolites of fungi such as Aspergillus flavus and Aspergillus parasiticus. They are one of the contaminants most common in food and feed, with high toxicity and carcinogenicity. Aflatoxins usually enter animal body together with feed and then enter human body by food chain, thereby seriously threatening human health. In recent years, the degradation of aflatoxins has become a hot research topic. This study overviewed the characteristics and detoxification ways of aflatoxins, specifically for the advances in biodegradation and degradation products of aflatoxins.展开更多
Sericea lespedeza （Lespedeza cuneata （Dum. Cours.） G. Don.） has historically been called ＂poor man＇s alfalfa＂, because of its ability to grow on marginal soil with the minimal inputs of lime or fertilizer. With...Sericea lespedeza （Lespedeza cuneata （Dum. Cours.） G. Don.） has historically been called ＂poor man＇s alfalfa＂, because of its ability to grow on marginal soil with the minimal inputs of lime or fertilizer. With recent research detailing the potential health benefits of this forage to animals, it may be time for a new nickname. Although sericea lespedeza has been used for soil conservation and as an inexpensive （low-input） source of pasture or hay crop for nearly 100 years, research over the last 10-15 years has demonstrated the excellent bioactivity of this plant against infection with gastrointestinal nematodes （Haemonchus contortus） and protozoan parasites （Eimeria spp.） in livestock. This bioactivity, which has been attributed to a unique type of condensed tannins （CT）, has been confirmed in both fresh （grazed） and dried （hay, meal, pellets） forms of sericea lespedeza in a number of studies with sheep, goats, and cattle. There is on-going research with this forage to determine the effect of ensiling on its bioactive properties and to validate its anti-parasitic effects on-farm. Future research will focus on determining the mode of action of sericea lespedeza tannins against internal parasites and the interplay between the nutritional value and the health benefits of this plant.展开更多
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
In haplodiploid Hymenoptera, unfertilized eggs produce haploid males while fertilized eggs lead to diploid females under most circumstances. Diploid males can also be produced from fertilization under a system of sex ...In haplodiploid Hymenoptera, unfertilized eggs produce haploid males while fertilized eggs lead to diploid females under most circumstances. Diploid males can also be produced from fertilization under a system of sex determination known as complementary sex determination (CSD). Under single-locus CSD, sex is determined by multiple alleles at a single sex locus. Individuals heterozygous at the sex locus are female while hemizygous and homozygous individuals develop as haploid and diploid males, respectively. In multiple-locus CSD, two or more loci, each with two or more alleles, determine sex. Diploid individuals are female if one or more sex loci are het-erozygous, while a diploid is male only if homozygous at all sex loci. Diploid males are known to occur in 43 hym-enopteran species and single-locus CSD has been demonstrated in 22 of these species. Diploid males are either developmentally inviable or sterile, so their production constitutes a genetic load. Because diploid male production is more likely under inbreeding, CSD is a form of inbreeding depression. It is crucial to preserve the diversity of sex alleles and reduce the loss of genetic variation in biological control. In the parasitoid species with single-locus CSD, certain precautionary procedures can prevent negative effects of single-locus CSD on biological control.展开更多
文摘[Objective] This study aimed to uncover the biological characteristics of a parasitical fungus in Chrysosp/enium absconditicapsu/um J. T. Pan leaves. [Method] PDA medium was used to isolate the fungus from C. absconditicapsulum leaves; PDA medium, modified KB medium and Czapek medium were adopted to cultivate the isolated strain. [Result] Colonies of the strain were stretched, white, fedora- shaped with smooth and wavy edges, and showed diameter growth on PDA medi- um, modified KB medium and Czapek medium. At the late stage of culture, the colonies turned into cyanish brown on the above media. Spores were black and born on the surface of colonies on PDA medium with blackened medium. While on modified KB medium and Czapek medium, they were born at the edge of colonies with blackened medium. The spores varied in a wide range of shapes, mostly ob- clavate, sometimes spherical or ellipsoidal. The conidia were muriformly septate with transverse or longitudinal or oblique septations. The pseudo-beaks were short and cylindrical. [Conclusion] According to relevant literatures, the isolated strain is a fungus in Alternaria, Dematiaceae, Hylohomycetales, Hyphomycetes, Deuteromycotina.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303080)Chenguang Planning Project for Fostering Scientific and Technological Talents in Wuhan City(2015070404010189)Project of Hubei Agricultural Science and Technology Innovation Center(2016-620-000-001-033)
文摘Aflatoxins are secondary metabolites of fungi such as Aspergillus flavus and Aspergillus parasiticus. They are one of the contaminants most common in food and feed, with high toxicity and carcinogenicity. Aflatoxins usually enter animal body together with feed and then enter human body by food chain, thereby seriously threatening human health. In recent years, the degradation of aflatoxins has become a hot research topic. This study overviewed the characteristics and detoxification ways of aflatoxins, specifically for the advances in biodegradation and degradation products of aflatoxins.
文摘Sericea lespedeza （Lespedeza cuneata （Dum. Cours.） G. Don.） has historically been called ＂poor man＇s alfalfa＂, because of its ability to grow on marginal soil with the minimal inputs of lime or fertilizer. With recent research detailing the potential health benefits of this forage to animals, it may be time for a new nickname. Although sericea lespedeza has been used for soil conservation and as an inexpensive （low-input） source of pasture or hay crop for nearly 100 years, research over the last 10-15 years has demonstrated the excellent bioactivity of this plant against infection with gastrointestinal nematodes （Haemonchus contortus） and protozoan parasites （Eimeria spp.） in livestock. This bioactivity, which has been attributed to a unique type of condensed tannins （CT）, has been confirmed in both fresh （grazed） and dried （hay, meal, pellets） forms of sericea lespedeza in a number of studies with sheep, goats, and cattle. There is on-going research with this forage to determine the effect of ensiling on its bioactive properties and to validate its anti-parasitic effects on-farm. Future research will focus on determining the mode of action of sericea lespedeza tannins against internal parasites and the interplay between the nutritional value and the health benefits of this plant.
文摘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.
文摘In haplodiploid Hymenoptera, unfertilized eggs produce haploid males while fertilized eggs lead to diploid females under most circumstances. Diploid males can also be produced from fertilization under a system of sex determination known as complementary sex determination (CSD). Under single-locus CSD, sex is determined by multiple alleles at a single sex locus. Individuals heterozygous at the sex locus are female while hemizygous and homozygous individuals develop as haploid and diploid males, respectively. In multiple-locus CSD, two or more loci, each with two or more alleles, determine sex. Diploid individuals are female if one or more sex loci are het-erozygous, while a diploid is male only if homozygous at all sex loci. Diploid males are known to occur in 43 hym-enopteran species and single-locus CSD has been demonstrated in 22 of these species. Diploid males are either developmentally inviable or sterile, so their production constitutes a genetic load. Because diploid male production is more likely under inbreeding, CSD is a form of inbreeding depression. It is crucial to preserve the diversity of sex alleles and reduce the loss of genetic variation in biological control. In the parasitoid species with single-locus CSD, certain precautionary procedures can prevent negative effects of single-locus CSD on biological control.
