Three hundred and one endophytic bacteria strains were isolated from healthy sugar beet plants in severely diseased plots in Changji County,Xinjiang Province.Three endophytic bacteria strains,1-5,4-1 and 4-3,showed re...Three hundred and one endophytic bacteria strains were isolated from healthy sugar beet plants in severely diseased plots in Changji County,Xinjiang Province.Three endophytic bacteria strains,1-5,4-1 and 4-3,showed relatively strong antagonistic against Cercospora beticola.Strain 1-5 was identified as Paenibacillus polymyxa,while strains 4-1 and 4-3 were as Bacillus flexus and Stenotrophomonas sp. by their morphological,physiological and biochemical characteristics.The results from several experiment trials showed that the endophytic bacteria could reduce the disease incidence of sugar beet.The control efficiency reached from 67.6% to 80.2%, indicating that biocontrol with endophytic bacteria was an alternative and potential method to control sugar beet fungi disease.展开更多
The toxicity of insecticides to S.exigua different in generations and instars was tested by topical application. The results that the toxicity of alpha cypermethrin, methomyl, profenofos, and chlorfluazuron to 4th ins...The toxicity of insecticides to S.exigua different in generations and instars was tested by topical application. The results that the toxicity of alpha cypermethrin, methomyl, profenofos, and chlorfluazuron to 4th instar was decreased among second, fourth and sixth generations, and that of alpha cypermythrin, methomyl, profenofos, and chlorfluazuron to third, fourth and fifth instar of sixth generation was also decreased. These gave a viewpoint that the resistance develops very quickly with the generations and instars increasing.展开更多
Zucchini yellow mosaic virus(ZYMV) was detected by RT-PCR from pumpkin(Cucurbita moschata) plant showing yellowing and mosaic symptom from Liaocheng,Shandong Province.The 3′-termial 1 684 bp genomic sequence covered ...Zucchini yellow mosaic virus(ZYMV) was detected by RT-PCR from pumpkin(Cucurbita moschata) plant showing yellowing and mosaic symptom from Liaocheng,Shandong Province.The 3′-termial 1 684 bp genomic sequence covered 633 bp of NIb encoding sequence,840 bp of cp gene and 211 bp of 3′-untranslated region of the isolate ZYMV-Liaocheng was determined.The cp gene of ZYMV-Liaocheng shared identities of 81.4%-98.8% and 89.4%-99.5% at nucleotide and amino acid levels,respectively,with other ZYMV sequences available in the GenBank.Phylogenetic analysis indicated that ZYMV could be clustered to 6 genotypes.ZYMV-Liaocheng belonged to genotype I,which contained isolates from Asia,Europe and America.Genotypes III and V were unique and contained only isolates from East Asia.The isolates from East Asia had the highest variability.展开更多
The sporulation conditions of Cercospora capsici were tested with physical and chemical methods.Conventional and particular media,ultraviolet radiation and different treatments on mycelia suspension were applied and s...The sporulation conditions of Cercospora capsici were tested with physical and chemical methods.Conventional and particular media,ultraviolet radiation and different treatments on mycelia suspension were applied and studied.It was found that C.capsici could produce conidia in the media of corn leaf powder agar and pepper leaf powder agar.The numbers of conidia produced in the two kinds of botanical media were 24 000 and 35 000 spores/mL,respectively.Compared with those isolated from the leaves,the conidia produced in the botanical media were more slender and pointed in morphology.展开更多
文摘Three hundred and one endophytic bacteria strains were isolated from healthy sugar beet plants in severely diseased plots in Changji County,Xinjiang Province.Three endophytic bacteria strains,1-5,4-1 and 4-3,showed relatively strong antagonistic against Cercospora beticola.Strain 1-5 was identified as Paenibacillus polymyxa,while strains 4-1 and 4-3 were as Bacillus flexus and Stenotrophomonas sp. by their morphological,physiological and biochemical characteristics.The results from several experiment trials showed that the endophytic bacteria could reduce the disease incidence of sugar beet.The control efficiency reached from 67.6% to 80.2%, indicating that biocontrol with endophytic bacteria was an alternative and potential method to control sugar beet fungi disease.
文摘The toxicity of insecticides to S.exigua different in generations and instars was tested by topical application. The results that the toxicity of alpha cypermethrin, methomyl, profenofos, and chlorfluazuron to 4th instar was decreased among second, fourth and sixth generations, and that of alpha cypermythrin, methomyl, profenofos, and chlorfluazuron to third, fourth and fifth instar of sixth generation was also decreased. These gave a viewpoint that the resistance develops very quickly with the generations and instars increasing.
文摘Zucchini yellow mosaic virus(ZYMV) was detected by RT-PCR from pumpkin(Cucurbita moschata) plant showing yellowing and mosaic symptom from Liaocheng,Shandong Province.The 3′-termial 1 684 bp genomic sequence covered 633 bp of NIb encoding sequence,840 bp of cp gene and 211 bp of 3′-untranslated region of the isolate ZYMV-Liaocheng was determined.The cp gene of ZYMV-Liaocheng shared identities of 81.4%-98.8% and 89.4%-99.5% at nucleotide and amino acid levels,respectively,with other ZYMV sequences available in the GenBank.Phylogenetic analysis indicated that ZYMV could be clustered to 6 genotypes.ZYMV-Liaocheng belonged to genotype I,which contained isolates from Asia,Europe and America.Genotypes III and V were unique and contained only isolates from East Asia.The isolates from East Asia had the highest variability.
文摘The sporulation conditions of Cercospora capsici were tested with physical and chemical methods.Conventional and particular media,ultraviolet radiation and different treatments on mycelia suspension were applied and studied.It was found that C.capsici could produce conidia in the media of corn leaf powder agar and pepper leaf powder agar.The numbers of conidia produced in the two kinds of botanical media were 24 000 and 35 000 spores/mL,respectively.Compared with those isolated from the leaves,the conidia produced in the botanical media were more slender and pointed in morphology.
