Five years' results from a long-term field experiment on carbendazim resistance of Pseudocercosporella herpotrichoides (Fron) Deighton     

H. Fehrmann  J. Horsten  G. Siebrasse 《Crop Protection》1982,1(2):165-168

In a field monitoring experiment, winter wheat sown in large plots with or without applications of carbendazim was used to determine, during 5 years in succession, the development of carbendazim resistance in field populations of Pseudocercosporella herpotrichoides (Fron) Deighton, (Cercosporella herpotrichoides Fron). At the beginning of the experiment, one spore out of about 2·4 × 10⁹ was resistant. This figure increased at a linear rate that was highly statistically significant. Eventually, the frequency of carbendazim-resistant conidia was of the order of 10^?8. The differences in the frequency of resistant spores in the carbendazim-treated and in the untreated plots were highly significant, ranging from twofold to eightfold, depending on the year in question. In practice, there seems to be little danger from carbendazim resistance in the eyespot fungus if normal plant-protection recommendations are followed.  相似文献   

Pea symptomless virus,a newly recognized strain of red clover mottle virus     

K. Mahmood  J. Horsten  D. Peters 《European journal of plant pathology / European Foundation for Plant Pathology》1972,78(5):204-211

A virus contaminating a culture of pea enation mosaic virus was isolated and studied. The virus, tentatively named pea symptomless virus (PSV), was not aphid-borne but was readily transmitted by sap inoculation of Amaranthaceae, Chenopodiaceae and Leguminosae. Purified preparations of PSV contained isometric particles 26 nm in diameter, which sedimented as three components with sedimentation coefficients of 55, 94 and 118S, respectively, and contained ribonucleic acid with a molar base content of G 22%, A 26%, C 17%, U 34%.PSV is a member of the cowpea mosaic group of plant viruses, is closely related to red clover mottle broad bean stain, and pea green mottle viruses, and protects plants against infection with red clover mottle virus. PSV, the viruses of broad bean stain, red clover mottle and pea green mottle, and possibly MF-virus, probably constitute a subgroup of the cowpea mosaic virus group and may even considered to be members of a single virus species.Samenvatting Een virus dat als verontreiniging voorkwam in een cultuur van het erwte-enatiemozaïekvirus werd geïsoleerd en bestudeerd. Het virus dat voorlopig met de naam pea symptomless virus (PSV) wordt aangeduid, gaat met sap over en wordt niet door de bladluizenMyzus persicae enAcyrthosiphon pisum overgedragen.Plantesoorten uit de families der Amaranthaceae, Chenopodiaceae en Leguminosae (Tabel 1) zijn vatbaar voor dit virus. Gezuiverde preparaten van PSV bevatten isometrische deeltjes met een diameter van 26 nm (Fig. 1) en bestonden uit drie fracties (met sedimentatieconstanten van 118,94 en 55S (Fig. 2). Voor de basenverhouding in het RNZ werd 22% guanine, 26% adenine, 17% cytosine en 34% uracil (Tabel 2) gevonden.Het beschreven virus is serologisch zeer nauw verwant met het rode-klavervlekkenvirus (RCMV) en wat minder verwant met andere leden van de cowpea mosaic virus (CPMV) groep, zoals het broad bean stain virus (BBSV), en pea green mottle virus (PGMV). De symptomen die PSV en RCMV veroorzaakten werden vergeleken (Tabel 1); RCMV veroorzaakte in alle gevallen heviger symptomen.PSV is in staat om erwteplanten volledig tegen RCMV te beschermen indien de planten 9 dagen van te voren met eerstgenoemd virus geïnoculeerd waren. De auteurs concluderen uit hun werk dat PSV met BBSV, PGMV en RCMV een sub-groep binnen de CPMV-groep vormen, waartoe ook het MF-virus dat in Frankrijk is gevonden, zou kunnen worden gerekend.  相似文献   

Cloning and Characterization of Boar Epididymal Secretory Proteins by Homology to the Human   总被引：1，自引：0，他引：1  

B Schäfer  HH von  Horsten  JL Dacheux  W Holtz  C Kirchhoff 《Reproduction in domestic animals》2003,38(2):111-118

Northern blot analysis suggested that the boar epididymis produces closely related counterparts to human epididymal proteins HE1, HE3, HE4, HE5 and HE12. ‘Full‐length’ cloning by nucleic acid and amino acid sequence similarity was achieved by RT‐PCR methods in the case of the porcine counterparts of HE3 and HE4, while the homologues of HE5 and HE12, despite their cross‐hybridization during Northern blot analysis, have not yet been cloned. The two novel porcine cDNAs were derived from moderately abundant epididymal mRNAs that were 75 and 83% identical to HE3 and HE4 cDNAs, respectively. To emphasize their relationship to the corresponding HEs, they were named Se3 and Se4 cDNAs. Their open reading frames predicted small secretory proteins with 55% (Se3) and 76% (Se4) conserved amino acids. Monospecific antipeptide antibodies to HE secretory proteins identified He3‐ and HE12‐related proteins on Western blots of porcine epididymal fluid and semen. Both Northern and Western analyses indicated that the Se proteins were produced in a regionalized pattern and accumulated in the cauda fluid.  相似文献   

Spore germination and disease development after application of pycnidiospores ofAscochyta caulina toChenopodium album plants     

C. Kempenaar  P. J. F. M. Horsten  P. C. Scheepens 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(2):143-153

Ascochyta caulina is considered a potential mycoherbicide againstChenopodium album. Disease development ofC. album plants and plants of 14 other species after application of pycnidiospores ofA. caulina was studied in climate chamber experiments. The experiments were carried out to analyse disease development with time, and to recognize factors that may limit disease development. Two time courses of necrosis ofC. album plants were observed, (1) an increase of necrosis followed by a decline, and (2) an increase of necrosis up to completion with subsequent plant death. Courses of necrosis with time could be described by a non-monotonic, critically damped model when plants survived infection and by a monomolecular model when plants died from infection. Disease development was influenced by interactions between wetness period, density of the spore suspension applied, plant development stage at the time of spore application, and temperature. Disease was favoured by a long wetness period, a high number of spores applied, an early plant development stage at the time of spore application, and temperatures of 18 C and higher. Disease development was limited to plant species of the generaChenopodium, Atriplex andSpinacia with differences between the species. Pathogenicity differed significantly between threeA. caulina isolates tested. Variation in resistance between four source populations ofC. album was small. Prospects forA. caulina as a mycoherbicide are discussed.  相似文献