Template-Type: ReDIF-Article 1.0 Author-Name: editors Title: Index of Volume 41 Journal: Plant Protection Science Pages: I-VI Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2753-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2753-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2753-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Arie Rosner Author-Workplace-Name: Virology Department, Institute of Plant Protection, ARO, Volcani Center, Bet Dagan, Israel Author-Name: Ludmila Maslenin Author-Workplace-Name: Virology Department, Institute of Plant Protection, ARO, Volcani Center, Bet Dagan, Israel Title: Interference in PCR: Transcription amplifications of mixed PVY isolates Abstract: Interference in PCR and transcription amplifications by mixed virus templates is described. The yields of PCR amplification of closely related PVY isolates in a mixture were lower than those of the separate amplification of each individual virus strain, i.e. the two virus templates mutually interfered in their amplification process. When PCR products of mixed PVY isolates served as templates for transcription, RNA synthesis was also inhibited. This interference could be avoided by applying strain-specific primers in the separate amplification of each target sequence in the mixture. The use of strain-specific primers in PCR amplification of a mixed virus infection thus enabled detection of each virus isolate without interference. Keywords: potato virus Y, rSSCP, RFLP, mixed infection, interference, conformation polymorphism, PCR Journal: Plant Protection Science Pages: 125-131 Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2750-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2750-PPS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pps-200504-0002.txt Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2750-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Tomáš Nečas Author-Workplace-Name: Department of Pomology, Faculty of Horticulture, Mendel University of Agriculture and Forestry Brno, Lednice, Czech Republic Author-Name: Boris Krška Author-Workplace-Name: Department of Pomology, Faculty of Horticulture, Mendel University of Agriculture and Forestry Brno, Lednice, Czech Republic Title: Detection of phytoplasma ESFY in apricot trees using phloem and petioles Abstract: ESFY phytoplasma (European stone fruit yellows phytoplasma) is nowadays one of the most important plant diseases, especially on apricots and peaches, and it belongs to the list of organisms for which quarantine is required in the Czech Republic. The aim of this study was to determine the best period for tissue extraction and the best technique for ESFY detection. It was also to investigate the possibility of isolating DNA for use in ESFY detection from the leaf-stalks of randomly chosen symptomatic and asymptomatic apricot trees. Results of the amplification of DNA extracted from leaf-stalk and phloem sampled from 2-year old woody shoots during the years 2003 and 2004 were statistically analysed and compared, and visible disease symptoms were simultaneously evaluated and compared to the results of molecular detection. DNA isolation from leaf-stalks can be considered as less significant and reliable than isolation from phloem sampled from 2-year old woody shoots. Keywords: ESFY, apricot, PCR, detectability, symptoms Journal: Plant Protection Science Pages: 132-140 Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2751-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2751-PPS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pps-200504-0003.txt Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2751-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Josef Patzak Author-Workplace-Name: Hop Research Institute Co., Ltd., Žatec, Czech Republic Title: PCR detection of Pseudoperonospora humuli and Podosphaera macularis in Humulus lupulus Abstract: Hop downy mildew (Pseudoperonospora humuli) and hop powdery mildew (Podosphaera macularis) are the most important pathogens of hop (Humulus lupulus). The early detection and identification of these pathogens are often made difficult by symptomless or combined infection with another pathogens. Molecular analysis of internal transcribed spacer (ITS) regions of rDNA is a novel and very effective method of species determination. Therefore, specific PCR assays were developed to detect the pathogens Pseudoperonospora humuli and Podosphaera macularis in naturally infected hop plants. The specific PCR primer combinations P1 + P2 and S1 + S2 amplified specific fragments from Pseudoperonospora humuli and Podosphaera macularis, respectively, and did not cross-react with hop DNA nor with DNA from other fungi. PCR primer combinations R1 + R2 and R3 + R4 could be used in multiplex PCR detection of Pseudoperonospora humuli, Podosphaera macularis, Verticillium albo-atrum and Fusarium sambucinum. Phylogenetic relationships were inferred for 42 species of the Erysiphales from nuclear rDNA (ITS1, 5.8S, ITS2). The molecular characterisation and phylogenetic analyses confirmed the species identification of hop powdery mildew. The PCR assays used in this study proved to be accurate and sensitive for detection, identification, classification and disease-monitoring of the major hop pathogens. Keywords: hop powdery mildew, hop downy mildew, internal transcribed spacers (ITS), PCR detection, phylogenetic analysis Journal: Plant Protection Science Pages: 141-149 Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2749-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2749-PPS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pps-200504-0004.txt Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2749-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Josef Šedivý Author-Workplace-Name: Department of Entomology, Division of Plant Health, Research Institute of Crop Production, Prague-Ruzyně, Czech Republic Author-Name: Petr Born Author-Workplace-Name: State Phytosanitary Administration, Rakovník, Czech Republic Author-Name: Josef Vostřel Author-Workplace-Name: Hop Research Institute, Co., Ltd., Žatec, Czech Republic Title: Harmful occurrence of Rosy rustic moth (Hydraecia micacea) (Noctuidae: Lepidoptera) on hop in the Czech Republic Abstract: The Rosy rustic moth (Hydraecia micacea) has been a pest of hop in Czech hop regions for a long time. It causes most severe damages in hop gardens infested by quackgrass (Elytrigia repens) on waterlogged areas. Larvae emerge from the second half of April to the middle of May. The sum of effective temperatures (SET) necessary for hatching larvae has been determined to be 78.6C over a 4-year average. Young larvae first feed on leaves of quackgrass, and later move to hop plants where they feed inside the shoots and rootstocks. Occurrence and damage are most frequent at the edges of hop gardens and in places with anchorages between two hop gardens. The ichneumonid wasp Ichneumon sarcitorius and the fly Lidella thompsoni are the most common parasitoids of this pest. Numbers of males caught in pheromone traps were very low. More males were trapped near hop gardens typical for repeated harmful occurrence of the rosy rustic moth. Females trapped in a light trap from the second half of August to the last decade of September had already full-developed eggs in their ovaries. Keywords: hatching of caterpillars, weeds, parasitoids, harmfulness, monitoring, antagonist Journal: Plant Protection Science Pages: 150-157 Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2748-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2748-PPS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pps-200504-0005.txt Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2748-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Elizabeth Agbenu Egwurube Author-Workplace-Name: Department of Crop Protection, Faculty of Agriculture, Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria Author-Name: Michael Ogunleke Ogunlana Author-Workplace-Name: Department of Crop Protection, Faculty of Agriculture, Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria Author-Name: Michael Chidozie Dike Author-Workplace-Name: Department of Crop Protection, Faculty of Agriculture, Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria Author-Name: Isa Onu Author-Workplace-Name: Department of Crop Protection, Faculty of Agriculture, Institute for Agricultural Research, Ahmadu Bello University, Zaria, Nigeria Title: Pest status of the leafhopper Empoasca dolichi Paoli on groundnut (Arachis hypogaea L.) in the Zaria area of northern Nigeria Abstract: Population studies and tests on the relationship between density and damage were conducted in 1999 to 2001 to determine the pest status of Empoasca dolichi on groundnut (Arachis hypogaea L.) in the Zaria area of northern Nigeria. Analyses showed that Empoasca numbers varied significantly from one year to another, and within each year the numbers of leafhoppers observed at the different growth stages of the plant were significantly different (P = 0.01). There was an inverse and highly significant relationship between the mean kernel yield and the Empoasca damage at the different growth stages of the plant. When natural population densities were plotted against economic injury level (EIL), the densities did not reach the EIL throughout the groundnut growing seasons. The insect was thus not an economic pest on groundnut in Zaria during the period of the study. Keywords: pest status, Empoasca dolichi Paoli, groundnut, Arachis hypogaea L Journal: Plant Protection Science Pages: 158-164 Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2754-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2754-PPS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pps-200504-0006.txt Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2754-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Václav Kůdela Author-Workplace-Name: Department of Bacteriology, Division of Plant Medicine, Research Institute of Crop Production, Prague-Ruzyně, Czech Republic Author-Name: Bohumila Voženílková Author-Workplace-Name: Faculty of Agriculture, University of South Bohemia, České Budějovice, Czech Republic Author-Name: Radka Krejzarová Author-Workplace-Name: Department of Bacteriology, Division of Plant Medicine, Research Institute of Crop Production, Prague-Ruzyně, Czech Republic Author-Name: Václav Krejzar Author-Workplace-Name: Department of Bacteriology, Division of Plant Medicine, Research Institute of Crop Production, Prague-Ruzyně, Czech Republic Author-Name: Michal Janouch Author-Workplace-Name: Solar and Ozone Observatory, Czech Hydrometeorological Institute, Hradec Králové, Czech Republic Title: Destruction of chlorophyll in emerging seedlings of spring barley associated with environmental stresses Abstract: An unusual disorder occurred on spring barley seedlings in southern and central Bohemia in April 2005. Affected seedlings showed conspicuous bleached or straw-coloured areas on tips of the first leaves. There were very sharp, distinct, horizontal boundaries between the green basal and discoloured tip parts of the leaves. It was remarkable that these boundaries were at the same position on all affected first leaves of seedlings from the same field. Affected seedlings were randomly distributed in the fields, and their incidence ranged from about 20 to 70% according to location. Based on meteorological data it can be concluded that the colour abnormality in emerging seedlings was associated with specific environmental stresses, being effective in certain chronological order on sensitive plant tissues during the period from 6 to 8 days after seeding. These stresses include frosty mornings followed by clear days with high solar radiation with a high UV Index. Keywords: Hordeum vulgare L., colour abnormality, environmental stresses, UV radiation, Czech Republic Journal: Plant Protection Science Pages: 165-170 Volume: 41 Issue: 4 Year: 2005 DOI: 10.17221/2752-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/2752-PPS.html File-Format: text/html X-File-Ref: http://agriculturejournals.cz/RePEc/caa/references/pps-200504-0007.txt Handle: RePEc:caa:jnlpps:v:41:y:2005:i:4:id:2752-PPS