Template-Type: ReDIF-Article 1.0 Author-Name: Miroslav Glasa Author-Name: Daniela Benediková Author-Name: Žofia Glasová Author-Name: Ivan Hričovský Author-Name: Otakar Kůdela Title: Experimental evaluation of apricot genotypes for resistance to Plum pox virus Abstract: The reaction of 19 Slovak apricot cultivars and hybrids (breeding program of Research Breeding Station at Vesele) to infection by M isolates of plum pox virus (PPV-M) was evaluated. The genotypes were inoculated by grafting to naturally infected plum trees in the field and by chip-budding in the glasshouse. Monitoring of PPV infection was done over a 3 year period by visual inspection and DAS-ELISA. In the third year of evaluation the RT-PCR assay was also applied. The tested apricot genotypes differed in their reaction to PPV infection. Most of them developed mild or severe symptoms on leaves in the first year and/or next two consecutive years after artificial inoculation. The four Slovak apricot genotypes Veharda, Vemina, VS 15811 and VS 157/8 were resistant to PPV-M infection. Keywords: words:plum pox virus, Prunus armeniaca, inoculation, resistance Journal: Plant Protection Science Pages: 123-127 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9643-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9643-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9643-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Jaroslav Polák Author-Name: Milan Jokeš Title: Outbreak of a new phytoplasma disease of onion in the Czech Republic Abstract: In 1999, split vegetation tops in onions, cv. Stutgartska, grown in the surroundings of Prague, Bohemia, were observed. Such plants developed two or more bulbs from one originally planted. In addition, irregular and asymmetrical drying of the apical parts of outer skirts and in some cases scaling of the outer parts of divided bulbs occurred. Such divided bul bs suffered su bstantially higher damage during storage in winter; premature budding and grow the of individual parts was frequent. Further splitting of the vegetation tops into two to five parts and followed by premature budding was observed in individual parts of divided bulbs. Ultrathin sections were prepared from roots and leaves of divided bulbs. Phytoplasma bodies were found in tissues of both roots and leaves. Such bodies were not found in roots and leaves of healthy looking and undivided bulbs. Keywords: phytoplasma disease, onion, vegetation top splitting, ultrathin section, roots, electron microscopy, phytoplasma bodies Journal: Plant Protection Science Pages: 128-131 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9644-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9644-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9644-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Pavel Vejl Author-Name: Sylvya Skupinová Author-Name: Ivana Polišenská Author-Name: Marie Váňová Title: Distinguishing isolates of cereal stem disease pathogens of the genus Tapesia from isolates of Fusarium and Rhizoctonia using the RAPD method Abstract: The RAPD method (Random Amplification of Polymorphous DNA) was used to distinguish Tapesia acufonnis and T. yallundae isolates from other pathogens of wheat stem base diseases (Fusarium avenaceum, F. culmorum, F. nivale, Rhizoctonia cerealis and R. so/ani).Isolates of the fungi originated from infected wheat plants (Triticum aestivum L.) collected at various locations in the Czech Republic. Three decameric oligonucleotide-primers were selected as producing genotype-specific RAPD products. These markers distinguish all isolates of the above taxons. The intra-species genetic variability of these species also was studied. The values of Dice's coefficients of similarity suggest that isolates of Tapesia yallundae showed a higher degree of intra-species variability than those ofT acufonnis. A high degree of intra-species variability was identified also in Fusarium avenaceum. Keywords: DNA, polymerase chain reaction (PCR), random amplified polymorphic DNA (RAPD), markers, fingerprinting, genetic similarity Journal: Plant Protection Science Pages: 132-140 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9645-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9645-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9645-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Lubomír Věchet Title: Leaf rust occurrence in European winter wheat varieties and breeding lines Abstract: In 1998 and 1999, 52 winter wheat varieties and breeding lines originated from ten European countries were tested for their reaction to leaf rust, the inoculum was a mixture of races UN3-61SaBa and UN13-77SaBa. Twenty six varieties and lines stayed in the same group (susceptible, moderately susceptible, moderate, moderately resista nt) in both years, with the majority being moderately resistant. Of the Czech varieties Asta, Rexia and VIada stayed in the same group in both years. Some varieties moved from one group in 1998 to another in 1999. Some of the moderately resistant varieties and lines (Hereward, WW2568, P8634, Trakos, WW251 0, Asset, WW2564) showed a hypersensitive reaction (chlorosis, necrosis). There were differences in the number of diseased plants between groups with a different reaction to leaf rust mainly at the beginning of the epidemic Keywords: Puccinia recondita f. sp. triitici, winter wheat, cluster analysis, resistance Journal: Plant Protection Science Pages: 141-146 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9646-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9646-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9646-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Ľudovít Cagáň Author-Name: Grayzna Sobota Author-Name: Beata Gabryš Author-Name: Czeslaw Kania Title: Voltinism of the European corn borer, Ostrinia nubilalis Hbn., in Poland Abstract: From 1992 to 1996 the voltinism of the European com borer, Ostrinia nubilalis Hbn., was investigated in Poland. During the study, over 6000 larvae were collected in maize stalks in autumn. In 1994, pupal cases were observed in stalks. This indicated the development of second generation adults of the pest. Pupal cases were not found in other years of the study. The difference between 1994 and the other years was found when the degree-days accumulation at base 10°C was calculated for the periods between July 1 and July 19 (daylight 15 hrs 58 min), or July 29 (daylight 15 hrs 32 min). These values were highest in 1994 and reached 246.5°C, or 414.0°C respectively. The results indicate that degree-days accumulation during the whole year is not responsible for the development of the second generation. It appears that high temperatures in July (not only at the beginning, but also at the end) influenced the development of the second generation of 0. nubilalis in Poland. Average July daily temperatures in 1994 were extremely high (24.5°C). Such temperatures can allow a small partial development of the second generation of O. nubilalis at a relatively cold location like Wroclaw in Poland with a standard annual mean temperature of 8.3°C. Keywords: Ostrinia nubilalis, European com borer, voltinism, diapause, photoperiod Journal: Plant Protection Science Pages: 147-149 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9648-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9648-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9648-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Josef Šedivý Author-Name: Vladimír Řehák Title: Outbreak of mirid bugs (Heteroptera: Miridae) on hops Abstract: Outbreaks of mirid-bugs on hop in Czech hop region recurred in 1875, I 928/29, 1947/48 and 1998/99. The spectrum and importance of specific harmful mirid species varied with the type of hop-garden. Calocoris fulvomaculatus was a dominant species in pole hop-gardens. Lygus rugulipennis was a dominant pest in trellises in 1998/99, when it locally damaged more than 50% of bines. Mirid-bugs migrate to hops at temperatures over l0°C, and stay there over the growing season. Bine tops are damaged by sucking, drying back later. Bines that grow from under the sites of injury are distorted and cease twining. This damage is caused before and after the training, up to 2.5 m of the bines height. An economic threshold is at I0% of damaged bine tops and more in the period after training. Years with warm, dry autumn, mild winter and warm, dry spring provide favourable conditions for outbreaks of the mirid-bugs and their spring activities. Keywords: hop, mirid-bugs, monitoring, damage, economic threshold, weather Journal: Plant Protection Science Pages: 150-155 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9647-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9647-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9647-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Aleš Lebeda Author-Name: Barbora Mieslerová Title: Case study of host-pathogen interaction: tomato (Lycopersicon spp.)-tomato powdery mildew (Oidium lycopersici) - a review Abstract: The present paper tries to demonstrate progress and gap of knowledge in plant pathology through the tomato - tomato powdery mildew host-pathogen interaction as a model. Tomato powdery mildew (Oidium lycopersici) has caused serious damages on glasshouse tomato (Lycopersicon esculentum) crops during the last approximately 15 years. Although the absence of tcleomorph stage did not allow exact taxonomic classification of the pathogen, comparative morphological studies using light and scanning electron microscopy revealed that Oidium lycopersici might be included to the Erysiphe sect. Erysiphe (close to Erysiphe aqui­ legiae var. ranunculi). Effective resistance sources to 0. lycopersici were found mainly in wi ld Lycopersicon hirsutum and L. penne/lii (confirmed by testing with four different 0. lycopersici isolates). Available information on the pathogenic variability of 0. lycopersici is given; host range experiments revealed considerable differences in abi lity of different 0. lycopersici isolates to infect cucumber and tobacco. postulating existence of different pathotypcs lformae specialist of pathogen. Similarly, some Lycopersicon spp. genotypes showed remarkable differential reactions with pathogen isolates, indicating existence of different pathogen races. Information regarding recently detected mechanisms and basis of resistance in Lycopersicon spp. are also men­ tioned. However, more research based on classical, biochemical and molecular approaches is also needed. Keywords: Lycopersicon spp., Oidium lycopersici, distribution, taxonomical position, host range, pathogenic variability, re­sistance sources, basis of resistance, mechanisms of resistance Journal: Plant Protection Science Pages: 156-162 Volume: 36 Issue: 4 Year: 2000 DOI: 10.17221/9650-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/9650-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:36:y:2000:i:4:id:9650-PPS