Template-Type: ReDIF-Article 1.0 Author-Name: Jaroslav Polák Author-Name: Jiřina Zieglerová Title: Distribution of Apple stem grooving virus in apple trees in the Czech Republic Abstract: From 1997 to 2000 the distribution of Apple stem grooving virus (ASGV) in selected intensive apple orchards was investigated at six sites in the Czech Republic. Detection of ASGV was by ELISA. The virus was found to be commonly distributed; it was detected in over 50 % of the tested trees. Some cultivars were infected up to 100 %, while several were found to be virus-free. A high incidence of infected trees appeared in both older (20 years) and younger (7 to 8 years) orchards. This emphasizes the necessity to initiate the certification of the health condition of nursery material according to the system recommended by the EPPO. Keywords: apple stem grooving virus, distribution, intensive orchards, apple trees Journal: Plant Protection Science Pages: 1-4 Volume: 37 Issue: 1 Year: 2001 DOI: 10.17221/8360-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/8360-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:37:y:2001:i:1:id:8360-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Gabriela Juhásová Author-Name: Helena Ivanová Title: Importance of the fungus Cytospora rubescens Fr. in relation to dieback of Sorbus aucuparia L. Abstract: During 1997-1999 the health condition of Sorbus aucuparia L. in the urban environment of the town Nitra was evaluated in relation to the type of usage or location of the trees, and occurrence, spread and harmfulness of the parasitic fungus Cytospora rubescens Fr. The developmental stages of the fungus in field and laboratory conditions, the virulence and growth rates of the mycelium isolated from trees of different usage or location was determined. The degree of damage by C. rubescens to S. aucuparia in Nitra was determined. No direct relation between degree of damage and the content of nine elements in the fungus C. rubescens was found. Keywords: Sorbus aucuparia, Cytospora rubescens, health condition, urban environment Journal: Plant Protection Science Pages: 5-9 Volume: 37 Issue: 1 Year: 2001 DOI: 10.17221/8361-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/8361-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:37:y:2001:i:1:id:8361-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Pavel Bartoš Author-Name: Alena Hanzalová Author-Name: Eva Stuchlíková Title: Wheat leaf rust races/pathotypes in the Czech Republic in 1999-2000 Abstract: In 1999-2000 virulence of the wheat leaf rust population was studied on Thatcher near isogenic lines (NILs) with Lr1, Lr2a, Lr2b, Lr2c, Lr3, Lr9, Lr10 (only in 2000), Lr11, Lr15, Lr17, Lr19, Lr21, Lr23, Lr24, Lr26 and Lr28. On these NILs 11 pathotypes were determined in 1999, and 18 in 2000. All rust samples were avirulent on Lr9, Lr19, Lr24 and Lr28. There was a relatively low frequency of virulence on Lr1, Lr2a and Lr2b. Most rust samples were virulent on Lr2c, Lr11, Lr15, Lr17, Lr21, Lr23 and Lr26. The identified pathotypes conformed with races 61SaBa, 77SaBa, 2SaBa, 12SaBa, 57SaBa, 6SaBa, 28SaBa, 61and 6. Races 61SaBa, 2SaBa and 77SaBa prevailed in 1999, races 61SaBa and 12SaBa were prevalent in 2000. Race 28SaBa was found for the first time. Data of the reactions to 15 leaf rust isolates of the recently registered winter wheat cultivars Niagara, Vlasta, Sulamit, Record, Ludwig, Apache, Semper, Drifter, Complet, Corsaire, Sepstra and Rialto are presented. Keywords: Puccinia persistens subsp. triticina, syn. Puccinia recondita f. sp. tritici, pathotypes, physiologic races (races), Lr-genes, wheat, registered cultivars, Czech Republic Journal: Plant Protection Science Pages: 10-16 Volume: 37 Issue: 1 Year: 2001 DOI: 10.17221/8362-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/8362-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:37:y:2001:i:1:id:8362-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Ľudovít Cagáň Author-Name: Marek Barta Title: Seasonal dynamics and entomophthoralean infection of the pea aphid, Acyrthosiphon pisum Harris Abstract: The seasonal dynamics of the pea aphid, Acyrthosiphon pisum Harris, and entomopathogenic fungi from the order Entomophthorales attacking the aphid were analysed in alfalfa and field pea crops during the growing seasons of 1998 and 1999 at Nitra-Malanta. In both years, pea aphid populations on pea showed a pattern with one peak, culminated at flowering and pod formation. The infestation level on alfalfa was low in both years. Entomopathogenic fungi attacking the pea aphid were identified as Erynia neoaphidis Remaudičre and Hennebert and Conidiobolus obscurus (Hall and Dunn) Remaudičre and Keller. Both pathogens infected the aphid on pea, but only E. neoaphidis was found in the alfalfa plots. Infected aphids were not found on alfalfa during 1999. The maximum levels of infected aphids on pea were 10.30% and 48.39% in 1998 and 1999, respectively. During both years alate aphids were more frequently attacked than apteral ones. Correlation coefficients indicated a positive relationship between the number of infected aphids and precipitation, but this relationship was weak or moderately strong. A strong correlation was found between the number of dead aphids and number of alate aphids counted 5 to 10 days earlier. Keywords: Erynia neoaphidis, Conidiobolus obscurus, Acyrthosiphon pisum, aphid pathogens Journal: Plant Protection Science Pages: 17-24 Volume: 37 Issue: 1 Year: 2001 DOI: 10.17221/8363-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/8363-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:37:y:2001:i:1:id:8363-PPS Template-Type: ReDIF-Article 1.0 Author-Name: Michaela Zemánková Author-Name: Aleš Lebeda Title: Fusarium species, their taxonomy, variability and significance in plant pathology - a review Abstract: Fusarium Link (1809) is an anamorph genus with worldwide distribution and a remarkable degree of biodiversity. Its species are common in soil and have been found on a very wide range of vascular plants. Some specialized species are parasitic on other fungi and or insects. In the system of fungi the genus Fusarium is classified in the class Hyphomycetes which belongs to the Deuteromycotina. Teleomorphs have been placed in the genera Nectria and Gibberella, order Hypocreales (Ascomycetes). The taxonomy of the genus Fusarium is not settled and the number of species and sections varies. A few recent classification systems of this genus exist. Fusarium spp. have mostly been studied in the context of their ability to cause diseases of many economically important crop plants. Some species produce mycotoxins and other metabolites that can be harmful to humans and livestock. There is a wide variability in pathogenicity, and in many Fusarium spp. various formae speciales (f.sp.) and physiological races are known. In this paper a description of the 14 most important soil and plant pathogenic Fusarium spp. is provided. Keywords: Fusarium spp., biodiversity, taxonomy and classification, morphology, in vitro growth characters, geographical distribution, ecology, toxins and other metabolites, pathogenicity, formae speciales and races Journal: Plant Protection Science Pages: 25-42 Volume: 37 Issue: 1 Year: 2001 DOI: 10.17221/8364-PPS File-URL: http://pps.agriculturejournals.cz/doi/10.17221/8364-PPS.html File-Format: text/html Handle: RePEc:caa:jnlpps:v:37:y:2001:i:1:id:8364-PPS