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In Europe in the period 1994-1998, Helminthosporium leaf blotch disease was recorded in Austria, Belarus, Bulgaria, the Czech Republic, Estonia, Finland, Hungary, Italy, Norway, Poland, Russia and Yugoslavia. There was large variation in the quantitative reaction of oat (Avena sativa L.) genotypes to this disease, ranging from a disease resistance index (DRI) of 71 with cv. Kasadra to 16 with cv. Pan. Oat genotypes such as Kasadra, Pc 60, Pc 61, IL 86-6404, IL 86-1158, Rodney M, Pg 15, Cc 4761, Vermiou, Roxton, IL 85-6467, IL 85-2069, Pc 54-2, Orlando, OM 1387, Pc 59, KR 3813/73, IL 86-4189, Pc 68, Melys, OA 503-1, KR 288/73L/569, POB 1429/93, Pg l6, Pc 55 and Pc 56 had a consistently high disease resistance index. On the other hand, some had a low index which confirms the existence of pathogenic specialization of the causal fungus Pyrenophora avenae Ito et Kurib. Despite the absence of detailed analyses of the reaction of oats to the pathogen, it seems feasible to breed for resistance to the disease.

Control of SVBV relies completely on the use of virus-free planting material, that can be tested either by biological indexing or by molecular methods. A NASBA-based amplification was developed for the detection of SVBV. NASBA is a method based on the primer-dependent, specific amplification of RNA by concurrent activity of a special enzyme mix (AMV-reverse transcriptase, RNaseH, T7 RNA polymerase) at a single temperature (41°C). Specific and sensitive detection of the amplified sequence can be performed in the same tube using molecular beacons. Sensitivity of SVBV-NASBA was 102 molecules of in vitro RNA detected per reaction. Results of the NASBA-based detection of SVBV in indicator strawberry plants were well comparable to the results of PCR.

Two resistance phenotypes to P. brassicae have been found in A. thaliana. A first resistance phenotype has been detected to the isolate 'e₂' and is polygenically inherited. The second resistance to isolate 'e₃' is caused by the dominant resistance gene RPB1. By crossing no influence could be shown for salicylic acid, jasmonic acid and ethylene in the latter resistance reaction. The RPB1 locus was narrowed down to 71 kb on chromosome 1, where three pseudogenes and 13 coding sequences are located. Six of them showed cosegregation with RPB1. None of these sequences have similarities to identified resistance genes or other known genes. Ten coding sequences were expressed, but CDS9 was exclusively expressed in the resistant ecotype Tsu-0.

Two wheat powdery mildew differential sets were tested in the seedling stage in the 2001/2002 season using 192 monoisolates. The data of genotypes carrying the same Pm gene in different genetic backgrounds were compared. Both varieties with gene Pm8 (Salzmünde14/44 and Disponent) were infected by all the isolates. Less than 10% of the isolates gave different responses on varieties with genes Pm2 and Pm3c (6 and 16, respectively). It is doubtful whether the degree of infection of genotypes carrying genes Pm1, Pm4b, Pm5, Pm6 or Pm7 can be compared, while it is completely impossible to compare the data for varieties from the old and new sets carrying genes Pm3a, Pm3b and Pm4a.