Screening the Spanish Barley Core Collection for disease resistance

26 Pag., 6 Tabl. The definitive version is available at: www3.interscience.wiley.comThe Spanish Barley Core Collection comprises 159 landrace-derived inbred lines and 16 cultivars adapted to Southern European conditions. The collection was screened for resistance to powdery mildew (Blumeria graminis), scald (Rhynchosporium secalis), leaf rust (Puccinia hordei), net blotch (Pyrenophora teres f. teres), Barley yellow dwarf virus (BYDV) and Barley mild mosaic virus (BaMMV). Resistance to powdery mildew was outstanding, with 58 lines presenting mean overall resistance, among them seven landrace-derived lines resistant to all seven isolates tested. About 26% of the Spanish lines were resistant to scald. Resistance to leaf rust and to net blotch was scarce, though a few accessions showed resistance levels as good as the checks. Thirteen accessions (12 Spanish) were totally resistant to BaMMV and c. 20% of accessions showed moderate tolerance to BYDV. Landrace-derived lines from the Mediterranean Coast and Southern regions of Spain were the most resistant to powdery mildew and leaf rust, but the most susceptible to viruses. Potential sources of resistance might be preserved in some accessions subjected to selective pressure in the region of origin.This study was funded by projects RTA01-088-C3, granted by the INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentación), of the Spanish Ministry of Science and Technology, projects AGL2004-05311/AGR, AGL2007-63625, all of them co-funded by the European Regional Development Fund and the Bavarian Ministry of Agriculture and Forest/Bayerisches Staatsministerium für Landwirtschaft und Forsten.Peer reviewe

The impact of global warming on plant diseases and insect vectors in Sweden

Cold winters and geographic isolation have hitherto protected the Nordic countries from many plant pathogens and insect pests, leading to a comparatively low input of pesticides. The changing climate is projected to lead to a greater rise in temperature in this region, compared to the global mean. In Scandinavia, a milder and more humid climate implies extended growing seasons and possibilities to introduce new crops, but also opportunities for crop pests and pathogens to thrive in the absence of long cold periods. Increased temperatures, changed precipitation patterns and new cultivation practices may lead to a dramatic change in crop health. Examples of diseases and insect pest problems predicted to increase in incidence and severity due to global warming are discussed

Genomics-based high-resolution mapping of the BaMMV/BaYMV resistance gene <em>rym11</em> in barley (<em>Hordeum vulgare</em> L.).

Soil-borne barley yellow mosaic virus disease, caused by different strains of Barley yellow mosaic virus (BaYMV) and Barley mild mosaic virus (BaMMV), is one of the most important diseases of winter barley (Hordeum vulgare L.) in Europe and East Asia. The recessive resistance gene rym11 located in the centromeric region of chromosome 4HL is effective against all so far known strains of BaMMV and BaYMV in Germany. In order to isolate this gene, a high-resolution mapping population (10,204 meiotic events) has been constructed. F-2 plants were screened with co-dominant flanking markers and segmental recombinant inbred lines (RILs) were tested for resistance to BaMMV under growth chamber and field conditions. Tightly linked markers were developed by exploiting (1) publicly available barley EST sequences, (2) employing barley synteny to rice, Brachypodium distachyon and sorghum and (3) using next-generation sequencing data of barley. Using this approach, the genetic interval was efficiently narrowed down from the initial 10.72 % recombination to 0.074 % recombination. A marker co-segregating with rym11 was developed providing the basis for gene isolation and efficient marker-assisted selection