Proceedings of the XLV Italian Society of Agricultural Genetics - SIGA Annual Congress

Salsomaggiore Terme, Italy - 26/29 September, 2001

ISBN 88-900622-1-5

Poster Abstract

THE PCR-BASED MARKER MWG2018 LINKED TO THE RDG2A LEAF STRIPE RESISTANCE GENE IS A USEFUL TOOL FOR ASSESSING BARLEY RESISTANCE IN BREEDING PROGRAMS

ARRU L., DELOGU G., STANCA A.M., VALÈ G.

Istituto Sperimentale per la Cerealicoltura, Sezione di Fiorenzuola, Via S. Protaso 302, I-29017 Fiorenzuola d’Arda (PC), Italy

gp.vale@iol.it

barley, leaf stripe, MAS, resistance gene

The leaf stripe, caused by the fungus Pyrenophora graminea [anamorph Drechslera graminea (Rabenh. ex. Schlech.) Shoemaker], is an important seed-borne disease of barley. The objective of this study was to verify the reliability of a PCR-based marker (MWG2018) associated to the resistance gene Rdg2a, to assess the leaf stripe resistant phenotype in barley breeding programs. With this aim, a large number of barley cultivars and accessions were evaluated for their reaction against an highly virulent monoconidial isolate of the pathogen (the isolate Dg2) and genotyped for the allele of the molecular marker. Several resistant genotypes were identified and among them four demonstrated to possess the same allele of the cultivar Thibaut (the resistant parent of the original mapping population where Rdg2a was identified) at the marker locus. One of them, the cultivar Rebelle, is being used as source of leaf stripe resistance in winter barley breeding programs. In several resistant lines obtained from five crosses, in which Rebelle acted directly or indirectly as donor of the resistance, the allelic composition at the MWG2018 locus was verified; the results showed that the resistant phenotype of the lines was always associated with the resistant allele of the molecular marker, evidentiating the reliability of this marker to select for leaf stripe resistance. The MWG2018 PCR-based marker can therefore be proposed as a tool to assess the resistant phenotype.