Preliminary Genetic Analysis of Resistance to Scald in Tunisian Barley

摘要

Leaf scald (Rhynchosporium secalis) of barley (Hordeum vulgare L.) is a serious disease in many barley-growing areas in Tunisia. A doubled-haploid barley population from a cross between the two-rowed cultivar 'Roho' and the six-rowed line '90' was evaluated for its resistance at the seedling stage to three isolates (Bousalem2, Krib5 and Teboursouk4) of R. secalis. The obtained frequency distributions suggest that resistance to Bousalem2 and Teboursouk4 isolates were polygenic whereas resistance to Krib5 isolate seems to be governed by two complementary genes. Heritability of the resistance to all isolates was relatively high (64%), although the genotype x isolate interaction effects were significant. Analysis of variance indicated that scald resistance was not dependent on row type. Three QTLs localised on chromosomes 3H, 4H and 6H were identified by the individual marker analysis with the Marker x Isolate interaction model.