Kartierung und züchterische Nutzung neuer Resistenzquellen gegen die pilzlichen Schaderreger <i>Pyrenophora teres</i> f. <i>teres</i> und <i>Puccinia hordei</i> der Gerste (<i>Hordeum vulgare</i>)

Abstract

The project aimed at the characterization and mapping of resistances against Puccinia hordei (Otth) and Pyrenophora teres f. teres in barley accessions MBR1012 and HHOR3073 and HHOR9484, respectively. Net blotch has become an important disease in the last decades and the leaf rust is one of the most important diseases affecting barley globally. Improving resistance against these pathogens is of prime importance in barley breeding, therefore. As a prerequisite for efficient screening for resistance against P. teres a so-called “summer hill trial” was established. Based on this design of trials and results obtained in 3 years at two locations with the DH-population Uschi x HHOR3073 and (Post x Viresa) x HHOR9484 heritability of net blotch resistance was estimated at h²=0.80 and h²=0.62, respectively and a continues variation to the reaction of net blotch infection was observed. In addition respective DH-lines were analysed in detached leaf assays using differentiating single conidial lines (SCL). Based on genetic maps comprising 705.7 cM (Uschi x HHOR3073) and 1,035.8 cM ((Post x Viresa) x HHOR9484) and corresponding phenotyping data, on four quantitative trait locus (QTL) on chromosomes 2H, 3H and 5H were identified in the population Uschi x HHOR3073. Furthermore, in the detached leaf test two QTL on chromosomes 3H and 7H, respectively and one majorgene on chromosome 7H were mapped. In the population (Post x Viresa) x HHOR9484 three QTL on chromosome 5H and one QTL on chromosome 7H were identified and in the detached leaf test one QTL on chromosome 3H and two QTL on chromosomes 4H and 5H were mapped. For resistance to the leaf rust isolate I-80 in the DH-population MBR1012 x Scarlett a segregation of 48 resistant : 43 susceptible plants (χ²_1:1 = 0.29) was observed indicating a monogenic inheritance of resistance. Using simple sequence repeats (SSR) and single nucleotide polymorphism (SNP) markers, the resistance gene in MBR1012 was mapped to the telomeric region of chromosome 1HS. The closest flanking markers for RphMBR1012 are located 0.8 cM distal (GBS546, GBMS187) and 6.0 cM proximal (GMS21). In the frame of these studies markers for major resistance genes and QTL against P. teres and P. hordei were identified suited to broaden the genetic base of resistance to these pathogens in barley breeding.