Molecular identification of a new powdery mildew resistance gene Pm41 on chromosome 3BL derived from wild emmer (Triticum turgidum var. dicoccoides)

Abstract

Powdery mildew caused by Blumeria graminis f. sp. tritici is an important wheat disease in China and other parts of the world. Wild emmer (Triticum turgidum var. dicoccoides) is the immediate progenitor of cultivated tetraploid and hexaploid wheats and thus an important resource for wheat improvement. Wild emmer accession IW2 collected from Mount Hermon, Israel, is highly resistant to powdery mildew at the seedling and adult plant stages. Genetic analysis using an F(2) segregating population and F(2:3) families, derived from a cross between susceptible durum cultivar Langdon and wild emmer accession IW2, indicated that a single dominant gene was responsible for the resistance of IW2. Bulked segregant and molecular marker analyses detected that six polymorphic SSR, one ISBP, and three EST-STS markers on chromosome 3BL bin 0.63-1.00 were linked to the resistance gene. Allelic variations of resistance-linked EST-STS marker BE489472 revealed that the allele was present only in wild emmer but absent in common wheat. Segregation distortion was observed for the powdery mildew resistance allele and its linked SSR markers with preferential transmission of Langdon alleles over IW2 alleles. The resistance gene was introgressed into common wheat by backcrossing and marker-assisted selection. Since no designated powdery mildew resistance gene has been found on chromosome 3BL, the resistance gene derived from wild emmer accession IW2 appears to be new one and was consequently designated Pm41.

Identification of Pm24, Pm35 and Pm37 in thirteen Egyptian bread wheat cultivars using SSR markers

“…Development of resistant germplasm to powdery mildew is based on interspecific hybridization and backcrossing (Murphy;Navarro;Leath, 2002;Navarro et EMARA, H. M. et al al., 2000). To date, 61 powdery mildew resistance genes, mapped to 43 loci (McIntosh;Yamazaki;Dubcovsky, 2008;He et al, 2009;Hua et al, 2009;Li;Fang;Zhang, 2009;Luo et al, 2009) have been identified and formally catalogued in wheat. However, some of the genes, derived from wild relatives, are difficult to use in wheat breeding because of linkage drag (Hospital, 2001).…”

High-density mapping and marker development for the powdery mildew resistance gene PmAS846 derived from wild emmer wheat (Triticum turgidum var. dicoccoides)

“…dicoccoides, AABB, 2n = 28) is a valuable source of resistance to pathogens, and genes transferred from this species included powdery mildew resistance genes Pm16, Pm26, Pm30, Pm36, Pm41, and pm42, which were transferred to wheat chromosomes 5BS, 2BS, 5BS, 5BL, 3BL and 2BS, respectively (Reader and Miller 1991;Chen et al 2005;Rong et al 2000;Liu et al 2002;Blanco et al 2008;Li et al 2009;Hua et al 2009). There is also potential, largely untapped of the rich genetic resource in wild emmer, for disease resistance, pest tolerance and various abiotic stresses (Xie and Nevo 2008).…”

Molecular and Cytogenetic Characterization of a Powdery Mildew-Resistant Wheat-<b><i>Aegilops mutica</i></b> Partial Amphiploid and Addition Line

“…Among these genes, 16 originate from alien species . Nevertheless, many wheat cultivars seem to have the same few Pm genes, such as Pm2 , Pm4b , Pm5 , Pm6, and Pm8 [Zeller et al, 1993;McIntosh et al, 1998], providing little protection against the contemporary pathogen populations [Limpert et al, 1987;Li et al, 2009]. Some other effective resistance genes, such as Pm1c , Pm12 , Pm13 , Pm16, and Mlxbd , cannot be widely used in breeding programs due to their poor agronomic traits associated with either alien chromosome segments or unadapted genetic backgrounds [Duan et al, 1998;Qiu and Zhang, 2004].…”