Molecular mapping of Pc68, a crown rust resistance gene in Avena sativa

Abstract

Crown rust, which is caused by Puccinia coronata f. sp. avenae, P. Syd. & Syd., is the most destructive disease of cultivated oats (Avena sativa L.) throughout the world. Resistance to the disease that is based on a single gene is often short-lived because of the extremely great genetic diversity of P. coronata, which suggests that there is a need to develop oat cultivars with several resistance genes. This study aimed to identify amplified fragment length polymorphism AFLP markers that are linked to the major resistance gene, Pc68, and to amplify the F 6 genetic map from Pc68/5*Starter 9 UFRGS8. Seventy-eight markers with normal segregation were discovered and distributed in 12 linkage groups. The map covered 409.4 cM of the Avena sativa genome. Two AFLP markers were linked in repulsion to Pc68: U8PM22 and U8PM25, which flank the gene at 18.60 and 18.83 centiMorgans (cM), respectively. The marker U8PM25 is located in the linkage group 4_12 in the Kanota 9 Ogle reference oat population. These markers should be useful for transferring Pc68 to genotypes with good agronomic characteristics and for pyramiding crown rust resistance genes.

Screening Wild Oat Accessions from Morocco for Resistance to Puccinia coronata

“…Breeders then turned to exotic sources of resistance in wild Avena spp. The hexaploid wild animated oat, A. sterilis, was first used as a source because of its crossability with cultivated oat (8). However, the initial euphoria caused by an apparent abundance of new Pc genes soon turned to disappointment.…”

Chromosome-anchored QTL conferring aluminum tolerance in hexaploid oat

“…This number is consistent with results from Oliver et al (2013) where 16 % of the SNP loci interrogated by the Illumina GoldenGate assay were polymorphic across six different mapping populations on average. Low polymorphism is a common characteristic to species with large genomes (Kulcheski et al 2010;Li et al 2000;Yu and Herrmann 2006). It has been suggested that the low genetic polymorphism found in crops such as oat and wheat is due to the evolution of the species (Bryan et al 1999).…”

Identification and genetic characterisation of adult plant resistance to crown rust in diploid and tetraploid accessions of Avena

“…Previous research has identified seedling resistance genes that protect wild and cultivated oats against Pca, and at least 96 such genes have been characterised and given Pc designations (CDL, 2006; Kulcheski et al , 2010). A majority of the Pc resistance genes described to date have been derived from genotypes of hexaploid and diploid oat species, and have proven to be non‐durable.…”