Resistance to Puccinia coronata f. sp. avenae in Avena magna, A. murphyi, and A. insularis

Abstract

Wild oat tetraploids of the section Pachycarpa have already been proven to be a rich source of useful genes but have largely been unexploited for Puccinia coronata resistance. In this study, accessions of Avena magna, A. murphyi, and A. insularis gathered from European and North American gene banks were evaluated at the seedling stage for crown rust reaction using the host–pathogen test and six highly diverse and virulent P. coronata isolates. Of the 92 Avena accessions analyzed, 58.7% were resistant to at least one crown rust race. In all, 37% of the tested accessions reacted nonuniformly, which indicated their heterogeneity. The highest level of resistance was observed in three of the accessions, one of which was verified by flow cytometry as being hexaploid and two of which were verified as being tetraploids. The infection profiles of 19 accessions corresponded to resistance determined by the genes Pc14, Pc39, Pc40, Pc48, Pc50, Pc54, Pc55, Pc61, Pc67, Pc68, Pc97, Pc101, or Pc104. The patterns of infection of the remaining resistant A. magna and A. murphyi accessions allowed us to postulate the presence of potentially novel crown rust resistance genes.

Puccinia coronata f. sp. avenae: a threat to global oat production

“…Several other wild oat species have been screened and used to identify new resistance genes (Aung et al ., ; Cabral and Park, ; Cabral et al ., ; Mitchell Fetch et al ., ; Rooney et al ., ). Recent sources of both race‐specific and APR include A. strigosa , A. glabrota , A. trichophylla , A. longiglumus , A. magna and A. murphyi (Cabral and Park, ; Sowa et al ., ; USDA‐ARS CDL, ); some of these sources originated from Moroccan and Israeli collections (Dinoor, ; Tan and Carson, ; Wahl, ). Carson () screened accessions of A. barbata from the Mediterranean region and found some additional sources of resistance for both seedling and adult stages, including a new type of ‘blotchy’ reaction in adult plants.…”

Identification of molecular markers for the Pc39 gene conferring resistance to crown rust in oat

“…Two hundred twenty seeds of F 2 'Celer'/STH9210 progeny were grown in plug trays filled with a universal substrate containing peat. Two hundred two progeny plants were phenotyped based on the host-pathogen test (Hsam et al 1997) conducted on the first leaves of 10-day-old seedlings as described in Sowa et al (2016). Crown rust resistance was tested using three P. coronata isolates 13.3/1; 94.1/4 and 107.2/3 ( Table 1).…”

“…Crown rust resistance was tested using three P. coronata isolates 13.3/1; 94.1/4 and 107.2/3 ( Table 1). The pathotypes were selected from a wide collection of single-pustule isolates derived from populations collected in Poland between the years 2010 and 2014 according to the method described by Sowa et al (2016). One leaf from each seedling was cut into three 3-cm-long fragments, and fragments were divided across separate 12-well culture plates with agar (0.6%) containing benzimidazole (3.4 mM).…”

The oat gene pools – review about the use of wild species in improving cultivated oat

“…A. murphyi could be a potential source of resistance to powdery mildew (Okoń et al, 2018), crown rust (Tan and Carson, 2013;Sowa et al, 2016), and some accessions also have high protein content and high groat oil content (Loskutov, 2005).…”

“…maroccana (formally known as A. magna) accessions have high contents of protein (to 30%), lysine and oil in grains. In addition, they are also resistant to powdery mildew (Okoń et al, 2018) and crown rust (Sowa et al, 2016), they have large grains (the weight of 1,000 grains reaches 35 g) and demonstrate highly productive tillering. The best-known example of gene introduction from the second gene pool into the cultivated oat variety is the CDC Bell line (Table 2) and a sister line, CDC Baler, forage oats developed at the Crop Development Centre, University of Saskatchewan (Rossnagel, 1999).…”