Higher rust resistance and similar yield of oat landraces versus cultivars under high temperature and drought

Abstract

Oat crop is not particularly well adapted to hot and dry weather, as shown by a 3-fold yield reduction in Mediterranean compared to Northern regions. As a consequence, there is a need to identify more resilient oats adapted to current Mediterranean and future climate conditions. Here, we studied the performance of oat landraces under Mediterranean conditions, including the resistance to their most devastating disease, the crown rust. One hundred fortyone genetically characterized Spanish landraces were evaluated over two crop seasons at four contrasting locations in Spain and Egypt. Genotype-environment interactions were studied using heritability-adjusted genotype plus genotypeenvironment biplot analyses. The impact of climate variables on agronomic traits and the adaptation of particular landraces to environmental factors were inferred from non-metric multivariate scaling and canonical correspondence analyses. Results show an average oat landrace grain yield of 1500 kg/ha, which is similar to the mean yield of commercial varieties. Nonetheless, commercial varieties had 20% higher harvest index than landraces, which is explained by the higher biomass of landraces. Moreover, oat landraces showed high levels of rust resistance with mean values of the area under the disease curve of 2.58, which is approximately 25% lower than that of commercial varieties. Furthermore, several landraces carried a broad spectrum type of resistance which is expected to be more durable and efficient against different rust isolates.

Management Practices and Breeding History of Varieties Strongly Determine the Fine Genetic Structure of Crop Populations: A Case Study Based on European Wheat Populations

“…Similar events have been described in other studies [7][8][9]. In the case of oat, the impact of the disease was found to be 25% less for landraces than for modern varieties [10]. The causal relationship between genetic diversity and disease tolerance has been demonstrated for rice in China [11] showing a lower impact of plant disease for mixtures of varieties compared to single varieties.…”

Multi-Environmental Trials Reveal Genetic Plasticity of Oat Agronomic Traits Associated With Climate Variable Changes

“…Landraces are good reservoirs of favorable traits related to stress tolerance and resilience to the Mediterranean environment. For instance, oat landraces have demonstrated similar yield and higher rust resistance than oat cultivars under Mediterranean conditions ( Sánchez-Martín et al, 2017 ).…”

“…This is not straight-forward as they are highly affected by genotype × environment interactions. Indeed, oat landraces have shown higher variation among different environments than commercial cultivars ( Sánchez-Martín et al, 2017 ). The use of genetic markers may ease the selection of genotypes with particular desired characters, as it has been shown for several species during the last decades.…”

Adaptation of One-Flowered Vetch (Vicia articulata Hornem.) to Mediterranean Rain Fed Conditions

“…To determine stability and identify superior accessions across environments, the HA-GGE biplot analyses was conducted [9][10][11][12][13], comprising seasons 2009 to 2013, since it takes into consideration any heterogeneity among environments by giving weights to the test environments proportional to their root square heritability. As the environments have different heritabilities (data not shown) for the same trait, HA-GGE biplot is most appropriate for visual evaluation of the test environments and genotypes [9].…”