Genetic Diversity and Population Structure Among Oat Cultivars and Landraces

In this study, genetic diversity among 177 oat (Avena sativa L.) accessions including both white and red oat landraces and 36 commercial cultivars was studied for simple sequence repeat (SSR) loci. Thirty-one genomic and expressed sequence tags (EST)-derived primer pairs were selected according to high polymorphism from an initial 66 SSR batch. Markers revealed a high level of polymorphism, detecting a total of 454 alleles. The average gene diversity for the whole sample was 0.29. Genetic similarity, calculated using the Dice coefficient, was used for cluster analysis, and principal component analysis was also applied. In addition, population structure using a Bayesian clustering approach identified discrete subpopulation based on allele frequency and showed similar clustering of oat genotypes in four groups. Accessions could be classified into four main clusters that clearly separated the commercial cultivars, the red oat landraces and two clusters of white oat landraces. Cultivars showed less diversity than the landraces indicating a reduction of genetic diversity during breeding, whereas white oat landraces showed higher diversity than red ones. The average polymorphic information content of 0.80 for the SSR loci indicated the usefulness of many of the SSR for genotype identification. In particular, two markers, MAMA5 and AM04, with a total of 50 alleles and a high discrimination power (>0.90), were sufficient to discriminate among all commercial cultivars studied highlighting their potential use for variety identification. © 2013 Springer Science+Business Media New York.This work was supported by the Spanish Ministry of Economy and Competitiveness [AGL2010-15936/AGR], the European Social and Regional Development Funds, a JAE PreDoc fellowship from CSIC to [GMB], a JAE Postdoctoral Fellowship from CSIC to [NR], and a FPU fellowship from the Spanish Ministry of Science and Innovation to [JSM].Peer Reviewe

Structural patterns and genetic diversity among oat (Avena) landraces assessed by microsatellite markers and morphological analysis

As a counterweight to genetic erosion, landraces could become important germplasm resources for breeding. In the present study the genetic diversity of 62 Greek and Eastern European oat accessions (seven cultivars and 55 common and red oat landraces collected from 1904 to 1960) was studied using simple sequence repeats and 31 morphological descriptors. High levels of polymorphism were detected and 209 distinctive alleles were identified; on average 14.65 alleles per primer. Both, the principal component analysis derived from the morphological data, and the unweighted pair group method with arithmetic mean from the molecular analysis clustered the oat genotypes according to their type (common and red oats). In addition, the analysis of molecular variation showed that there were noteworthy differences within designated geographic regions. Moreover, a more discrete subpopulation structure was identified based on allele frequency using a Bayesian clustering approach. A clear distinction was evident among the red and common oats suggesting that they should be considered as separate species

Genomic Approaches for Climate Resilience Breeding in Oats

Editors: Chittaranjan Kole.Oat (Avena sativa L.), ranking sixth in world cereal production, is primarily produced as a multipurpose crop for grain, pasture, and forage or as a rotation crop in many parts of the world. Recent research has elevated its potential dietary value for human nutrition and health care. Oats are well adapted to a wide range of soil types and can perform on acid soils. World oat production is concentrated between latitudes 35–65º N, and 20–46º S. Avena genomes are large and complex, in the range of 4.12–12.6 Gb. Oat productivity is affected by many diseases, although crown rust (Puccinia coronate f. sp. avenae) and stem rust (Puccinia graminis f. sp. avenae) are the key diseases worldwide. The focus of this chapter is to review the major developments and their impacts on oat breeding, especially on the challenges posed by climate or environmental changes (biotic and abiotic stresses mainly) for oat cultivation. Next-generation breeding tools will help to develop approaches to genetically improve and manipulate oat which would aid significantly in oat enhancement efforts. Although, oat biotechnology has been advanced at a similar pace as the rest of cereals, it lags still behind. More genomic tools, from genomic assisted breeding to genome editing tools are needed to improve the resources to improve oats under climate change in the next few decades