Population Genomics Related to Adaptation in Elite Oat Germplasm

Six hundred thirty five oat ( L.) lines and 4561 single-nucleotide polymorphism (SNP) loci were used to evaluate population structure, linkage disequilibrium (LD), and genotype–phenotype association with heading date. The first five principal components (PCs) accounted for 25.3% of genetic variation. Neither the eigenvalues of the first 25 PCs nor the cross-validation errors from = 1 to 20 model-based analyses suggested a structured population. However, the PC and = 2 model-based analyses supported clustering of lines on spring oat vs. southern United States origin, accounting for 16% of genetic variation ( < 0.0001). Single-locus -statistic () in the highest 1% of the distribution suggested linkage groups that may be differentiated between the two population subgroups. Population structure and kinship-corrected LD of = 0.10 was observed at an average pairwise distance of 0.44 cM (0.71 and 2.64 cM within spring and southern oat, respectively). On most linkage groups LD decay was slower within southern lines than within the spring lines. A notable exception was found on linkage group Mrg28, where LD decay was substantially slower in the spring subpopulation. It is speculated that this may be caused by a heterogeneous translocation event on this chromosome. Association with heading date was most consistent across location-years on linkage groups Mrg02, Mrg12, Mrg13, and Mrg24

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