Association mapping of sponge cake volume in U.S. Pacific Northwest elite soft white wheat (Triticum aestivum L.)

Abstract Sponge cake quality is an essential end-use trait for U.S. Pacific Northwest (PNW) soft white (SW) wheat, primarily measured by the volume of a cake. The baking of each cake is relatively expensive, labor intensive, and requires a substantial amount of flour. As a result, sponge cake baking is conducted in later generations on a limited number of breeding lines. Insight into the genetic architecture of sponge cake volume would help provide an alternative to cake baking. Here we describe the analysis of 387 wheat genotypes spanning 27 crop years with a total of 685 environments for sponge cake volume. Genotyping by sequencing was used to generate molecular markers in wheat representing elite germplasm of the PNW. A genome wide association study was conducted to discover marker trait associations, while accounting for population structure and kinship. A total of six significant marker trait associations were identified on chromosomes 1AB, 2A, 3BD, 4A, and 6A. Collectively these marker trait associations explained 29.9% (ranging from 0.3 to 14.2%) of the sponge cake volume variation. Previous research detected associations with agronomic, grain, flour, milling and baking traits on each of these chromosomes, however, none for sponge cake volume. This study serves as a foundation experiment by providing insights into the genetic architecture of sponge cake volume in a historical dataset.