GBS data and morphological nut trait data from two populations of hazelnut (<em>Corylus</em> spp.)

<p>The native, perennial shrub American hazelnut (<em>Corylus americana</em>) is cultivated in the Midwestern U.S. for its significant ecological benefits, as well as its high-value nut crop. Developing improved varieties for the Upper Midwest requires validated quantitative genetic approaches to utilizing genomic data in both American hazelnut and interspecific hybrids typical of breeding programs.  In addition, high-throughput phenotyping methods are essential to the efficient and accurate screening of large breeding populations.  This study reports novel advances in both of these domains.  Two populations of hazelnuts, one composed of <em>C. americana</em> and one composed of <em>C. americana</em> x <em>C. avellana</em> hybrids, were phenotyped over the course of two years in two locations using a digital imagery-based method for quantifying morphological nut and kernel traits.  This data was utilized to perform both composite interval mapping (CIM), using a recently released genetic map, and genomic prediction, using a newly available chromosome-scale reference genome for <em>C. americana</em>.  Multiple QTL were detected for all traits analyzed, with an average total R² of 52%.  Marker-assisted genomic selection exhibited high prediction accuracy, with an average correlation coefficient between genotypic values and phenotypic observations of 0.78 across both environments.  These results suggest that genomic prediction is a tenable method for improving genetic gain for highly polygenic traits in hazelnut breeding programs.</p>