Identification of adapted breeding lines to improve barley hybrids for Spain

Abstract

This study explores the potential of Spanish germplasm for the development of hybrids adapted to southern Europe, a new region for hybrid barley (Hordeum vulgare). A set of 140 locally adapted, advanced breeding lines, developed in a Spanish public breeding program, were evaluated for their potential to widen the germplasm available for hybrid barley development. A subset of 24 lines was introduced into three-way hybrid combinations and tested in a field trial network of four locations and 2 yr. The hybrid performance of the rest of the lines was estimated based on genomic prediction models. No three-way hybrid exceeded the best check. We succeeded in identifying lines with high general combining ability, which could produce promising two-way hybrids. Some were among those tested in the field, whereas others resulted from genomic predictions, validating the strategy followed of mining locally adapted breeding lines. Rachis brittleness detected in field trials revealed a low but detrimental effect of the presence of alternative brittle mutations in the hybrid combination. The success of hybrid breeding in southern Europe requires further investigation of the underlying heterotic patterns, and appropriate management