Genetic and malt quality diversity of East Asian two-rowed barley accessions in relationship to North American malting barley

Abstract

Because of epidemics of Fusarium head blight (FHB; caused by Fusarium graminearum Schwabe [teleomorph Gibberella zeae (Schwein.) Petch]) in the northern Great Plains of the United States and Canada in the past two decades, malting barley breeders have been forced to use nonadapted barley (Hordeum vulgare L.) accessions as sources of FHB resistance. Many of the resistant accessions are from East Asia, and limited information is available on their genetic diversity and malt quality. The objectives of this study were to determine the genetic diversity among 30 East Asian accessions and two North American cultivars. Genetic diversity was based on 49 simple-sequence repeat markers. All accessions were tested for barley grain brightness; protein content; 1,000-kernel weight; malting loss; fine-grind malt extract; content of plump kernels, free amino nitrogen, soluble protein, and wort β-glucan; the Kolbach index (i.e., the ratio of malt soluble protein to malt total protein); α-amylase activity; diastatic power; wort color; and wort viscosity. A few accessions had equal quality compared with Harrington and Conlon barley for individual traits but not for all. Qing 2, Mokkei 93–78, and Nitakia 48 could be excellent sources for increased malt extract; Nitakia 48 is a possible source for low wort viscosity; and Mokkei 93–78 and Nitakia 48 are putative sources of low β-glucan content. The cluster analyses also implied that the malt quality of an accession cannot be predicted based on the country where it was developed.