Kernel Morphology and Malting Quality Variation in Lateral and Central Kernels of Six-Row Barley

Abstract

The size and shape of barley kernels are of interest to the malting and brewing industry because they influence malting quality. Barley researchers have theorized that the generally higher extract of two-row versus six-row barley is due to the smaller size and lower extract level of lateral kernels of the six-row types. This study was conducted to quantify kernel morphology variation in six-row barley and to assess whether an opportunity exists to improve malting quality of six-row barley by enhancing lateral kernel size. Lateral and central kernels of a historical set of six-row genotypes were evaluated for malting quality and kernel morphology. Digital image analysis was used to quantify kernel morphology variation in the kernel types. Central kernels had higher kernel weight (7.1 mg), plumpness (20.2%), malt extract (1.3%), diastatic power (18.9°L), and α-amylase (2.8 20° units) than did laterals. Image analysis showed that central kernels were longer (0.5 mm), wider (0.10 mm), and larger (2.2 mm2 area) than were laterals in these cultivars. Both kernel types were substantially improved for all traits in newer genotypes. Digital image analysis was useful in assessing kernel morphology variability between and within cultivars and for demonstrating that an opportunity exists to improve quality of six-row barley by enhancing lateral kernel size.