Waxy starch barley genotypes with reduced beta-glucan contents

Random inbred lines were produced from a cross between the genotypes Chalky Glenn and Waxy Hector, and two-row lines were classified as waxy or nonwaxy by an iodine staining test. Mean nitrogen and beta-glucan contents of the waxy types were higher than those of the nonwaxy types but, in contrast to previous data, mean milling energies of the two groups were not significantly different. Waxy lines with low milling energy had much lower beta-glucan levels than those with high milling energy, and they also demonstrated much more extensive cell wall modification during malting. From a trial grown the following season, the waxy types with low milling energy were again identified and had levels of beta-glucan content similar to those of nonwaxy types. beta-Glucan contents and, particularly, milling energies showed good agreement between seasons. It is suggested that, although waxy starch is usually associated with high beta-glucan content, a genetic factor from Chalky Glenn that confers low levels of beta-glucan can express in a waxy background.