CHANGES IN ALPHA- AND BETA-AMYLASE ACTIVITIES DURING THE MATURATION OF DIFFERENT BARLEY CULTIVARS

Abstract
The percentage of dry matter, kernel weight, α-amylase activity and β-amylase activity, were determined at several stages of kernel development, from anthesis to harvest, in seven cultivars of Canadian barley. These included 6-row barleys (Conquest, Bonanza, and Keystone), 2-row barleys (Betzes and Centennial), and two 6-rowed selections from crosses between 2-row and 6-row barleys. The patterns for development of β-amylase enzymes were similar in all cultivars, and these activities were low initially, followed by a period of increasing activities commencing about 10 days after anthesis and reaching maximum values 20 days later; they then remained constant until the kernels were harvested. α-Amylase activity increased in all cultivars immediately after anthesis and then decreased to low levels after 10 days of kernel development. The α-amylase activities of Conquest, Bonanza, and Betzes increased again to quite high levels after maturity and just prior to delayed harvesting, owing to unfavorable weather that caused sprouting in these cultivars.