抄録
In Japan, protein content of malting barley is required to be between 9.5% and 11.5% by brewing industry, but the farmer's product of dominant cultivars often shows more than the upper limit of the range. Therefore, it is important to develop cultivars with a low protein content in barley breeding. In this paper the succesive changes of the characteristics relating to grain nitrogen accumulation were studied in the six rowed low-protein malting barley cv. Karl, together with its two rowed offsprings Daikei HC-1 and Daikei HC-2. The rate of increase of grain dry matter exhibits significant changes during the ripening period. Therefore the period was divided into three phases, Iag phase (LP), Iinear increase phase (LIP) and late filling phase (LFP) (Fig. 1). The ratio (dN/dW) of grain nitrogen increase (dN) to grain dry matter increase (dW) was higher in the LFP than in the LIP.
