Diurnal Changes of β-Amylase Activity and its Isozyme Patterns of Alfalfa (Medicago sativa L.) Seedlings

[摘要] Diurnal changes in the activity of p-amylase and its isozyme patterns were examined in the seedlings of three-types of alfalfa (Medicago sativa L.) belonging to cultivars of three different types, i.e., extremely non hardy, intermediate and extremely hardy types. The results obtained are summarized as follows: 1. In all cultivars the p-amylase activity exhibited an alternating increase and decrease at every 3 to 6 hours interval. However, the tissue in which the highest and lowest p-amylase activity occurred in a day differed in cultivars, indicating varietal characteristics. 2. Within the β-amylase isozymes in alfalfa, the shoot tissues had the mainband A-5. Sub-band A-6 became detectable at the growth stage when the total activity was high. The total p-amylase activity and its isozyme banding patterns showed the same tendency, which made it possible to recognize varietal characteristics by means of β-amylase isozymes. 3. The p-amylase activity was higher in the stem tissues than in the leaves. This tendency was most remarkable in the extremely non-hardy type, but decreased gradually in the intermediate type and in the extremely hardy type. Although it is yet to be clarified, this tissue-specific differences in the p-amylase activity might reflect characteristics of cultivars.

[学科分类] 农业科学（综合）

[关键词] Alfalfa seedlings;アルファルファ幼植物;Amylase;アミラーゼ;Isozyme;アイソザイム;Diurnal change;日変化