Abstract
To clarify the varietal characteristics in an native variety of white azuki bean ( Vigna angularis), of endemic name "Shiro azuki", ten strains collected from various parts of Akita prefecture were cultivated, and some morphological characteristics and yield components of those strains were investigated. The results are summarized as follows : Since ten strains showed large differences in the characters of weight of 100 grains per plant, those strains were grouped into three types (Grain-Size type, Medium type and Grain-Number type) on the basis of Grain-Number·100 Grain Weight ratio proposed by Matsumoto et al. in 1987. Grain-Number types exhibited relatively large number of braches compared to the Grain-Size types. Among the strains, the periods of vegetative growth became longer in strains of Grain-Number types than in those of Grain-Size types, while with regard to the period of reproductive growth there was not such variations. The frequence of occurrence of delayed pod maturation plants was significantly higher in Grain-Number types than in Grain-Size types. The delay of such ripening in Grain-Number types brought about a great disadvantage in seed-setting. Phenotypic correlations between sunshine hours (the mean values collected from May to Nov. during the past 16 years in the native place of each strain) and number of branches and grains per plants were highly positive respectively. On the other hand, there was a negative association between accumulated temperature (the mean values collected from May to Nov. during the past 27 years) and weight of 100 grains.
