Analysis of factors controlling dinitrogen fixation in wild and cultivated soybean (Glycine max) plants by reciprocal grafting

Abstract

Abstract This study was carried out to examine the factors controlling dinitrogen fixation in soybean. Reciprocal grafting in all combinations for the wild type (Glycine soja Sieb and Zucc line Nakei-No.l) and the cultivated type (Glycine max (L) Merr. cv. Tamahoniare) was performed. The results indicated that: 1. irrespective of root genotype, the plant combination with the shoot of the cultivated type, gave a significantly higher whole plant weight than that with the shoot of the wild type, suggesting the importance of the contribution of the shoot growth rate compared with that of the root, for the overall plant growth determination. 2. Total nodule activity was consistently and significantly higher in plants with shoot of the cultivated type than in plants with shoot of the wild type, and it was also slightly greater in plants with roots of the wild type than in plant combinations with the same shoot genotype. This finding also suggests that the shoot genotype is the major determinant of dinitrogen fi...