Genetic analysis of the most acidic 11S globulin subunit and related characters in soybean seeds.

The A5 subunit is the most acidic subunit of soybean 11S globulin. The inheritance of A5 Subunit was studied by analyzing electrophoretically the crude 11S globullns in single seeds of F1 and F2 generations of four crosses. A part of these seeds were used to investigate the genetic relationships between A5 subunit and other characters, i, e., basic subunits, 11S globulin composition, 11S/7S ratio and seed protein content. The content of A5 Subunit was under the control of the alleles (Gl1, gl1) at one locus and highest in Gl1Gl1, about half of Gl1Gl1 in Gl1gl1 and zero in gl1gl1. The presence or absence of A5 Subunit and two specific basic subunits was entirely coordinated with each other, therefore, it was suggested that the structural genes coding for A5 subunit and two specific basic subunits were closely linked with each other to constitute Gl1 or the synthesis of these subunits was synchronously controlled by Gl1 and gl1. The presence of these subunits was accompanied by the most acidic 11S globulin molecule which is missing in gl1gl1. 11S/7S ratio was closely related to Gl1 gene dosage and highest in Gl1Gl1, intermediate in Gl1gl1 and lowest in gl1gl1. These results show that Gl1 is responsible for increasing heterogeniety of 11S globulin molecular species and raising 11S/7S ratio. There were no significant differences in protein content among three genotypes and 11S/7S ratio was not correlated with seed protein content so that these genes will have no effect on protein content and increasing 11S globulin may not decrease protein content.