INVESTIGATIONS ON NON-NODULATING AND NODULATING SOYBEAN STRAINS

Abstract

Grafting experiments between a non-nodulating soybean strain and its near-isogenic nodulating sister strain indicated that the non-nodulating strain contained the cotyledon factor required for nodulation and did not contain a cotyledon factor inhibitory to nodulation. Root grafts were made on 1-day-old seedlings.Tetraploids produced by doubling the chromosome number of the non-nodulating isoline by means of colchicine failed to produce nodules.A biological assay utilizing a tryptophan-requiring mutant of Lactobacillus arabinosus showed that there was no quantitative difference in the amount of tryptophan exuded by the two isolines.