Endogenous factors controlling stem growth habit of soybean plants. I. Comparison of abscisic acid levels in determinate and indeterminate types.

Abstract

Soybean plants show diversity in stem growth habit ranging from determinate type to indeterminate type. Stem growth of determinate type plants abruptly terminates near flowering, while that of indeterminate type plants continues after flowering. In order to elucidate endogenous factors controlling such growth habit of soybean plants, ABA levels in leaves and pods of determinate and indeterminate isolines were compared. No differences were found in ABA levels, which suggests that ABA in not involved in stem termination of soybean plants. Some unknown factors seem to cause the stem termination.