SUPERNODULATION IN INTERSPECIFIC GRAFTS BETWEEN GLYCINE-MAX (SOYBEAN) AND GLYCINE-SOJA

Nitrate tolerant symbiosis (nts) soybean Glycine max (L.) Merr. mutants, altered in theirautoregulation response to allow extremely high (supernodulating) levels of nodulation were used in grafting experiments with the normal wild-type variety Bragg and a closely related species Glycine soja Sieb. and Zucc. Where the nts mutant was used as the shoot, supernodulation levels of nodule numbers were seen on both G. soja and soybean roots. Where either G. soja or the wild-type Bragg was used as the shoot, normally autoregulated, lower levels of nodulation were seen on all root types. These data confirm the shoot control of supernodulation, and that this phenomenon can be induced on another legume species by a mutant Glycine max shoot. This may suggest a similar method of chemical signalling to induce autoregulation amongst legumes. © 1987, Gustav Fischer Verlag, Stuttgart. All rights reserved.