Characterization of non-nodulation mutants of soybean [Glycine max (L.) Merr]: Bradyrhizobium effects and absence of root hair curling

Characterization of non-nodulation mutants of soybean [Glycine max (L.) Merr]: Bradyrhizobium effects and absence of root hair curling

1987

A:PS

The characterization of the non-nodulation mutants nod49, nod139 and nod772, isolated from mutagenized soybean cv. Bragg seeds, as well as the naturally occurring rj1 mutant is described. Mutant nod49 has been characterized in greatest detail. Mutants nod49 and nod139 lack curled root haris when inoculated with Bradyrhizobium japonicum USDA 110 at medium (1.0E7-1.0E8 viable cells/ml) cell numbers. Mutant nod772 shows occasional hair curling. All mutants occasionally formed nodules; nodulation was more frequent at higher concentrations of inoculant. Such nodules are normal in morphology and nitrogenase activity. Bacteria isolated from nodules on nod49 retain the nodulation properties of the original inoculant and do not suppress the non-nodulation phenotype. Field grown nod49 and nod139 plants are non-nodulated. Co-culture of nod49 or nod139 with Bragg plants indicate that the non-nodulation mutants like rj1 do not alter the phenotype of the parent cv. in a positive or negative way. Thus there is no evidence at this stage that the mutants are deficient in a nodulation related root exudate signal. The results indicate that these mutants are blocked in a very early stage of nodulation. The stage of blockage as well as attempts to circumvent non-nodulation are discussed. [AS]

v.131:349-361, JOURNAL OF PLANT PHYSIOLOGY

Research > Published Articles