Induction of nodule formation on M.
sativa cv. Europa by living bacterial cells of R.
tropici CFN299 carrying various combinations of R.
meliloti nod genes. (A) R. meliloti,
Rm2011; R. tropici, Rt299; R. tropici
(pGMI149), Rt (pGMI149); R. tropici
(pGMI149)(pGMI1962), Rt hyb. (B–D) R.
tropici (pGMI149)(pGMI1962) with Tn5
insertions in the R. meliloti nod genes carried in
pGMI149. (B) Mutations in the sulfation genes
nodP, nodQ, and nodH.
(C) Mutations in the nodFE and
nodL genes. (D) Mutations in the
nodA, nodB, nodC, and
nodIJ genes. Rt hyb, R. tropici
(pGMI149)(pGMI1962); Rt hyb D1-, R. tropici
(pGMI149nodD1)(pGMI1962) and so on. Nodule numbers
represent the average of 20 tubes, each containing two seedlings.
Statistical analysis of nodule numbers 2 weeks after inoculation:
treatments with letters in common do not differ significantly at the
P = 0.05 level. Analysis of variance with Fisher’s
test.