TABLE 5.

Nodule initiation on primary roots of M. truncatula by S. meliloti 8530 and mutant strains

Inoculum strain	Avg no. of nodules/planta with avg root zone length (cm)d of:			No. of plants
	∼1 (above RT1)b	1.98 (RT1-RT2)c	∼11 (below RT2)
8530	0.5	1.1	1.5	84
8530 diluted 100-fold	0**	0**	4.1**	20
MG32 (sinI)	0**	0.4**	1.8	91
MG32 diluted 100-fold	0**	0**	2.2	19
Smb21221::pVMG	0.4	1.2	1.0	29
Smb21133::pVMG	0.4	1.2	1.1	35
Smc00154::pVMG	0.07**	0.8	3.7**	44
Smc00242::pVMG	0.03**	0.9	1.4	33
Smc01907::pVMG	0.04**	0.6**	2.4**	44
Smc01966::pVMG	1.0*	1.0	1.5	30
Smc02689::pVMG	0.2**	0.5**	1.1	36
Smc03930::pVMG	0.4	1.0	1.5	35
Smc04330::pVMG	0**	0.4**	2.5*	41
Uninoculated control (H2O)	0	0	0	18

^aAverage number of nodules per plant that differ significantly from the corresponding value for plants inoculated with the 8530 strain according to multiple analysis of variance tests are indicated as follows: **, P < 0.01; *, P < 0.05.

^bAverage number of nodules per plant on the primary root above the position of the root tip at the time of inoculation (RT1).

^cAverage number of nodules per plant on the primary root between RT1 and the position of the root tip 24 h after inoculation (RT2).

^dFor the 84 plants inoculated with the S. meliloti 8530 strain, above RT1 is the average length of the zone of developing root hairs at the time of inoculation, RT1-RT2 is the distance between RT1 and RT2, and below RT2 is the distance between RT2 and the bottom of the pouch.