Table 1.
Bacterial isolates used in this study.
Figure 1.
Effect of bacterial antagonists on repellence of M. incognita juveniles.
Juveniles were attracted by tomato roots and moved from a tube connecting two pots either to the side inoculated with an antagonistic strain or to the opposite side. Controls were inoculated on one side with the not antagonistic strain E. coli JM109, or left uninoculated. Juveniles penetrated into the roots were counted on both sides. Error bars represent standard deviations. Different letters indicate significant differences at P≤0.05 according to Tukey's test (n = 10).
Figure 2.
M. incognita reproduction affected by bacterial antagonists through induced systemic resistance of tomato.
Juveniles and bacteria were inoculated in opposite pots of split root systems. Controls were inoculated with the not antagonistic strain E. coli JM109, or left uninoculated. A: Experimental setup of the split root system. B: Mean numbers of galls (white bars) and egg masses (gray bars) counted 50 days after nematode inoculation; error bars represent standard deviations, different letters indicate significant differences at P≤0.05 according to Tukey's test (n = 10).
Table 2.
Effect of bacterial seed treatment on number of galls and egg masses of M. incognita after propagation on tomato plants.
Table 3.
Effect of bacterial culture supernatants on reproduction of M. incognita on tomato plants.
Table 4.
Effect of bacterial culture supernatants on plant growth of tomato infected with M. incognita.
Figure 3.
Comparison of the effects by direct and by plant-mediated antagonism on root penetration by juveniles.
M. incognita juveniles (J2) and bacterial strains were inoculated spatially separated in opposite pots of one split-root system (white bars), or co-inoculated with J2 in one pot of another split root system (gray bars). Controls were inoculated with J2 and the not antagonistic strain E. coli JM109, or only with nematodes. J2 penetrated into tomato roots were counted 10 days after inoculation (A). Numbers of galls (B), egg masses (C), eggs per root (D), and eggs per egg mass (E) were determined 50 days after J2 inoculation. Error bars represent standard deviations. Different letters indicate significant differences at P≤0.05 according to Tukey's test (n = 10).