Reproduction of virulent isolates of Meloidogyne incognita on susceptible and Mi-resistant tomato
Résumé
The reproductive potential of natural and laboratory-selected Meloidogyne incognita isolates virulent against the tomato Mi resistance gene, all derived from a single egg-mass, were compared when the nematodes were inoculated on susceptible and resistant tomato. Fewer second-stage juveniles (P = 0.01) of the two virulent populations selected under laboratory conditions matured to females on the resistant tomato compared to the susceptible cultivar. In contrast, no differences were found between the number of egg masses produced on the resistant versus the susceptible tomato by the two natural virulent isolates. No clear general trends concerning the fecundity of the females could be inferred from the comparative analysis of the numbers of eggs per egg mass x tomato cultivar combination. These observations suggested that the genetic changes induced under environmentally controlled nematode growth might be different from those occurring in natural Miresistance breaking biotypes grown without environmental control.
Mots clés
fecundity Lycopersicon esculentum Meloidog'yne incognita Mi gene nematode root-knot nematode tomato virulence
fecundity
Lycopersicon esculentum
Meloidog'yne incognita
Mi gene
nematode
root-knot nematode
tomato
virulence
fecundity Lycopersicon esculentum Meloidog'yne incognita Mi gene nematode root-knot nematode tomato virulence