Assessment of a Method Using Plantlets Grown Previously In vitro for Studying Resistance of Prunus cerasifera EHR. (Myrobalan Plum) to Meloidogyne Spp.
Plantlets of two genotypes of Prunus cerasifera resistant to Meloidogyne arenaria, and one susceptible genotype, were rooted in vitro with and without 0.5 ppm indolebutyric acid (IBA). Seventy days after transplanting plantlets into greenhouse pots containing a sandy soil, they were inoculated with 0, 500, 1 500, or 4 500 second-stage juveniles (J2) of M. arenaria. Two months later, root galling and nematode development were evaluated. Galling was absent in the resistant genotypes P.1079 and P.2175 at all inoculum levels and no nematode reproduced regardless of the in vitro rooting medium used. In IBA-rooted plantlets of the susceptible genotype P.2032, nematodes reproduced normally and the ratios of developmental stages were unaffected by inoculum level, suggesting no appreciable intraspecific competition even at 4 500 J2/plant. Plantlets of P.2032 that had been rooted in medium supplemented with IBA were much more homogeneous than those rooted without IBA. The results indicate, the
