Level of Endogenous Cytokinins and Auxin in Roots of Nematode Resistant and Susceptible Peach Rootstocks1

Cytokinin and auxin levels were examined in the roots of peach cultivars, resistant (‘Nemaguard’ and ‘Okinawa’) and susceptible (‘Baladi’ and ‘L 198-12’) to the root knot nematode Meloidogyne javanica . This approach was taken in the light of our earlier finding that this nematode developed and completed its life cycle in seedlings of a resistant cultivar when they were wick-fed with kinetin and 1-naphthylacetic acid (NAA). The cytokinin activity in roots of resistant rootstocks was significantly lower when compared with susceptible rootstocks. Wick-feeding with kinetin and NAA increased cytokinin-like activity in the roots of a resistant rootstock. Significant differences were found in the activity of several basic-ether soluble auxin-like growth promoters.