EFFECT OF PLANT PARASITIC NEMATODES ON OLIVE PLANTLETS OF XYLELLA-RESISTANT CULTIVAR FAVOLOSA

Abstract

Two experiments were carried out to verify the susceptibility of olive plantlets of the Xylella fastidiosa - resistant cultivar Favolosa to the root-knot nematode Meloidogyne javanica and the root lesion nematode Pratylenchus vulnus. In the first experiment the relationship between the nematode population density and the olive plants growth was assessed. Plant growth parameters, main shoot length and diameter and number of nodes, were analysed by the SeinFit program in order to calculate the tolerance limit (T) to the nematode attack and the minimum relative per cent growth (m) of the plants. In the second trial, the reaction of olive plantlets to P. vulnus was assessed by measuring the growth parameters after P. vulnus inoculations (200 juveniles/plant). The susceptibility to the nematode was evaluated on the base of the reproduction factor r = Pf/Pi according to r value: NH (non host) = Pf<Pi; PH (weak host) = Pi<Pf (maximum 300 nematodes/plant) and H (host) = Pf >300 nematodes/plant. For each trial ten replications were considered. Both trials indicated a susceptibility of the cv. Favolosa to both phytoparasitic nematodes despite of its resistance to Xylella fastidiosa.