Histopathological changes caused by Meloidogyne incognita on almond (Prunus amygdalus).

Severe root damage induced by a population of Meloidogyne incognita was observed in a naturally infested almond orchard in southern Sicily. The nematode attack was favoured by the susceptibility of the unselected rootstocks and the sandy soil. Several large galls were visible on principal and lateral roots, inducing a severe reduction of the radical system functionality. The giant cells observed into the vascular cylinder, were characterized by a dense cytoplasm, hypertrophy, heterochromatic nuclei, and thicker cell walls. The feeding sites caused interruptions, reductions and alterations in the continuity of the vascular tissues. In parasitized plants the production of almond nuts was lower both in quantity and quality.