Physiological and biochemical alterations in Capsicum annuum L. by the false root-knot nematode Nacobbus aberrans.

Abstract

Nacobbus aberrans is responsible for producing significant production losses in numerous crops. For this reason, it is considered a major economic pest in several countries. In recent years, its incidence increased mainly in greenhouse crops. This work focused on the responses of various physiological and biochemical parameters of pepper plants growing in a soil infected by nematodes. The experiment was conducted under controlled conditions. A significant reduction in growth was observed in the inoculated plants, showing less accumulation of dry matter both in the aerial part and in the roots. The leaves of the inoculated plants presented lower chlorophyll and soluble proteins contents than the non-inoculated plants. Malonyldialdehyde content was higher in roots and leaves of inoculated plants than in plants without nematodes. An increase in the catalase and peroxidase activity was observed in plants infected by N. aberrans. The loss of functionality of the inoculated roots induced water stress.This was also confirmed by a greater accumulation of proline and sugars, metabolites used as osmoregulators in situations of water deficit.