Post-penetration development, pathogenicity and histological changes in ridge gourd infected by root-knot nematode (Meloidogyne incognita)

The ridge gourd (Luffa acutangula (L.) Roxb.) is a crucial warm-season vegetable crop cultivated extensively in India and tropical regions of Asia and Africa. Despite its medicinal significance and popularity in Indian cuisine, ridge gourd faces numerous biotic stressors, with root-knot nematodes (Meloidogyne spp.) being one of the most prevalent. This study aimed to investigate the post penetration development of Meloidogyne incognita on ridge gourd by assessing the pathogenicity and histopathological changes induced in the host plants. Under controlled laboratory and glasshouse conditions, experiments were conducted to observe nematode penetration and development stages, as well as the impact of nematode inoculum levels on ridge gourd growth parameters and chlorophyll content. Histopathological studies were performed to visualize anatomical changes in infected roots. The results demonstrated swift penetration and developmental progression of M. incognita within ridge gourd roots, culminating in reproductive stages. Pathogenicity assessments revealed a dose-dependent relationship between nematode density and plant damage, with higher inoculum concentrations resulting in significant reductions in growth parameters and chlorophyll content. Histopathological analyses revealed extensive damage to root tissues, including gall formation and anatomical abnormalities. This study enhances the understanding of the interaction of M. incognita with ridge gourd, emphasizing the need for effective management strategies to mitigate nematode-induced losses in agricultural productivity.