The effect of plant-parasitic nematodes on severity of bacterial wilt in solanaceous plants.
Plant parasitic nematodes were recorded in 9 locations in central Taiwan where bacterial wilt of solanaceous plants (caused by Ralstonia solanacearum) occurred. The plants investigated included tomatoes, tobacco, aubergines and Capsicum annuum. The nematodes identified included the root-knot nematode, Meloidogyne incognita, and the lesion nematode Pratylenchus penetrans. The disease ratings of bacterial wilt in treated plants (1, inoculated with M. incognita or P. penetrans and one month later with R. solanacearum; 2, inoculated with R. solanacearum and 2 weeks later with the nematodes; or 3, inoculated with nematodes and R. solanacearum simultaneously) were higher than ratings in plants inoculated with bacteria only. It is concluded that a complex infection of plant-parasitic nematodes and R. solanacearum increased disease severity and reduced the resistance of bacterial wilt-resistant solanaceous plants.