Novel Plant Defences Against Nematodes

Abstract

Nematodes are major pests of world agriculture (Nickle, 1991) and they have a global economic impact of >$100 billion per year (Sasser and Freckman, 1987). The most prevalent cause of economic loss in climates other than temperate ones are species of Meloidogyne, root-knot nematodes. Their wide host ranges ensure they are a major constraint on the development of agriculture in the tropics where they impose losses of 11–25% to a wide range of crops (Sasser, 1979). In contrast, cyst nematode (Heterodera and Globodera spp.) predominate in temperate agriculture and each species has a narrow host crop range. Species that are key pests of their respective crops include soybean (Heterodera glycines) sugar beet (Heterodera schachtii) and potato (Globodera spp.) cyst nematodes. For instance, potato cyst nematodes (Globodera pallida and Globodera rostochiensis) infest 40% of the UK national potato acreage. They are believed to impose an annual cost of £10–50 million on the industry in that country; the two Globodera spp. are also important in other potato growing areas.