The origin and distribution of the golden nematode and its potential in the U.S.A.

Abstract

Potato cyst-nematodes,Globodera pallida andG. rostochiensis (golden nematode), and their preferred host, the potato, originated in the Andes of South America. Both were introduced into Europe from the Andean region, the potato about 1570 and the nematode nearly 300 years later. Potato cyst-nematodes are believed to have been introduced into Europe in the 1850’s along with potato collections from the Andes for use in breeding for late blight resistance, but the nematodes went unnoticed until 1881. Since that time the nematodes have spread to virtually everywhere that potatoes are grown, as one or both species have now been reported from 47 countries. It is believed that the golden nematode was introduced into the U.S.A. from Europe on military equipment brought back after the First World War to Long Island, NY, but the nematode was not recognized until some 20 years later. Yield losses in countries with general infestations of potato cyst-nematodes are probably 9% or more; the potential for losses is greatest in countries where average yields are greatest, such as the U.S.A. Good resistance to the pathotype of the nematode that occurs in the U.S.A. is commercially available. If all potatoes grown in the U.S.A. contained this resistance, further spread would be restricted and the golden nematode could perhaps be eliminated from the U.S.A.; but the present supply and diversity of resistant varieties are insufficient for the total potato acreage. Restricting spread of the golden nematode in the U.S.A. minimizes costs borne by growers and government agencies in dealing with the pest. At present, the most promising approach to restricting spread is through management systems developed for keeping nematode densities below the critical level above which spread will occur. If the golden nematode is to be contained, management systems must eventually be applied to all potato acreages. Increased research effort is needed to develop resistant varieties, resistance to a broad range of pathotypes, nematode management systems, and biological control