Patotyptest av potatiscystnematoden

Abstract: There are two species of potato cyst nematode (PCN), the yellow, Globodera rostochiensis, and the white, Globodera pallida. Each of them can appear in different pathotypes. These are separated by testing the nematode ability to multiply on a number of potato cultivars with different resistance properties. The aim of this project was to examine the virulence of Swedish and foreign PCN populations and to compare two test methods. Biotests are today the only available tests used to study virulence. Thus, there are so far no molecular tests that have been developed for this purpose. The investigations were carried out at Alnarp in a greenhouse at the Department of Plant Science, Division of Plant Protection and Resistance Biology, during the period May 2003 - January 2004. They comprised twelve different populations of potato cyst nematodes, nine Swedish and three foreign, tested on six potato cultivars. The used method with pots in a greenhouse seems to give somewhat more reliable results than the "closed container" method. A considerable difference in number of newly developed cysts between populations belonging to the same virulence groups appeared on all tested potato cultivars. This can be explained by a large genetic variation between populations and by the effects of population - cultivar interactions. The results of the tests will be used by the Nematology Laboratory at Alnarp in establishing a system to be used in a large scale testing of farmers´ samples. Based on the testing results, advice may be given of the choice of potato cultivars.