RESISTANCE TO MYZUS-PERSICAE (SULZ) IN WILD POTATOES OF THE SERIES ETUBEROSA

Growth and feeding behaviour studies of Myzus persicae on Solanum spp., series Etuberosa, showed that the growth of aphids was least on S. brevidens. The mature leaves and top of S. brevidens and the young plants and top of S. etuberosum were resistant to M. persicae. However, the senescent leaves and basal axillary buds of S. brevidens, mature leaves of S. etuberosum and all the leaves of and top of S. fernandezianum were susceptible. Electric penetration graphs (EPG) were similar on the Solanum spp., and resembled those of Datura stramonium used as a susceptible control. However, the aphids least actively penetrated on S. brevidens and most actively on D. stramonium, the response on S. etuberosum and S. fernandezianum being intermediate and rather similar, although the numbers of probes and the total time used for probing were less on S. fernandezianum.