The agronomic value of tetraploid F1 hybrids between potatoes of Group Tuberosum and Group Phureja/Stenotomum

Selected tetraploid F1 hybrids, between Tuberosum cultivars and 2x Phureja clones, were compared with standard cultivars in randomized trials during the period 1980 to 1986 under conditions which simulated British agricultural practice. Hybrids were superior to standard cultivars in both total and marketable yield, and produced more tubers. We suggest that high yields in the 4x F1 hybrids result from the addition of complementary parental characters, high tuber numbers from Phureja and generally larger mean tuber size from Tuberosum. We discuss the role of heterosis in an interploidy breeding scheme utilising unreduced male gametes and emphasise the value of tetraploid hybrids between Tuberosum and improved Phureja.