A primary requirement of sunflower varieties for the UK is early maturity to avoid yield loss from infection by Botrytis cinerea of Scelerotinia sclerotiorum. Recombinant inbred lines selected in the UK following two cycles of inbreeding are being assessed in hybrid combination. The results of a trial of testcrosses produced between some French cytoplasmic male sterile lines (CMS) and the UK restorer lines are presented. Combining ability analysis indicated significant differences between both the CMS and restorer lines in their general combining abilities, but no differences in specific combining abilities for the yield-related characters. It was concluded that a number of these parental lines show potential as parents of hybrids for the UK. Analysis of correlations between the charâcters suggested that there were no barriers to obtaining hybrids with a favourable combination of traits for early flowering, short height, and high yield. TÏere was evidence of genetic control of resistance to Botrytis and Sclerotinia infection, and selection of such resistance should be an important breeding objective. The commercial varieties "Avante" and "Allegro" did not perform well in this trial.