Published online by Cambridge University Press: 27 March 2009
Comparisons were made of the tuber yield and leaf morphology of three dihaploids, their chromosome-doubled derivatives and tetraploid parthenogenetic parents grown in a glasshouse at low, medium and high fertilizer levels. Differences in yield between the dihaploids and doubled dihaploids were not significant (P > 0·05) and responses to increases in fertilizer were similar. Leaf complexity showed generally large (usually significant, P< 0·05) increases when the fertilizer level was increased from medium to high. For the heterozygous tetraploid parents the tuber yield increased more than leaf complexity. Probably the dihaploids and doubled dihaploids utilized the additional fertilizer to increase foliage growth rather than tuber yield whereas the converse was the case for the tetraploid parents. There was no evidence that chromosome doubling resulted in changes in the response of dihaploid genotypes to changes in the fertilizer level.