The hybridisation of somatically chromosome-doubled dihaploid potatoes with tetraploid cultivars and the use of doubled dihaploids in genetic analysis of Solatium tuberosum

Three doubled dihaploid potatoes were hybridised with six tetraploid cultivars and the offspring examined for commercially important characters. Doubled dihaploids used as parents did not reduce the within progeny phenotypic variation for most characters below that found in material produced by intercrossing heterozygous tetraploids. They could however prove useful for improving some characters in a breeding programme. The products of the hybridisations were used to examine the genetic control of discrete variables such as tuber skin pigmentation, tuber flesh colour, and skin russetting. Doubled dihaploids were found to be useful for such studies because they have only three out of the five possible tetraploid genotypes. Presence or absence of red tuber skin in the progenies of cv. Désirée was concluded to be due to the segregation of a dominant major gene which was simplex in the parental cultivar. The yellow flesh of Desiree was found to be recessive. On the hypothesis that russet skin was due to three complementary dominant genes, possible genotypes of the doubled dihaploids and cultivars could also be deduced.