Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 30, 2010
Publication Date: December 14, 2010
Citation: Jansky, S.H. 2010. Parental effects on male fertility and agronomic performance of haploid-wild species hybrids. Euphytica. 178:273-281. Interpretive Summary: Diploid wild relatives of potato provide a rich source of valuable genes for cultivar improvement. These wild species can be crossed to diploid forms of the cultivated potato to produce adapted hybrids. This study was carried out to determine the extent to which the wild and cultivated parents contribute to fertility and agronomic traits in offspring. The wild species parent determines, to a large extent, the male fertility of hybrid offspring. The cultivated parent is important in determining the percentage of hybrid plants that are adapted to field conditions. Some wild species produce more agronomically acceptable offspring than others. This information will aid breeders in deciding what parents to use in germplasm enhancement breeding efforts.
Technical Abstract: Valuable genetic diversity in diploid wild Solanum species can be accessed through crosses to haploids (2x) of the cultivated potato, S. tuberosum. These hybrids segregate for the ability to tuberize in the field. In addition, they vary in male fertility, vine size, stolon length, and tuber size. In this study, three haploids were crossed with 11 diploid wild Solanum species and the 33 hybrid families were evaluated in the field for two years. The proportion of male fertile hybrid clones varied depending on the wild species parent. A large effect of the female parent was detected for vine size, stolon length, tuber size, percent tuberization, and percent plants selected for agronomic quality. An exceptional haploid (US-W4) was identified for the production of agronomically desirable haploid-wild species hybrids. In hybrids derived from US-W4, differences among wild species parents were observed for agronomic quality. Superior hybrids were produced by S. tarijense and S. microdontum. Reciprocal crosses were evaluated for a subset of families. When the wild species was used as the female parent, male fertility was restored, but tuberization and tuber size were reduced. Careful selection of both haploid and wild species parents can result in a large proportion of fertile, agronomically desirable hybrid offspring.