title: Inheritance of tristyly in Oxalis tuberosa (Oxalidaceae).
abstract: Frequencies of floral morphs in progenies obtained from a complete set of diallelic crosses among three accessions of tristylous, octoploid oca (Oxalis tuberosa) were used for a Mendelian analysis of floral morph inheritance. The frequencies observed had the best fit to a model of tetrasomic inheritance with two diallelic factors, S, s and M, m, with S being epistatic over M. No explanation could be found for the unexpected formation of a small percentage of short-styled individuals in crosses between the mid-styled and the long-styled parent. For the acceptance of models of disomic and octosomic inheritance several additional assumptions would have to be made and therefore these modes of inheritance are less likely. Dosage-dependent inheritance of floral morph was rejected. Only a small frequency (36%) of the cross progenies flowered, in contrast to the greater propensity for flowering of O. tuberosa accessions held at gene banks.
authors.affiliation: International Potato Centre, Av. La Universidad 795, Lima 12, Peru. bodo.trognitz@arcs.ac.at
authors.forename: B R
authors.initials: BR
authors.lastname: Trognitz
authors.forename: M
authors.initials: M
authors.lastname: Hermann
mesh_terms: D000483:Alleles; D001947:Breeding; D003433:Crosses, Genetic; D004843:Epistasis, Genetic; D005787:Gene Frequency; D005799:Genes, Dominant / Q000235:genetics; D006579:Heterozygote; D006720:Homozygote; D008957:Models, Genetic; D010641:Phenotype; D011123:Polyploidy; D019685:Rosales / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*