Inheritance of pollen-less anthers and "thrum" and "pin" flowers in periwinkle

Abstract

Two mutants, 1 with small, pollen-less anthers (OR-EA) and another with "pin" flowers (EMS 13-2), in contrast to "thrum" flowers found in normal periwinkle (Catharanthus roseus) plants, were isolated after induced mutagenesis in strain OR and cultivar, "Dhawal," respectively. Inheritance of these 2 traits, pollen-less anthers, and pin flowers was studied by crossing the mutants with their respective parental strains. Segregation ratios observed in F2 and testcross generations of the cross OR-EA x OR suggested that the pollen-less anthers trait was determined by duplicate recessive genes. Data obtained from F2 and F3 generations of the cross involving mutant EMS 13-2 with pin flowers and its parental variety Dhawal, suggested that production of pin (mutant) and thrum (normal) flowers was under the control of inhibitory epistatic interaction between 2 independently inherited genes. © The American Genetic Association. 2008. All rights reserved.