Inheritance in Chrysanthemum morifolium Ramat

Abstract

A study was undertaken to determine whether inheritance in the bivalent-forming, hexaploid Chrysanthemum morifolium is diploid-like (selective chromosome pairing) or hexasomic (random chromosome pairing). Self-compatible genotypes, nulliplex for the dominant allele I (Carotenoid Inhibitor), were crossed with I-possessing cvs. Pink Marble and Pollyanne. Segregation ratios for the progenies of the Pollyanne (putative triplex) crosses indicated hexasomic inheritance. Simplex selections from the Pink Marble progenies were selfed to obtain duplex genotypes with alleles of I on pairing homologues if diploid-like inheritance was occurring. However, subsequent crosses with the nulliplex cv. Canary gave progenies which segregated 4:1 (carotenoid–:carotenoid+), providing strong evidence for a hexasomic mode of inheritance. © 1989, The Genetical Society of Great Britain.