NUCLEAR AND CYTOPLASMIC INTERACTIONS FOR PETALOID MALE-STERILE ACCESSIONS OF WILD CARROT (DAUCUS-CAROTA L.)

Male-sterile carrot plants with petaloid-stamens were discovered in wi ld populations in the vicinity of Guelph, Ontario, Canada and inherita nce of phenotype was assessed. Genetic analyses were also conducted to identify nuclear restorer genes of petaloid cytoplasmic male sterilit y (CMS) from wild carrot, and determine if Guelph, Cornell and Wiscons in cytoplasmic male-sterile accessions interacted similarly with allel es of restorer genes from different sources. Petaloid male-sterility w as inherited cytoplasmically for the new Guelph accessions, and nuclea r genotypes which normally produce 'green' or 'white' petaloid-stamens in combination with the Cornell cytoplasm also produced corresponding phenotypes when backcrossed to Guelph cytoplasmic accessions. Two dup licate restorer genes were identified from wild carrot. Dominant allel es of single restorer genes from three sources, one from wild carrot a nd two from cultivated germplasm, restored stamen production to Guelph , Cornell and Wisconsin petaloid cytoplasmic accessions, suggesting th at the cytoplasms were genetically identical.