|Bach, Inga - DEPT AG SCI RVAU DENMARK|
|Olesen, Annette - DEPT OF HORT UW MADISON|
Submitted to: Journal of the American Society for Horticultural Science
Publication Type: Abstract Only
Publication Acceptance Date: January 8, 2000
Publication Date: N/A
Technical Abstract: Cytoplasmic male sterility (CMS) is a maternally inherited trait that has been associated with modifications of the mitochondrial genome or with incompatibility between nuclear and mitochondrial genomes. CMS is essential for development of highly adapted and uniform hybrid varieties of carrot and other high value crops. Internal recombination and change of the order of mitochondrial genes occurs frequently and can result in formation of chimeric genes. In a number of CMS plants of different species, the sterile phenotype is associated with the production of proteins arising from such chimeric genes derived from various known mitochondrial genes or from sequences of unknown origin. Two types of CMS have been observed in carrot: A sporogenous type, names "brown anther" in which the anthers are formed but shriveled, and a structural type, named "petaloid", in which the stamens are replace by petal or bract like structures. We have developed codominant and dominant mitochondria-specific PCR- based mar which distinguish fertile and petaloid carrot lines. The markers have been developed in regions of the mitochondrial genome that are known to be active in recombination or have shown some linkage or correlation to CMS in other species. A wide range of gene bank material has been evaluated with the developed markers. Some accessions of wild Daucus species have markers in common with petaloid carrot. These results indicate that the petaloid CMS type may be of alloplasmic origin.