A PCR-marker for the CMS(1) inducing cytoplasm in chives derived from recombination events affecting the mitochondrial gene atp9.

The complete coding and 3;-flanking region of the mitochondrial gene atp9 of chives ( Allium schoenoprasum L.) was determined in order to develop primers that allow the identification of atp9-related sequences in subsequent PCR-amplifications. One of these sequences is of a chimerical nature, consisting of atp9-homologous regions on its end, interrupted by an insertion that is composed of one atp6-homologous part and one part of unknown origin. This PCR-fragment is 762 bp in size and exclusively amplified in the sterility inducing cytoplasm of CMS(1). Thus it can be used as a PCR-marker in order to distinguish this cytoplasm type from the remaining cytoplasm types of chives. The chimerical marker sequence forms a putative open reading frame ( orfA501), from which CMS(1) might originate.