Mitochondrial genome variation in Allium ampeloprasum and its wild relatives

Limitation in mitochondrial genome diversity of leek, revealed by restriction fragment length polymorphism (RFLP) analyses with mitochondrial gene probes, prevent a cytoplasmic male sterility (CMS) system in elite populations. However, mitochondrial genome diversity was detected in Allium ampeloprasum L. wild accession and landraces, as well as in pearl onion. Within this plant material, nine mitotypes were distinguished and could be used in order to broaden the genetic basis of leek. A chimeric mitochondrial gene configuration is usable as a marker for the sterility inducing cytoplasms (S₁) in chives (Allium schoenoprasum L.) and in onion (Allium cepa L.) for (S) and (T) cytoplasm. This chimeric mitochondrial gene configuration is also present in the subgenus Allium, revealed by polymerase chain reaction (PCR). However, only a faint amplicon was observed in a few accessions investigated herein, suggesting that this fragment might be present to a lesser level in mitochondrial DNA, as a sublimon.