A Deletion Affecting Several Gene Candidates is Present in the Evergrowing Peach Mutant

Evergrowing (EVG) peach is one of only two described mutants affecting winter dormancy in woody perennial species. EVG peach does not set terminal buds, cease new leaf growth, nor enter into a dormant resting phase in response to winter conditions. The EVG mutation segregates in F2 progeny as a single recessive nuclear gene. A local molecular genetic linkage map around EVG was previously developed using amplified fragment length polymorphism (AFLP) and simple sequence repeat (SSR) markers, and a bacterial artificial chromosome (BAC) contig that contains the EVG mutation was assembled. A MADS box coding open reading frame (ORF) was found in a BAC of this contig and used as a probe. The probe detected a polymorphism between the wild-type and mutant genomes, and the polymorphism is indicative of a deletion in EVG peach. The EVG gene region contained six potential MADS-box transcription factor sequences, and the deletion in EVG affected at least four of these. The deletion was bracketed using RFLP analysis, which showed that it is contained within a segment of the genome no greater than 180 kb.