Toward the Identification of Cytoplasmic Male Sterility in Leek: Evaluation of Organellar DNA Diversity among Cultivated Accessions of Allium ampeloprasum

Abstract

Hybrid leek is more uniform and higher yielding than open-pollinated cultivars and is presently produced by asexual propagation of a genic male-sterile plant. A cheaper method to produce hybrid leek seed would be a system of cytoplasmic-genic male sterility (CMS). Restriction fragment length polymorphisms (RFLPs) in the organellar genomes have correlated with CMS in many crops. We undertook gel-blot analyses of the chloroplast and mitochondrial DNAs to assess cytoplasmic diversity among 62 accessions of the major cultivated forms of Allium ampeloprasum L. (leek, kurrat, and great-headed garlic). No polymorphisms were detected in the chloroplast genome of leek and kurrat. Three accessions of leek and one of kurrat possessed one or two of seven polymorphic mitochondrial probe-enzyme combinations. Great-headed garlic differed from leek and kurrat for six polymorphisms in the chloroplast genome and for many mitochondrial probe-enzyme combinations. Our analyses revealed few organellar polymorphisms among accessions of leek and kurrat, reducing the probability that selection of polymorphic cytoplasms will reveal CMS in leek.