The First Genetic Linkages among Expressed Regions of the Garlic Genome

Garlic (Allium sativum L.) has been cultivated by asexual propagation since time immemorial. The discovery of male-fertile garlic accessions has opened a venue for genetic studies and improvement through sexual recombination. An S1 family of 84 plants was generated from a single male-fertile heterozygous plant from the U.S. Dept. of Agriculture Plant Introduction 540316 and used to identify the fi rst genetic linkages in garlic based on single nucleotide polymor- phisms, simple sequence repeats, and randomly amplifi ed polymorphic DNAs. Thirty-seven markers formed nine linkage groups covering 415 centimorgans (cM) with average distance of 15 cM between loci; other 16 loci remained unlinked. A male fertility locus was placed on the map. This fi rst genetic map of garlic is a seminal step toward the genetic improvement of garlic and eventual marker-assisted breeding. Garlic is an asexually propagated plant cultivated since time immemorial (Simon, 2004). The center of origin for garlic is central Asia, from which the plant spread worldwide and is now cultivated from mountainous tropical to temperate regions (Etoh and Simon, 2002). The bulb is the most economically important part of the garlic plant; however, its fresh leaves, pseudostems, and bulbils are also consumed by humans (Fritsch and Friesen, 2002). Although garlic is primarily consumed for its fl avor, it has well-defi ned medicinal benefi ts (Augusti, 1990; Block et al., 1984; Makheja and Bailey, 1990). The organosulfur compounds accumulated by garlic show signifi cant antibacterial, antifungal, anticarcinogenic, antiasthmatic, and antidiabetic properties, as well as lipid-lowering ability through inhibition of cholesterol