Genetic Improvement of Leek (Allium ampeloprasum L.)

Abstract

Leek (Allium ampeloprasum L.) is an autotetraploid (2n = 4x = 32), mainly outcrossing, monocotyledon and one of the economically-important crop species from the Amaryllidaceae family. The origin of leek is believed to be in the eastern Mediterranean region. It is widely distributed across the Mediterranean Basin through the Middle East, Europe and all over the world. Leek has enormous economic importance all around the world for many purposes such as vegetable, medicinal herb, food seasoning and candidate source of food synthetic preservatives. Leek, as a vegetable, provides essential vitamins (A, B, C, E and K), minerals (iron, calcium, magnesium, potassium, phosphorus, sodium and zinc), proteins, fats, carotenoids and phytonutrients to the human body. Moreover, it is rich in secondary metabolites, such as phenolic acids, flavonoids (kaempferol) and flavonoid polymers. Leek is not only valued for its nutritional value but also for various biological activities including antimicrobial, anti-cancer, cardio-protective, cholesterol lowering, antioxidant and others. Leek is a seed-propagated crop cultivated as a biennial crop. Leek breeders have a major problem to produce homozygous lines. It is necessary to develop new leek cultivars with enhanced productivity and adaptability by employing modern biotechnological tools. This chapter presents an overview of the origin, distribution, taxonomic position, genetic resource characterization and conservation, current cultivation practices, germplasm biodiversity and conservation, traditional breeding methods, tissue culture applications, genetic engineering, mutational breeding, hybridization and future directions in leek improvement programs.