Neglected landraces of collard (Brassica oleracea L. var. viridis) from the Carolinas (USA)

A common garden crop grown in the coastal plain region of North and South Carolina (United States) is the non-heading, leafy green type of Brassica oleracea L. known as collard (B. oleracea L. subsp. oleracea convar. acephala (DC.) Alef. var. viridis L.). Predominantly a fall and winter vegetable in this region, collard is often the only green planting to be found in the yard or garden of a rural home during these cool seasons. Historically, the traditional collard patch and even commercial fields were planted with unique varieties perpetuated by individual seed savers, and collectively, the regional diversity for this crop was probably very significant for well over a century. Genetic erosion of this collard germplasm pool has been severe in recent decades as commercial hybrids have been adopted by both large-scale producers and home gardeners. Although a significant number of collard landraces are being perpetuated to this day, existing diversity among landraces still grown in the region is now in the hands of an aging population of seed savers who maintain germplasm through on-farm preservation. From 2003 to 2006, we explored the coastal plain region of North and South Carolina in search of collard gardens containing traditional landraces. Exploration trips were conducted mid-winter to early spring. About 90 samples of collard were obtained from seed savers during the course of this exploration. Observations of morphological differences of these landraces indicate that significant diversity exists in this group. Obtained landraces are being deposited into the U.S. plant introduction collection and will be available for future use. This preserved collection could prove to be an important new source of genes for B. oleracea improvement.