The 2012 ASHS Annual Conference

Brassica juncea L. Czern. with vegetable, flavoring and oil potential has been a neglected genetic resources as far as collecting of indigenous germplasm in Korea is concerned. Howerver, rapid agricultural intensification means that the genetic diversity of wild species is severely threatened. Responding to these needs, the natural habitat and distribution of wild or weed types of leaf mustard (Brassica juncea L. Czern.) were surveyed from 2004–07 in the Korean peninsula, in Jeju Island, and in Ulleung Island, and the seeds were collected and their habitat population size were investigated. The natural populations of wild mustard were found in different location in the southern and western parts of the Korea peninsula, in Jeju Island, and in Ulleung Island near fields, roadsides, riversides, and residences. The population size were larger in the southwestern part than in other regions. The colors of seed coat were brown, dark brown, and yellow. Most of the collected samples were long-day plants, and flowering in April in the field, but some samples flowered regardless the day-length. These materials were conserved in National Agrobiodiversity Center, NAAS, RDA, and will used for breeding and research materials in future.