Oriental Mustard Origins Traced Back 7000 Years

VANCOUVER - Mar 28/13 - SNS -- A genetic study by researchers at the University of Western Australia (UWA), The University of Melbourne, Department of Primary Industries Victoria, and institutes in India and China has generated more clues about the origins and diversity of oriental or Indian mustard seed.

Brassica juncea is now widely grown in Australia, India, China, Europe and Canada and has been a standard item in Indian and Chinese cuisine for thousands of years, particularly in pickles and mustard greens.

Assistant Professor Sheng Chen of UWA's School of Plant Biology and UWA Institute of Agriculture is the lead author of the study published this week in the Journal of Heredity. His colleague, Assistant Professor Matthew Nelson, and Winthrop Professor Wallace Cowling of UWA's Institute of Agriculture and School of Plant Biology were among the co-authors.

"Mustard has been cultivated for up to 7000 years in China, where it is used as both an oilseed and vegetable crop," the authors write. It is the predominant oilseed crop in India and has been an important component of Indian agriculture since 2300 BC."

The study investigated mustard's molecular genetic diversity as the Indian and Chinese types are distinct and adapted to different environments.

The study brought together scientists from China, India and Australia, and was supported by the Australian Centre for International Agricultural Research and the Grains Research and Development Corporation.

The Indian type is brown-seeded and adapted to autumn sowing in northern and central India where winters are mild and dry. Chinese types – both yellow and brown-seeded – are adapted to spring sowing in higher parts of central and western China while others in China are winter-hardy.

Plant scientists have disagreed for many years about mustard's origins. Using molecular markers, the authors of this study gained a unique insight into the evolution of this important plant and concluded that in ancient times there were two "waves" of migration of Brassica juncea into India and China from West Asia and places such as Afghanistan. The Indian and Chinese agricultural types separated from each other during thousands of years of cultivation and selection, but are joined in history and ancestry through these waves of migration.

The researchers believe that understanding the heritage of Brassica juncea will help broaden even further the genetic diversity of the crop and breeding for the future.