Cereal landraces genetic resources in worldwide GeneBanks. A review

Abstract

Since the dawn of agriculture, cereal landraces have been the staples for food production worldwide, but their use dramatically declined in the 2nd half of the last century, replaced by modern cultivars. In most parts of the world, landraces are one of the most threatened components of agrobiodiversity, facing the risk of genetic erosion and extinction. Since landraces have a tremendous potential in the development of new cultivars adapted to changing environmental conditions, GeneBanks holding their genetic resources potentially play an important role in supporting sustainable agriculture. This work reviews the current knowledge on cereal landraces maintained in GeneBanks and highlights the strengths and weaknesses of existing information about their taxonomy, origin, structure, threats, sampling methodologies and conservation and GeneBanks' documentation and management. An overview of major collections of cereal landraces is presented, using the information available in global metadatabase systems. This review on winter cereal landrace conservation focuses on: (1) traditional role of GeneBanks is evolving beyond their original purpose to conserve plant materials for breeding programmes. Today's GeneBank users are interested in landraces' history, agro-ecology and traditional knowledge associated with their use, in addition to germplasm traits. (2) GeneBanks therefore need to actively share their germplasm collections' information using different channels, to promote unlimited and effective use of these materials for the further development of sustainable agriculture. (3) Access to information on the 7.4 million accessions conserved in GeneBanks worldwide, of which cereal accessions account for nearly 45 %, particularly information on cereal landraces (24 % of wheat, 23 % of barley, 14 % of oats and 29 % of rye accessions), is often not easily available to potential users, mainly due to the lack of consistent or compatible documentation systems, their structure and registration. (4) Enhancing the sustainable use of landraces maintained in germplasm collections through the effective application of recent advances in landrace knowledge (origin, structure and traits) and documentation using the internet tools and data providing networks, including the use of molecular and biotechnological tools for the material screening and detection of agronomic traits. (5) Cereal landraces cannot be exclusively conserved as seed samples maintained under ex situ conditions in GeneBanks. The enormous contribution of farmers in maintaining the crop and landraces diversity is recognised. Sharing of benefits and raising awareness of the value of cereal landraces are the most effective ways to promote their conservation and to ensure their continued availability and sustainable use. (6) Evaluation of costs and economic benefits attributed to sustainable use of cereal landraces conserved in the GeneBanks requires comprehensive studies conducted on a case-by-case basis, that take into consideration species/crop resources, conservation conditions and quality and GeneBank location and functions. © 2012 INRA and Springer-Verlag, France.