D. Astley

Geographical Distribution of Wild Lactuca Species (Asteraceae, Lactuceae)

A broad survey of available world literature showed that at least 98 wildLactuca spp. (Asteraceae) have been described taxonomically. The distribution of the genusLactuca worldwide includes 17 species in Europe, 51 in Asia, 43 in Africa, and 12 in the Americas (mostly the North American subcontinent). Species originating in Asia, Africa, and the Americas form ca. 83% of knownLactuca spp. richness; however, they are very poorly documented from the viewpoint of taxonomic relationships, ecogeography, and variability. The phytogeography ofLactuca spp. regarding their distribution on different continents and in relation to the structure of the lettuce gene pool is discussed. A more detailed analysis of geographical distribution and habitats is given for some species (L. serriola, L. saligna, L. virosa, L. perennis, L. quercina, L. tatarica), which represent the primary, secondary, and tertiary gene pools of cultivated lettuce (L. sativa). Original and synanthropic distributions ofLactuca spp. and their occurrence in natural and secondary habitats are discussed, along with the representation of wildLactuca spp. in world gene-bank collections. Global biodiversity ofLactuca spp. and their representation in germplasm collections are poorly documented. Future studies of taxonomy, phytogeography, ecology, phylogenetic relationships, and genetic diversity are needed for a more complete understanding of this genus and taxonomically related genera.

Representation of wild Lactuca spp. (Asteraceae, Lactuceae) in world genebank collections

The spread of the genus Lactuca worldwide includes 16 species in Europe, 51 in Asia, 43 in Africa and 12 in America (mostly North American subcontinent). Natural distributions of Lactuca spp. are compared with the representation of wild Lactuca spp. in world genebank collections as recently summarized in the “International Lactuca database” (ILDB). A total of 27 wild Lactuca species are reported in world genebank collections in the ILDB, however, due to incorrect taxonomic determination the real number of species is lower. The substantial part (92%) of the collections is represented only by three species (L. serriola, L. saligna, L. virosa) and from a geographic viewpoint they are mostly European in origin. The autochthonous species originating from other continents (Asia, Africa, America), which form c. 83% of known Lactuca spp. richness, are very poorly represented in collections (only c. 3%). The majority of accessions originate from Europe (59%) and Asia (37%), nevertheless the whole area of natural distribution is not well covered. An extremely low number of accessions is available from Africa and America (2% each). Thus, the global biodiversity of Lactuca spp. germplasm is represented very poorly and is biased in genebank collections. For future studies of taxonomy, phytogeography, ecology, phylogenetic relationships, genetic diversity, inter- and intra-population structure, resistance research and practical breeding exploitation of wild Lactuca spp. germplasm, plant material from a wider ecogeographic distribution must be collected and introduced into genebank collections more intensively.

MORE EFFICIENT CONSERVATION AND USE OF VEGETABLE GENETIC RESOURCES IN EUROPE: ECPGR ACHIEVEMENTS AND PERSPECTIVES

The European Cooperative Programme for Plant Genetic Resources (ECPGR) is a regional network funded by the European countries and coordinated by Bioversity International. The Vegetables Network with representatives of 42 countries, is one of the crop specific ECPGR networks (http://www.ecpgr.cgiar.org/ networks/vegetables.html). It consists of six Working Groups (WGs), i.e., on Allium, Brassica, Cucurbits, Leafy Vegetables, Solanaceae and Umbellifer Crops. Sharing responsibilities for the ex situ conservation of European vegetable crops genetic resources is the highest priority of the Vegetables Network. It is foreseen that the rationalization of the collections will lead to higher cost-efficiency, and improvement of plant genetic resources documentation and quality. These efforts will be continued within the framework of the AEGIS initiative (A European Genebank Integrated System) (http://www.aegis.cgiar.org/). Challenges for the Vegetables Network include the identification of the so-called Most Appropriate Accessions (MAA) for each crop for their inclusion in the decentrally managed European Collection, and the development of agreed crop specific technical standards for conservation. Achievements of the Network in recent years include the development of European Central Crop Databases (ECCDBs), quality standards for collection man-agement of seed-propagated crops and cryopreserved material, safety duplication improvement and definition of minimum characterization descriptors. Several EU-funded projects have initiated and accelerated the activities of the WGs. Apart from further improvements within the framework of AEGIS, the Network is planning a number of other initiatives, such as improving collaboration at the global level (Allium), developing molecular characterization protocols (lettuce), filling the gaps in the conservation of wild relatives (Brassica and Umbellifer Crops), and improving the Network’s communication with the scientific community and the public at large.