Evolutionary biology, genetics and genomics, domestication and crop improvement, in crop wild relatives of cereals and lettuce.

The Wild Cereal Gene Bank (ICGB) and Wild Lettuce Gene Bank (ILGB), at the Institute of Evolution, University of Haifa.

Israel and the surrounding in the Near East Fertile Crescent, the region of old-world agriculture, served as an important center for the domestication of plants and animals which established the foundations for the development of human civilization. Wild emmer wheat, Triticum dicoccoides, wild barley, Hordeum spontaneum, and wild Lactuca species, are excellent models of crops wild relatives (CWR), for advancing research in plant evolution, population genetics and genomics, domestication and crop improvement.

CWR offer a rich repertoire of beneficial alleles that can be deployed for crop improvement. Ex-situ and in-situ conservation and preservation of the extensive genetic diversity of crop progenitors can contribute to food security, especially in view of climate change and increased food demand caused by the continuous growth of the world population. About 20% of world plant diversity is under threat due to rapid processes of urbanization, habitat over-exploitation and degradation. It is widely accepted that CWR harbor genetic diversity that can potentially improve the crops nutritional value, productivity, and resilience to biotic and abiotic stresses; however, their diversity is often missing and poorly represented in gene banks. Therefore, the preservation of genetic diversity of CWR in gene banks around the world is of primary importance. However, gene banks vary greatly in terms of their scopes, some of them collect, preserve, and catalogue biological material, while others maintain active research programs that generate pre-breeding materials and valuable knowledge for further research and plant breeding. The main objectives of the Wild Cereals Gene Bank (ICGB) and the Wild Lettuce Gene Bank (ILGB), at the Institute of Evolution (IOE), University of Haifa, are to collect, preserve, and exploit the unique and rich gene-pools of wild cereals and lettuce from Israel as the basis for active theoretical and applied research.

The ICGB, established in the mid 70’s by Prof. Eviatar Nevo, harbors extensive collections of more than 18,000 accessions of wild cereals, including wild emmer wheat (Triticum dicoccoides) (6,025 acc.), and wild barley (Hordeum spontaneum) (5,915 acc.), the prime progenitors of cultivated wheat and barley, distributed along the Near East Fertile Crescent, with centers of origin and diversity in north Israel and Golan Heights. Most of the collections originated from diverse ecologies in Israel and surroundings, in the Near East Fertile Crescent, including Turkey, Iran, and Jordan. The collection also includes 10 Aegilops species (1,910 acc.) which belong to the secondary gene pool of cereals; wild oat (Avena spp.) (985 acc.), and two species of Brachypodium (1,750 acc.).

The ILGB harbor seed samples of ~4,950 accessions of nine wild Lactuca species (Compositae (Asteraceae)). The objectives of the ILGB are related to the identification, collection, distribution, conservation and sustainable use of these unique genetic resources for breeding. Our studies include eco-geographical distribution, genetic and phenological polymorphism, downy mildew resistance, variation of biologically active sesquiterpene lactone contents, and vernalization requirements. In addition, our research focus on the characterization of the population structure of wild Lactuca relatives (WLR) originating from southwest Asia, the center of diversity for WLR. Our studies are based mainly on new collections of L. serriola L. - the most likely progenitor of cultivated lettuce, Lactuca sativa L., one of the most important and widely distributed leafy vegetables - L. aculeata Boiss., L. georgica Grossh., and L. altaica Fisch. & C.A. Mey (representing the primary Lettuce Gene Pool, LGP-1) and L. saligna (LGP-2) from Israel and Armenia, as well as some accessions collected in past from Jordan, Turkey, and in many European countries into which wild lettuce expanded.

The GB collections originate from individual plants collected in natural populations across Israel along aridity gradients, occurring from north to south and from west to east, and in local microsites with variable (or contrasting) ecological factors. Thus, the collection sites vary greatly in terms of climatic (rainfall, temperature and humidity), edaphic (soil types), and topography (altitude, slope) variables. Hence, these collections represent wild cereals and lettuce adapted to a wide range of habitats and eco-geographical conditions at macrogeographic (regional) and microgeographic (local) scales. The unique gene pools of cereals and lettuce species were studied for their genetic adaptation to plethora of biotic and abiotic (a/biotic) stresses. Our studies identified regional and local genetic patterns which are partly or largely adaptive at the protein and DNA levels, both at coding and noncoding genomes, correlated with and predictable by environmental a/biotic stresses. The wide genetic diversity of these unique gene pools can be further exploited for crop improvement by identifying novel genes and alleles, contributing to increased grain protein and mineral content, disease resistance, and drought resistance. These genetic resources are uniquely and particularly important for advancing agriculture and food production, in view of the decline in genetic diversity of the cultivars and their increased susceptibility against environmental stresses. The new science of ecological genomics was particularly emphasized in the IOE publications, which highlight the intimate relationship of ecological stresses and genetic and genomic adaptive complexes.

The wide and extensive research conducted during the last 40 years at the IOE, based on the ICGB and ILGB collections, resulted in more than 330 publications in leading international journals. Among these publications, it is worth mentioning the cloning of the high grain protein gene, Gpc-B1, from wild emmer wheat (Uauy et al., Science, 2006; 314:1292-1301); the cloning of the wild emmer wheat gene Yr36, conferring resistance to stripe rust disease of wheat (Fu et al., Science, 2009; 323, 1357-60); the assembly of physical map for chromosome 1BS of wheat (Raats et al., Genome Biology, 2015; 14: R138); and the cloning of the wild emmer wheat gene, Yr15, conferring resistance to stripe rust which have led to the discovery of a new protein family termed as “tandem kinase-pseudokinase (TKP)” protein family (Nature communications, 2018; 9, p.3735). In addition, the exciting genomic analysis of 6,000-year-old cultivated barley grains, discovered in a cave on the cliff of the Masada Horst facing the Dead Sea and the Judean Desert, highlighted the domestication history of barley (Macher et al. Nature Genetics, 2016; 48, 1089-1093).

Nevertheless, it seems that most of the rich genetic resources of wild crop relatives from Israel are still untapped and await their efficient exploitation and utilization for crop improvement, advance modern agriculture and food production, in a continuous effort to safeguard the future of humankind.

The new home for the ICGB

A new home for the ICGB is currently built at the University of Haifa. The construction of the new home for the gene bank is supported by the generous donation of Lady Barbara and Sir Mick Davis, Prof. Alfred I. Tauber, Co-Founder of the Laszlo N. Tauber Family Foundation, and supported by University of Haifa and Israel Science Foundation (ISF) grants.

From the model to reality – Our dream is about to come true!

Beginning of construction 1st May 2020