Assaf Distelfeld's Lab

Prof. Assaf DistelfeldInstitute of Evolution, HeadDepartment of Evolutionary and Environmental BiologyUniversity of HaifaMulti-purpose building, room 240199 Abba-Hushi AvenueHaifa 3498838Israel

In short: We study wheat domestication and explore wheat's wild-relatives as a source for wheat improvement

My work in the fields of plant genetics and breeding stems from a basic and applied research interests. A major challenge in biology is to understand the origins of morphological diversity—how form changes through evolution. As Darwin noted, domestication offers valuable insight into this problem by providing a direct path between ancestral and descendant species (Darwin Charles, 1859). I am interested in reconstructing the evolutionary history of crop plants, especially wheat. This evolutionary history is fundamental for understanding crop adaptation and the genetic basis of yield-limiting factors, which in turn are critical for future crop improvement. I decided to focus mainly on a wheat domestication and improvement utilizing collections of wild cereal germplasm available in Israel. In accordance, we have identified the causal mutations in Brittle Rachis 1 (TtBtr1) genes controlling shattering, a key domestication trait (Avni et al., 2017). A follow-up study, probed the geographical provenances of these mutations via haplotype analyses and show that Southern Levant played an important role in wheat domestication (Nave et al., 2019). In addition, we have identified a major locus controlling grain size and germination rate on wheat chromosome 4B. Identification of the gene underlying this QTL will reveal one of the most important survival mechanism of wild plants that was silenced during wheat domestication (Nave et al., 2016). Another important loci identified in our studies is controlling grain weight and the positive allele originates from wild wheat (Avni et al., 2018). We are currently dissecting the QTL region on chromosome 6AL and test the developed recombinant plants in field experiments. The year 2014 was critical because I realized that the efforts to assemble the wheat genome are far from completion and I decided to establish a consortium for assembling the genome of wild emmer wheat The idea was to use our high-throughput genetic map and the services of a big-data company (NRGene, Nes-Tziona, Israel) that developed a genome assembler software. I managed to gain support from other wheat researchers who contributed their skills and sequencing abilities. In the manuscript describing this project published in Science, we report a 10.1-gigabase assembly of the 14 chromosomes of wild tetraploid wheat, as well as analyses of gene content, genome architecture, and genetic diversity (Avni et al., 2017). The results were spectacular and convinced the community in our genome assembly strategy. Indeed, the international durum and bread wheat sequencing consortia decided to follow the same approach (IWGSC, 2018; Maccaferri et al., 2019). Recently, the first step of assembling 10+ wheat genomes, lead by Prof. Curtis Pozniak, was concluded and published in Nature journal.