Abstract
Recombination is a key evolutionary factor enhancing diversity. However, the eVect of recombination on diversity in inbreeding species is expected to be low. To estimate this eVect, recombination and diversity patterns of Lr10 gene were studied in natural populations of the inbreeder species, wild emmer wheat (Triticum dicoccoides). Wild emmer wheat is the progenitor of most cultivated
wheats and it harbors rich genetic resources for disease resistance. Lr10 is a leaf rust resistance gene encoding three domains: a coiled-coil, nucleotide-binding site, and leucine-rich repeat (CC-NBS-LRR). Results Lr10 was sequenced from 58 accessions representing 12 diverse habitats in Israel. Diversity analysis revealed a high rate of synonymous and non-synonymous
substitutions (dS = 0.029, dN = 0.018, respectively) in the NBS-LRR domains. Moreover, in contrast to other resistance genes, in Lr10 the CC domain was more diverse than the NBS-LRR domains (dS = 0.069 vs. 0.029, dN = 0.094
vs. 0.018) and was subjected to positive selection in some of the populations. Seventeen recombination events were detected between haplotypes, especially in the CC domain. Linkage disequilibrium (LD) analysis has shown a rapid
decay from r2 = 0.5 to r2 = 0.1 within a 2-kb span. Conclusion These results suggest that recombination is a diversifying force for the R-gene, Lr10, in the selWng species T. dicoccoides. This is the Wrst report of a short-range
LD decay in wild emmer wheat.
wheats and it harbors rich genetic resources for disease resistance. Lr10 is a leaf rust resistance gene encoding three domains: a coiled-coil, nucleotide-binding site, and leucine-rich repeat (CC-NBS-LRR). Results Lr10 was sequenced from 58 accessions representing 12 diverse habitats in Israel. Diversity analysis revealed a high rate of synonymous and non-synonymous
substitutions (dS = 0.029, dN = 0.018, respectively) in the NBS-LRR domains. Moreover, in contrast to other resistance genes, in Lr10 the CC domain was more diverse than the NBS-LRR domains (dS = 0.069 vs. 0.029, dN = 0.094
vs. 0.018) and was subjected to positive selection in some of the populations. Seventeen recombination events were detected between haplotypes, especially in the CC domain. Linkage disequilibrium (LD) analysis has shown a rapid
decay from r2 = 0.5 to r2 = 0.1 within a 2-kb span. Conclusion These results suggest that recombination is a diversifying force for the R-gene, Lr10, in the selWng species T. dicoccoides. This is the Wrst report of a short-range
LD decay in wild emmer wheat.
| Original language | English |
|---|---|
| Journal | Theoretical and Applied Genetics |
| Volume | 122 |
| Pages (from-to) | 175-187 |
| Number of pages | 13 |
| ISSN | 0040-5752 |
| DOIs | |
| Publication status | Published - 2011 |
| MoE publication type | A1 Journal article-refereed |
Fields of Science
- 1182 Biochemistry, cell and molecular biology