CONCLUSION
We used RenSeq to sequence the R gene libraries of S. integrifolium plants from across a rainfall gradient to evaluate the hypothesis that CMI imposes a biotic stress whose evolutionary pressure should be evident within the genome. We detected a significant positive relationship between CMI and R gene count, supporting our hypothesis. We demonstrate that RenSeq can be used in the evaluation of ecological hypotheses and show promise for the economical interrogation of the specific R gene loci responsible for disease resistance.