Crop Genomic Diversity: A Contrast Between Annual and Perennial Systems

Among thousands of domesticated plants, a major distinction is the difference between annual and perennial life cycles. The domestication of perennials is expected to follow different processes than annuals, with distinct genetic outcomes. Here I will discuss those differences and focus on the fate of slightly deleterious mutations through genetic bottlenecks, with examples from the annual Asian rice (Oryza sativa) and the perennial grapes (Vitis vinifera). For the former, we show that domestication has not increased the net number of deleterious mutations per individual, but it has increased the frequency of deleterious mutations that survive the domestication process. These deleterious mutations are enriched within low recombination regions of the genome and within regions of putative selective sweeps that are likely linked to domestication phenotypes.