Phenotypic evolution of agricultural crops

Food crops are a vital source of nutrition for humans and domestic animals, with an estimated 4 billion metric tons of food produced per year. Crops do not only provide yields, but their traits also play a significant role in regulating the ecosystem processes of croplands, affecting local biotas, water balance, nutrient and carbon cycling. Domestication has led to significant changes in crop traits, making it important to understand the recent evolution of crops and how they differ from wild plants. In this paper I review the evidence on how the ecological traits of herbaceous crops have evolved during and after domestication. Loss of seed dispersal mechanisms, increased plant and organ sizes, high rates of consumption by herbivores and fast decomposition of residues by decomposer microbes in the soil, all have evolved independently in domestication processes of different crops. I also point out types of traits for which we have not identified common responses to domestication, be it because domestication processes of the different crop species are disparate, or because of lack of strong evidence. Those traits include resource acquisition rates of leaves and roots, and whole-plant growth rates. Then, I discuss research gaps in the field, including how to advance knowledge for those traits that show apparently idiosyncratic responses to domestication. Finally, I emphasize the importance of understanding the interactions of crops with other organisms and the environment to breed crops that deliver yield and other services required from croplands. To this end, I introduce an ideotype for sustainable agriculture, which might inspire the breeding of multipurpose herbaceous crops, in the same way than the ideotypes of the Green Revolution inspired the breeding of elite varieties to foster yields under conventional agriculture. Read the free Plain Language Summary for this article on the Journal blog.

Automated summary

Food crops are essential for nutrition and produce billions of tons of food annually. The traits of crops play a significant role in regulating ecosystem processes, but domestication has led to changes in these traits. This paper reviews the evidence of how ecological traits of herbaceous crops have evolved during and after domestication, highlighting the loss of seed dispersal mechanisms and changes in plant size and decomposition rates. The paper also discusses traits that have not shown common responses to domestication and research gaps in the field. Understanding crop interactions with organisms and the environment is crucial for breeding crops that meet the needs of agriculture.