About 12,000 years ago, the Neolithic Revolution brought about dramatic changes in the economy, diet, and structure of the first human societies in the Fertile Crescent in the Near East. With the beginning of the cultivation of grains – such as wheat and barley – and the domestication of animals, the first cities emerged in a new social context characterized by a productive economy. Now, a study published in the journal Trends in plant sciences Co-led by the University of Barcelona, the Agrotecnio Center and the University of Lleida, it analyzed the evolution of wheat mutants since it began to be cultivated by the people of ancient Mesopotamia – the cradle of world agriculture – between the Tigris and Euphrates rivers.
The study authors are Rut Sánchez-Bragado and Josep Lluís Araus-Ortega, from the UB Faculty of Biology and Agrotecnio-UdL; Gustavo A. Slaver, ICREA Researcher in the UdL College of Agri-Food and Forestry Sciences and Engineering, and Gema Molero, of the International Center for Maize and Wheat Improvement in Mexico, currently a researcher at KWS Seeds Inc.
Pills that changed human history
The cultivation of wheat – the grass that became a staple food – marked a turning point in the progress of human civilization. Today it is the most important crop in the world in terms of food security, but European Union data warn that the impact of climate change could lead to a significant increase in its price and modification of its production process in certain regions of the world.
During the process of wheat domestication, the plant phenotype underwent both rapid (within a few hundred years) and slow (thousands of years) changes, such as weakening of fry, increase in seed size, and reduction or disappearance of seeds. umbrellas. In particular, dark and non-dark cultivars of wheat are found worldwide, although the latter tends to be abundant in regions with arid climates, especially during the final stages of cultivation in late spring, a case typical of Mediterranean environments.
“It is important to conduct studies that show which types of wheat are most suitable for different environmental growing conditions, particularly in the context of climate change. A retrospective study can give us an idea of the evolution of wheat cultivation over the thousands of years since the advent of agriculture in ancient Mesopotamia,” he says. says Root Sanchez Bragado, first author of the study, who received his Ph.D. from the University at Buffalo.
“Umbrellas are members of the spike traditionally associated with plant adaptations to drought conditions,” says Josep Lluís Araus, professor in the Department of Evolutionary Biology, Ecology and Environmental Sciences in the College of Biology.
However, archaeological and historical records show that rising wheat was mostly present with umbrellas more than ten thousand years after the domestication of wheat. It was not until the last millennium that evidence showed the absence of umbrellas, suggesting selection by farmers—perhaps in a manner Indirect – against this organ,” confirms Araus, one of the most cited authors in the world according to research by Clarivate Analytics (2022).
“The role of wheat umbrellas in their performance remains controversial despite decades of studies,” says researcher Gustavo A. Slaver, corresponding author of the study.
Spike umbrellas: good for plants?
Is the presence of umbrellas on the spike useful for plants and crops? Although there is no scientific consensus, “everything indicates that in conditions where the plant is not experiencing water stress, the additional photosynthetic capacity of canopies does not compensate for other potential negative effects (reduced susceptibility to fungal diseases, reduction in the total number of Big ones that are supported by the ear, etc.),” says Araus.
“However, in wetter climates, canopies accumulate moisture and can promote the spread of disease,” says Rote Sanchez Bragado. “Therefore, with the global population increasing continuously, it is necessary to investigate the role of umbrella mutations in the changing conditions of our climate in order to meet the global demand for a staple food commodity such as wheat.”
In arid conditions, the spikes—including the umbrellas—”have better physiological characteristics than the leaves. In addition, the umbrellas allow the light captured by the crop to be more diffused, facilitating a better distribution of light energy and allowing the crop to increase photosynthesis.” Therefore, in conditions Arid, the umbrellas can remain beneficial to the crop, or at most neutral, ”concludes Professor Josep Luis Araus.