Incorporating evolutionary and threat processes into crop wild relatives conservation.

Crop wild relatives (CWR) intra- and interspecific diversity is essential for crop breeding and food security. However, intraspecific genetic diversity, which is central given the idiosyncratic threats to species in landscapes, is usually not considered in planning frameworks. Here, we introduce an approach to develop proxies of genetic differentiation to identify conservation areas, applying systematic conservation planning tools that produce hierarchical prioritizations of the landscape. It accounts for: (i) evolutionary processes, including historical and environmental drivers of genetic diversity, and (ii) threat processes, considering taxa-specific tolerance to human-modified habitats, and their extinction risk status. Our analyses can be used as inputs for developing national action plans for the conservation and use of CWR. Our results also inform public policy to mitigate threat processes to CWR (like crops living modified organisms or agriculture subsidies), and could advise future research (e.g. for potential germplasm collecting). Although we focus on Mesoamerican CWR within Mexico, our methodology offers opportunities to effectively guide conservation and monitoring strategies to safeguard the evolutionary resilience of any taxa, including in regions of complex evolutionary histories and mosaic landscapes.

Chile (Capsicum spp.) as Food-Medicine Continuum in Multiethnic Mexico.

Mexico is the center of origin and diversification of domesticated chile (Capsicum annuum L.). Chile is conceived and employed as both food and medicine in Mexico. In this context, the objective of this paper is to describe and analyze the cultural role of chile as food and as medicine for the body and soul in different cultures of Mexico. To write it, we relied on our own fieldwork and literature review. Our findings include a) the first matrix of uses of chile across 67 indigenous and Afrodescendants cultures within Mexican territory and b) the proposal of a new model of diversified uses of chile. Traditional knowledge, uses and management of chile as food and medicine form a continuum (i.e., are not separated into distinct categories). The intermingled uses of Capsicum are diversified, deeply rooted and far-reaching into the past. Most of the knowledge, uses and practices are shared throughout Mexico. On the other hand, there is knowledge and practices that only occur in local or regional cultural contexts. In order to fulfill food, medicinal or spiritual functions, native communities use wild/cultivated chile.

Genetic diversity and structure in semiwild and domesticated chiles (Capsicum annuum; Solanaceae) from Mexico.

The chile of Mesoamerica, Capsicum annuum, is one of five domesticated chiles in the Americas. Among the chiles, it varies the most in size, form, and color of its fruits. Together with maize, C. annuum is one of the principal elements of the neotropical diets of Mesoamerican civilizations. Despite the great economic and cultural importance of C. annuum both worldwide and in Mexico, however, very little is known about its geographic origin and number of domestications. Here we sampled a total of 80 accessions from Mexico (58 semiwild and 22 domesticated) and examined nucleotide sequence diversity at three single- or low-copy nuclear loci, Dhn, G3pdh, and Waxy. Across the three loci, we found an average reduction of ca. 10% in the diversity of domesticates relative to semiwild chiles and geographic structure within Mexican populations. The Yucatan Peninsula contained a large number of haplotypes, many of which were unique, suggesting an important region of chile domestication and center of diversity. The present sampling of loci did not conclusively resolve the number and location of domestications, but several lines of evidence suggest multiple independent domestications from widely distributed progenitor populations.