Environment of origin and domestication affect morphological, physiological, and agronomic response to water deficit in chile pepper (Capsicum sp.)

PLoS One. 2022 Jun 14;17(6):e0260684. doi: 10.1371/journal.pone.0260684. eCollection 2022.

Abstract

Global climate change is having a significant effect on agriculture by causing greater precipitation variability and an increased risk of drought. To mitigate these effects, it is important to identify specific traits, adaptations, and germplasm that improve tolerance to soil water deficit. Local varieties, known as landraces, have undergone generations of farmer-mediated selection and can serve as sources of variation, specifically for tolerance to abiotic stress. Landraces can possess local adaptations, where accessions adapted to a particular environment will outperform others grown under the same conditions. We explore adaptations to water deficit in chile pepper landraces from across an environmental gradient in Mexico, a center of crop domestication and diversity, as well in improved varieties bred for the US. In the present study, we evaluated 25 US and Mexico accessions in a greenhouse experiment under well-watered and water deficit conditions and measured morphological, physiological, and agronomic traits. Accession and irrigation regime influenced plant biomass and height, while branching, CO2 assimilation, and fruit weight were all influenced by an interaction between accession and irrigation. A priori group contrasts revealed possible adaptations to water deficit for branching, CO2 assimilation, and plant height associated with geographic origin, domestication level, and pepper species. Additionally, within the Mexican landraces, the number of primary branches had a strong relationship with precipitation from the environment of origin. This work provides insight into chile pepper response to water deficit and adaptation to drought and identifies possibly tolerant germplasm.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Capsicum*
  • Carbon Dioxide
  • Domestication
  • Plant Breeding
  • Vegetables
  • Water

Substances

  • Water
  • Carbon Dioxide

Grants and funding

This research was funded by the US Department of Agriculture National Institute of Food and Agriculture through a grant from the Agriculture and Food Research Initiative (#GRT00047937) to KLM, LKM, MK, and LJB. Chile pepper collection trips were funded by the Center for Applied Plant Sciences, Ohio State University (caps.osu.edu) to KLM, LKM, EVDK, AM, and TM. Salaries and research support were also provided to LKM and KLM by state and federal funds appropriated to the Ohio Agricultural Research and Development Center, Ohio State University. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.