|GONZALES, J.J. - University Of Guadalajara|
|CORRAL, J.A. - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)|
|GARCIA, GUILLERMO - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)|
|OJEDA, GABRIELA - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)|
|DE LA CRUZ, LINO - University Of Guadalajara|
|Holland, Jim - Jim|
|MEDRANO, ROBERTO - University Of Guadalajara|
|ROMERO, GIOVANNI E. - Instituto Nacional De Investigaciones Forestales Y Agropecuarias (INIFAP)|
Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/29/2018
Publication Date: 2/16/2018
Citation: Gonzales, J.S., Corral, J.R., Garcia, G.M., Ojeda, G.R., De La Cruz, L.L., Holland, J.B., Medrano, R.M., Romero, G.G. 2018. Ecogeography of teosinte. PLoS One. 13:e0192676. https://doi.org/10.1371/journal.pone.0192676.
Interpretive Summary: We compiled the known geographic distributions of the closest wild relatives of corn (maize), a group of species called ‘teosintes’. Historical climate data for these sites was also compiled and the ecological range of each teosinte group was identified on the basis of key climate variables. Based on this information, we were able to identify the potential distribution of each type of teosinte, essentially the known geographic distribution plus contiguous sites with similar climate patterns. These newly defined potential distributions highlight locations that should be high priority for collecting new teosinte samples. This information can also be used for corn breeders looking for new sources of tolerance to climate stresses (from areas prone to flooding to very dry conditions). Finally, the geographic distribution information was useful to identify sites where unique teosinte populations exist, which should be a high priority for in situ conservation.
Technical Abstract: Adaptation of crops to climate change has motivated an increasing interest in the potential value of novel traits from wild species; maize wild relatives, the teosintes, harbor traits that may be useful to maize breeding. To study the ecogeographic distribution of teosinte we constructed a robust database of 2363 teosinte occurrences from published sources for the period 1842-2016. A geographical information system integrating 218 environmental variables was created for Mexico and Central America and was used to characterize the environment of each teosinte occurrence site. The natural geographic distribution of teosinte extends from the Western Sierra Madre of the State of Chihuahua, Mexico to the Pacific coast of Nicaragua and Costa Rica, including practically the entire western part of Mesoamerica. The Mexican annuals Zea mays ssp. parviglumis and Zea mays ssp. mexicana show a wide distribution in Mexico, while Zea diploperennis, Zea luxurians, Zea perennis, Zea mays ssp. huehuetenangensis, Zea vespertilio and Zea nicaraguensis had more restricted and distinct ranges, representing less than 20% of the total occurrences. Only 11.2% of teosinte populations are found in Protected Natural Areas in Mexico and Central America. Ecogeographical analysis showed that teosinte can cope with extreme levels of precipitation and temperatures during growing season. Modelling teosinte geographic distribution demonstrated congruence between actual and potential distributions; however, some areas with no occurrences appear to be within the range of adaptation of teosintes. Field surveys should be prioritized to such regions to accelerate the discovery of unknown populations. Potential areas for teosintes Zea mays ssp. mexicana races Chalco, Nobogame, and Durango, Zea mays ssp. huehuetenangensis, Zea luxurians, Zea diploperennis and Zea nicaraguensis are geographically separated; however, partial overlapping occurs between Zea mays ssp. parviglumis and Zea perennis, between Zea mays ssp. parviglumis and Zea diploperennis, and between Zea mays ssp. mexicana race Chalco and Zea mays ssp. mexicana race Central Plateau. Assessing priority of collecting for conservation showed that permanent monitoring programs and in-situ conservation projects with participation of local farmer communities are critically needed; Zea mays ssp. mexicana (races Durango and Nobogame), Zea luxurians, Zea diploperennis, Zea perennis and Zea vespertilio should be considered as the highest priority taxa.