|Ruiz Corral, J|
|Duran Puga, N|
|Ron Parra, J|
|Holland, Jim - Jim|
Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/17/2008
Publication Date: 7/1/2008
Citation: Ruiz Corral, J., Duran Puga, N., Sanchez, J., Ron Parra, J., Gonzalez, D., Holland, J.B., Medina, G. 2008. Climatic Adaptation and Ecological Descriptors of 42 Mexican Maize (Zea Mays L.) Races. Crop Science. 48:1502-1512. Interpretive Summary: To better understand the range of adaptation of maize landraces, climatic adaptation intervals of 42 Mexican maize races were determined. A database of 4161 maize accessions was used to characterize altitudinal and climatic conditions where the 42 maize races grow, yielding ecological descriptors for each race. Using the geographical coordinates of the collection sites of each accession, their climatic conditions were characterized using the geographic information system IDRISI and a national environmental information system. ANOVA and cluster analyses of the racial ecological descriptors were performed to determine possible environmental groupings of the races. We found a very high level of variation among and within Mexican maize races for climate adaptation and ecological descriptors. The general overall climatic ranges for maize were 0-2900 m of altitude, 11.3-26.6'C annual mean temperature, 12.0-29.1'C growing season mean temperature, 426-4245 mm annual rainfall, 400-3555 mm growing season rainfall, and 12.46-12.98 h mean growing season daylength. These climatic ranges of maize surpass those from its closest relative, teosinte, Z. mays ssp. parviglumis, indicating that maize has evolved adaptability beyond the environmental range in which ancestral maize was first domesticated.
Technical Abstract: Mexico is the center of diversity of maize. Thousands of collections of farmer varieties have been made in Mexico and these have been grouped into 42 races. We evaluated the ecological adaptation of these races by compiling information on the geography, altitude, temperatures, daylength, and annual rainfall for each site where the collections were made. Analysis of these data indicated that some races were broadly adapted to many diverse environments, whereas others were narrowly adapted to just a few environments. We identified races that were adapted to very dry conditions and may represent a source of drought resistance.