Differentiation among Maize (Zea mays L.) Landraces from the Tarasca Mountain Chain, Michoacan, Mexico and the Chalqueño Complex

Abstract

The classification of Mexican maize (Zea mays L.) begun since the early 20th century, it was consolidated during the middle of this century, but recent additions and rearrangements have been performed by several authors employing new methods of analysis and collections from diverse origin; nevertheless, maize from the State of Michoacan, Mexico has received little attention in regard to its systematic classification. Maize populations from the Tarasca Mountain Chain in Michoacan are commonly considered in literature, as belonging to the Chalqueno race; however, closer observations indicate that significant differences do exist, suggesting the necessity of performing an in-depth study on this respect. Thirty nine native maize populations from the Tarasca Mountain Chain region were evaluated along with 19 typical populations of the Chalqueno, Celaya and Conico races coming from the States of Mexico, Puebla, Hidalgo, Queretaro and Oaxaca. Populations were evaluated in Aranza, Michoacan and Montecillo, Mexico State. Seventeen morphological characters were scored and analyzed by one-way analyses of variance and multivariate techniques. Populations were also genetically analyzed through 17 isozyme loci. Native populations had some alleles not found either in the Chalqueno, Celaya or Conico races, and possess larger genetic diversity. Local populations were congregated into a discrete group apart from the typical Chalqueno populations, suggesting that landraces from the Tarasca Mountain Chain region might not be considered as belonging to the Chalqueno race, but they integrate by themselves a different race.