PHENOTYPIC DIVERSITY OF MAIZE LANDRACES FROM THE CENTRAL-EASTERN HIGHLAND PLATEAU OF PUEBLA STATE, MÉXICO

Abstract

In México, the State of Puebla is on the ninth place in maize (Zea mays L.) production; 41 % comes from the District for Rural Development ‘Libres’, where maize landraces are the main varieties sown. The present study was conducted with the purpose of assessing the level of phenotypic diversity present in the maize landraces cultivated in that District, and studying the phenetic relationships among such materials and the races reported for the Highlands of México. A total of 134 landraces from 22 communities of the District were collected in the years 2006 and 2007, and were evaluated in 2007 at three sites, along with six controls representing the races Palomero Toluqueño, Conico Norteño, Cónico and Chalqueño (with its variants Crema and Palomo). Twenty-two traits were measured (phenological, of the tassel, ear and grain). The analyses of variance, clusters and principal components indicated the presence of a considerable phenotypic diversity among maize populations, which was expressed as a continuous of variation in attributes such as days to 50 % silking, plant and ear height, length of the central branch of the tassel, ear diameter, row number and grain length. Certain similarity was detected among native populations and the Chalqueño race and its variant Chalqueño Crema, but none with the other racial controls. These findings suggest that a fraction of the native populations is departing morphologically from the races reported for the region. It was also observed that the selection that farmers are imposing on traits such as precocity, plant height and yield components is resulting in the development of distinct groups of populations.