ISSR MOLECULAR MARKERS FOR IDENTIFICATION OF AGAVE SPROUTS

Abstract

Mexico has a great diversity of Agave species, which has allowed the use of its fermentable sugars for production of alcoholic beverages such as tequila and mezcal. Both products are protected with a designation of origin but made from different agaves. While mezcal can be made from more than 14 species of Agave, tequila is only produced from Agave tequilana Weber cv azul. In recent years, new mezcal producers have been incorporated that do not have the ability to identify material to propagate, being the morphological characterization of the suckers an alternative, which is a demanding and sometimes inaccurate task, due to the lack of experience. In order to have a fast and reliable tool for the identification of Agave species, ISSR markers (Inter Simple Sequence Repeats) were evaluated to detect polymorphisms between species of Agave tequilana, A. angustifolia, A. potatorum and A. karwinskii, the last three used in the production of mezcal. Using suckers of each species, six ISSR primers were evaluated, presenting a differential and consistent amplification pattern. Using nine morphological parameters, it was determined by principal component analysis (PCA) that the first three components represent 70 % of the variation, with which it is possible to identify the evaluated agave species, which coincides in the grouping of these, with that obtained from the ISSR markers. The six primers evaluated are considered to be a fast and effective tool for genetic differentiation between species and that they can support regulatory organizations in complying with regulations to ensure the quality of mezcal and tequila, as well as large distilleries or palenques that have the need to buy their raw material from third parties.