Molecular analysis of sexual and asexual genetic variation of two sympatric Agave angustifolia varieties

Abstract

The genetic diversity using RAPD markers, between plants obtained through sexual and asexual reproduction of Agave angustifolia var. Lineño and var. Cimarrón collected in the southern region of the State of Jalisco, Mexico was evaluated. The two varieties studied are particularly important in the making of mezcal, and have been selected by producers in the region based on morphological characters, attempting to obtain an increasingly homogenous production with an improved quality. Despite this selection process, results obtained through RAPDs showed that there is a large genetic variation in these varieties, which is very important to preserve the genetic heritage in this species. In this study, RAPDs allowed a clear separation between the Lineño and Cimarrón varieties, being Lineño more genetically homogeneous than Cimarrón, putatively due to ancient domestication, and all analyzed individuals tended to group according to their mode of propagation. In terms of the clear separation of the two varieties in the case of seed–generated individuals, it is clear that although these varieties develop in the same habitat, they grow in a sympatric manner in their environment. Otherwise, there would be a closer relationship among formed groups, and it would be hard to separate seed–originated individuals of both varieties.