Varietal and germinative characterization of Agave potatorum (Asparagaceae) seeds with different origins

Background: Agave potatorum reproduces mainly through seeds is widely collected for the mezcal production, and there is currently a marked decrease in their wild populations. Therefore, to contribute to its sustainable use, it is important to characterize the morphology of its seeds and to know their germinative characteristics. Research question: Do the year and the collection site have an effect on the size, color, viability and germination capacity of Agave potatorum seeds? Species studied: Agave potatorum Zucc. Study site and period of research: Seeds of Agave potatorum were collected in Oaxaca, Mexico: Miahuatlán (MIAH), in 2014; Coixtlahuaca (COIX), in 2015; and Zaachila (ZAA), in 2015 and 2016. Methods: For the seeds, we analyzed four physical descriptors, five color coordinates, and nine germination variables. We used a completely randomized design with four replications (100 seeds). An analysis of variance, a comparison of means, and a linear correlation analysis were performed. Results: We found that the ZAA16 seeds showed the highest values (P < 0.05) for weight and size, and for the luminosity coordinate (L*, 15.2). Color coordinate values revealed a black color of the seeds, which significantly diminished in luminosity with seeds age and varied with their origin. The coordinate L* was correlated significantly with the total dry weight of seedlings and seed volume. Conclusions: Agave potatorum seeds significantly changed their physical dimensions and germination capacity according to their origin. The luminosity of the black color of seeds decreased with seed age and was correlated with seed volume and seedling total dry weight.