Efectos del plomo y cromo en la germinación y arquitectura de raíz de plántulas de Typha latifolia (Typhaceae)

This research evaluates the effect of different concentrations of lead and chromium on root architecture and germination percentage of Typha latifolia. Seeds of Typha latifolia were collected from Yahuarcocha Lagoon (Ibarra-Ecuador). Pre-germinative treatments and exposure to lead concentrations of 50, 100, and 200 ppm, as well as 10, 20, and 40 ppm of chromium concentrations were applied to the seeds to measure the germination percentage. Regarding root architecture analysis, T. latifolia seedlings were grown for four weeks in 50% Hoagland solution and then transferred to rhizotrons, where the heavy metals were added to concentrations like the germination test. The seedlings were kept in these conditions for 15 days and variables such as number of roots, total area, and total length were recorded. Photographic records of the parameters under study were taken and analyzed in Image J and its SmartRoot extension. It was found that both heavy metals affected (significantly) the germination process, especially chromium. Germination percentages lower than 15% and 25% for lead were also obtained. Concerning root architecture, the number of roots and total length from heavy metal treatments were not significantly different from control. However, the total area treatment with chromium showed significant differences with respect to the control.