Viabilidad y germinación de semillas de cuatro especies amenazadas de cactáceas

[摘要] There are few studies about methods of evaluating the viability and germination of c a c t i seeds, key information to plan their conservation and preservation in their habitat or their survival for long periods under unfavorable environmental or storage conditions. In the present study, the viability of the seeds of the threatened Mexican species Echinocactus platyacanthus, Ferocactus pilosus, Lophophora williamsii, and Echinocactus grusonii, was explored with 2,3,5-triphenyl tetrazolium chloride (TZ) as well as their germination efficiency, in vitro and ex vitro. Seeds stored at room temperature for three years were used; viability was assessed with different concentrations of TZ. Germination rate and germination speed index (GSI) in the four species of cacti was assessed with different substrates. The viability of the seeds of E. platyacanthus was 87.5 % with 0.1 % tetrazolium chloride. The 98 % of germination percentage was obtained for F. pilosus without scarification and in organic forest soil-tezontle soil; the IVG was of 4.03 seeds per day. E.grusonii scarified with 1 min. in sulfuric acid germinated better (100 %) in the mixture of organic forest soil-tezontle soil and sand; both show a GSI of 8.3 and 8.1 seeds per day, respectively. There was a positive relationship between the tetrazolium viability test and the germination test. The topological staining patterns for each species were obtained and, in addition, reproduction methods were established, which may help in the conservation efforts of these endangered species.

[学科分类] 地质学

[关键词] cloruro de tetrazolio;GSI;índice de velocidad de germinación;vigor de semilla.