Resumo

FLORES, Joel  e  JURADO, Enrique. Germination of cacti species under risk status of the chihuahuan desert. Rev. mex. de cienc. forestales [online]. 2011, vol.2, n.8, pp.59-70. ISSN 2007-1132.

A synthesis of the main results of seed germination of 28 cacti under risk status and 4 without risk from the Chihuahuan Desert is presented here. The effect on germination of dormancy, light, seed age, seed competition and seed size were assessed. Three out of 17 taxa of the genus Turbinicarpus showed dormancy and two of them lost dormancy with age. Two Opuntia species also lost dormancy with age, aided by the presence of fungus that scarified the seed coat. From 28 cacti species at risk, 17 were dormant (germination ≤ 70%); and 11 non-dormant species were positive photoblastic that had small seeds (<1 mg). From the germination of two endemic columnar species, Isolatocereus dumortieri reduced germination at higher seed densities, while that of Myrtillocactus geometrizans was unaffected by seed density. 4 yr old small seeds from threatened Astrophytum myriostigma germinated faster and at higher per cent than large seeds. Future research lines are suggested to get a better understanding of cacti seed dynamics in current and future conditions in order to contribute to the preservation of these plants.

Palavras-chave : Cactaceae; seed dormancy; germination; seed scarification; desert plants; seeds.

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