Desiccation tolerance in Dendroligotrichum dendroides (Brid. ex Hedw.) Broth. from two Chilean populations with contrasting precipitation

Resumo

Mosses are poikilohydrous non-vascular plants, usually with some degree of desiccation tolerance. Dendroid mosses have conducting tissues that make them analogous to vascular plants. Functional studies on these mosses, however, are scarce. Dendroligotrichum dendroides is a dendroid moss that occurs in Chile in the understory of temperate forests where it can be exposed to summer drought. We studied desiccation tolerance and rehydration capacity on D. dendroides from two populations with contrasting precipitation. We sampled plants from the northern part of their distribution (Contulmo, Araucanía district; lower precipitation), and from a southern population in Katalapi (Los Lagos district; higher precipitation). We measured relative water content and maximum efficiency of the PSII (Fv/Fm) in plants exposed to desiccation and rehydration. Plants from both populations showed desiccation tolerance and were able to recover their Fv/Fm after rehydration. However, the northern population lost water more slowly and recovered the Fv/Fm to higher values compared to the southern population. The northern population can be exposed to summer droughts. The southern population receives rain throughout the year. These differences could be attributed to local adaptation to the precipitation regimens of each site. Further studies are needed to unveil the physiological and biochemical mechanisms underlying the desiccation tolerance of D. dendroides.