Reproductive variation and germination capacity of Tillandsia landbeckii Phil. in the southernmost Tillandsia dune of the Atacama Desert

Tillandsia landbeckii Phil. is a rootless epiphyte that grows on dunes of the Atacama Desert. There is little information on its naturalhistory, particularly concerning its reproductive ability. To better understand whether sexual reproduction can contribute torecruitment in T. landbeckii, we examined its basic reproductive traits and developed a germination protocol. We marked andcensused plants, as well as collected seeds from four localities along an inland-coast gradient of the southernmost Tillandsia dunein Chile. Seeds were tested for viability and used for germination trials using four culture mediums. Plants vary in size, capsulesize and number of seeds per capsule along the gradient, with larger plants occurring inland. Both the probability of flowering andof producing capsules increased with plant size. However, seed viability was low and did not differ across localities. Germination trialswere successful, but also yielded relatively low germination probabilities. In summary, our results revealed plant size-relatedvariation in T. landbeckii’s reproductive capacity. In spite of this variation, however, low seed viability supports previous findingsthat sexual reproduction scarcely contributes to recruitment in this population; hence propagation of this species may eventually benecessary to promote genetic diversity.