Rayssa Garay Medina

Gametophyte Length Variation Among Antarctic Populations of Polytrichum Juniperinum Hedw. (Polytrichaceae)

Up to now, no sporophytes of Polytrichum juniperinum were recorded in Antarctica. erefore, the long distance dispersal may be a rare event in this continent. In this study, we recorded the length of gametophytes sampled in natural populations from an Antarctic island, aiming to evaluate the presence of patterns of morphological di erentiation related to short distance dispersal of vegetative propagules. e mean size of gametophytes ranged from 2.85±0.59 cm to 7.01±1.34 cm, with signi cant overall di erentiation according to the analysis of variance. e populations’ pair-wise comparison was signi cant in 20 out of 21 pairs. In terms of clustering of morphologically similar populations due to short distance dispersal, the degree of morphological di erentiation between sample locations slightly increased with geographical distance, although not statistically signi cant. Considering the absence of signi cant correlation between gametophyte size and geographic distance observed for the populations studied, adaptation to micro-environment seems to be the best explanation for the observed di erentiation. Further morphological records and studies based on molecular genetic markers are being developed by our group, in order to determine if such di erences have also some genetic basis.