ENDOPHYTIC FUNGAL COMMUNITY ASSOCIATED WITH THE DICOTYLEDONOUS PLANT COLOBANTHUS QUITENSIS (KUNTH) BARTL. (CARYOPHYLLACEAE) IN ANTARCTICA

Luiz Henrique Rosa (UFOP); Mariana de Lourdes Ameida Vieira (UFMG); Iara Furtado Santiago (UFOP); Carlos Augusto Rosa (UFMG)

The distribution and diversity of fungal endophytes are described here in the leaves of Colobanthus quitensis (Caryophylaceae), the only dicotyledonous plant present in Antarctica. Five hundred ten leaf segments from 170 plant specimens were collected from six different sites at Admiralty Bay on King George Island, in the Antarctica Peninsula. A total of 186 fungal isolates were obtained and identified by sequence analysis of the internal transcribed spacer region (ITS) of the rRNA gene. Sequence analyses of the ITS region revealed the presence of 19 different taxa represented by species from the genera Aspergillus, Cadophora, Davidiella, Entrophospora, Fusarium, Geomyces, Gyoerffyella, Microdochium, Mycocentrospora, Phaeosphaeria, and nine unknown fungal taxa. Davidiella tassiana was the prevalent species, followed by two possible new species of endophytic fungi, UFMGCB 2478 and 2668, present with 21.9, 16.4 and 14.4% abundances, respectively. Twelve taxa had low sequence identities when compared with the sequences of the fungi deposited in GenBank, and could represent new fungal species. Four fungal endophytes recovered from C. quitensis were similar to species previously found in leaves or roots of the Antarctic grass Deschampsia antartica (Poaceae). In general, the diversity indexes obtained for the endophytic fungal community associated with C. quitensis were lower than those obtained for fungal communities of temperate and tropical plants. This work shows that C. quitensis is an interesting reservoir of saprobes and pathogenic and new endophytic fungal species, and could be a community model to further ecological and evolutionary studies as well as the study of mechanisms of adaptation of these microorganisms to extreme conditions.