The UNVEILING THE ENIGMA OF LIVERWORTS IN CANGAS

INTRACAPSULAR GERMINATION AND LIPID RESERVES IN TWO CHEILOLEJEUNEA SPECIES (SPRUCE) STEPH. (LEJEUNEACEAE)

Résumé

Intracapsular germination of spores can occur in the three phyla: Bryophyta, Marchantiophyta, and Anthocerothophyta. This strategy allows for the protected development of young plants during the early stages. However, knowledge is scarce on the germination and establishment of the species Cheilolejeunea xanthocarpa (Lehm. & Lindenb.) Malombe and Cheilolejeunea discoidea (Lehm. & Lindenb.) Kachroo & R.M. Schust, making it difficult to understand their life history and ecology. Therefore, the goal of this study was to record the intracapsular germination of these two liverwort species found in areas of Cangas. Three colonies of C. xanthocarpa and C. discoidea were collected in Cangas, in the Serra da Calçada Natural Monument, Minas Gerais. The samples were collected and cultivated on climatized room. After one week, the mature sporophytes were analyzed, and the released spores were stained with Sudan Black and Sudan Red to identify lipid reserves. During the analysis, different stages of development of the sporophytes were observed. The colonies showed a significant amount of mature sporophytes, containing sporelings with multiple cells, lipid reserves, and rhizoids. These lipid reserves found in spores and sporelings indicate an energy reserve for the establishment of juvenile gametophytes. These characteristics are advantageous for the effective establishment of plants on tree trunks and branches. Our understanding is that the larger spores make it difficult to disperse by wind over long distances. The discovery of intracapsular germination and lipid reserves in the protonemas of these species raises questions about the adaptive strategies of these plants for establishment under stressful conditions. This information is important for understanding the reproductive biology of liverworts and their ecology. Furthermore, considering the diversity of bryophyte species in Brazil and the lack of studies on the reproductive biology of these species, this study contributes to filling knowledge gaps in these plants.