Responses of thallus anatomy and chlorophyll fluorescence-based photosynthetic characteristics of two Antarctic species of genus Usnea to low temperature
Autor: | Peter Váczi, Andrea Hojdová, Miloš Barták, Michaela Bednaříková, Kateřina Trnková, Josef Hájek |
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Rok vydání: | 2021 |
Předmět: |
0106 biological sciences
Trebouxia Usnea Physiology usnea cstyle Plant Science lichen Photosynthesis 01 natural sciences lcsh:Botany Botany cross-sections Lichen Chlorophyll fluorescence biology Ice crystals Chemistry 04 agricultural and veterinary sciences biology.organism_classification lcsh:QK1-989 Cortex (botany) Thallus usnea aurantiaco-atra 040103 agronomy & agriculture 0401 agriculture forestry and fisheries temperature effects 010606 plant biology & botany |
Zdroj: | Photosynthetica, Vol 59, Iss 1, Pp 95-105 (2021) |
ISSN: | 1573-9058 0300-3604 |
Popis: | Biometrical parameters of two fruticose lichens from Antarctica (Usnea aurantiaco-atra, U. sphacelata) were studied using thallus cross-sections at basal, middle, and apical parts of thallus. The thallus diameter (TD), the thickness of the upper cortex (UCT), distribution of symbiotic alga (Trebouxia sp.) in the algal layer, the thickness of medulla (MT), central cord diameter, and area (CCD, CCA) were measured. U. sphacelata had comparable relative UCT (0.080-0.110, relative to diameter) to U. aurantiaco-atra (0.085-0.130). The relative MT was higher in U. sphacelata (0.240-0.300) than U. aurantiaco-atra (0.080-0.180). In U. aurantiaco-atra, the CCA was two times larger than that in U. sphacelata. Rapid freezing of thalli in liquid nitrogen led to an increase in TD, UCT, CCD because of intrathalline ice crystals formation. Cultivation of symbiotic alga at different temperatures (1.5, 6.0, 15.0, 22.0, and 28.0°C) with repetitive chlorophyll fluorescence parameters measurements showed growth optimum of 15.0°C for potential and effective quantum yield. |
Databáze: | OpenAIRE |
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