English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

This study aimed to evaluate the effective photosyntheticquantum yield ( Phi PSII) and the Photochemical ReflectanceIndex (PRI) for assessment of photosynthetic performance of twoUmbilicaria lichens during gradual desiccation of their thalli.U. cylindrica and U. decussata exhibited curvilinearrelationship (S-shape curve) of decreasing Phi PSII values withdecreasing water potential (WP) of thalli. During initial phaseof desiccation (WP from 0 to -10 MPa), no decrease of Phi PSIIwas apparent, further desiccation (WP from -10 to -20 MPa) ledto fast Phi PSII decrease from 0.6 to 0.1 indicating stronginhibition of photosynthetic processes. Critical WP at whichphotosythetic processes are fully inhibited was found bellow-25 MPa in both lichen species. Photochemical Reflectance Index(PRI) exhibited curvilinear increase with thalli desiccation(decreasing WP). At full thallus hydration, the PRI reached thevalue of -0.18 in both species. Under strong dehydration (WPfrom -20 to -30 MPa), however, U. cylindrica showed somewhatlower value (-0.04) than U.decussata (-0.02 MPa). PRI to WPrelationship is discussed and compared to existing evidencefrom higher plants and poikilohydric organisms.

Interspecific differences in photosynthetic efficiency and spectral reflectance in two Umbilicaria species from Svalbard during controlled desiccation