Seasonal patterns of photosystem 2 photochemical efficiency in evergreen sclerophylls and drought semi-deciduous shrubs under Mediterranean field conditions

Title:

Seasonal patterns of photosystem 2 photochemical efficiency in evergreen sclerophylls and drought semi-deciduous shrubs under Mediterranean field conditions

Creator:

Karavatas, S. and Manetas, Y.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:9b24a168-a1b1-485b-8d6e-0eb217769850
uuid:9b24a168-a1b1-485b-8d6e-0eb217769850
issn:0300-3604
doi:10.1023/A:1007010502269

Subject:

Arbutus, chlorophyll fluorescence kinetics, Cistus, Genista, Nerium, Phillyrea, Phlomis, Pistacia, relative water content, and Sarcopoterium

Type:

model:article and TEXT

Format:

bez média and svazek

Description:

Photochemical efficiency of photosystem 2 (PS2), assessed from in situ chlorophyll (Chl) fluorescence measurements, was seasonally monitored in five evergreen sclerophyll and five malacophyllous drought semi-deciduous species, co-occurring in the same Mediterranean field site. In evergreen sclerophylls, a considerable drop in the variable (Fv) to maximum (Fm) Chl fluorescence ratio coincided with the lowest winter temperatures, indicating low PS2 efficiency during this period. Summer drought caused a comparatively slight decrease in Fv/Fm and only in three of the five evergreen sclerophyll species tested. In drought semi-deciduous shrubs, the winter drop in Fv/Fm was much less conspicuous. During the summer, and in spite of the severe and prolonged desiccation of their malacophyllous leaves, Fv/Fm was maintained high and only in one species the PS2 efficiency was transiently suppressed, when the leaf relative water content became lower than 30 %. Thus evergreen sclerophylls are more prone to photoinhibition by low winter temperatures, while the sensitivity of drought semi-deciduals depends on the extent and duration of summer drought. and S. Karavatas, Y. Manetas.

Language:

Multiple languages

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Coverage:

41-49

Source:

Photosynthetica | 1999 Volume:36 | Number:1-2

Harvested from:

CDK

Metadata only:

false