Relationship between photosynthesis and photorespiration in field-grown wheat leaves

Title:

Relationship between photosynthesis and photorespiration in field-grown wheat leaves

Creator:

Di Marco, G., Iannelli, M.A., and Loreto, F.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:45e5ddd5-296b-4414-b459-80f5f3afe299
uuid:45e5ddd5-296b-4414-b459-80f5f3afe299
urnnbn:urn:nbn:cz:aba007-000fjh

Type:

model:internalpart and TEXT

Format:

print

Description:

Simultaneous measurements of net photosynthetic rate {P^ and fluorescence were taken on flag leaves of fíeld-grown wheat {Triíicum aestivum L., Thlicum durum L.) from anthesis to senescence. By using leaf discs inaintained in saturating CO2 in tlie O2 electrode we found that the electron transport measured by fluorescence, and that calculated from O2 evolution rate were similar througliout the experimental period, which indicated that fluorescence might be ušed to measure the linear electron transport rate. In field measurements on intact attached leaves, the electron transport rate declined less than during leaf senescence, Measurements taken in the aftemoon indicated that the electron transport remained constant during the day while slightly decreased. Thus, in fíeld-grown wheat leaves photoinhibition was not a relevant phenomenon. When the alternativě electron routes were negligible, the increasing discrepancy between Pn and the electron transport during leaf senescence could be explained by an increment in photorespiration rate (Pp), The change of oxygenation to carboxylation ratio (Vq/Vj,) might be caused by increasing resistances to CO2 diffusion in the leaf CO2 lost through photorespiration was about half of that fixed with Pn in the sun-exposed leaves. Yet Pp was lower in the basal part of leaves which mostly grew in shade. Fluorescence coupled with gas exchange proved to be a useful method for evaluation of the photorespiratory losses in field conditions.

Language:

Multiple languages

Rights:

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

Coverage:

45-51 and 47-53

Source:

Photosynthetica | 1994 Volume:30 | Number:1

Harvested from:

CDK

Metadata only:

false