|
Document Type |
: |
Article In Journal |
|
Document Title |
: |
Gas exchange and chlorophyll fluorescence of pea (Pisum sativum L.) plants in response to ambient ozone at a rural site in Egypt التبادل الغازى والوميض الكلوروفيللى للبازلاء نتيجة للأوزون فى منطقة ريفية بمصر |
|
Subject |
: |
Enviromental sciences |
|
Document Language |
: |
English |
|
Abstract |
: |
Egyptian pea cultivars (Pisum sativum L. cultivars Little Marvel, Perfection and Victory) grown in open-top cham-bers were exposed to either charcoal-filtered (FA) or non-filtered air (NF) for five consecutive years (2009–2013) at a rural site in northern Egypt. Net photosynthetic rates (PN), stomatal conductance (gs), intercellular CO2 (Ci) and chlorophyll fluorescence were measured.
Ozone (O3) was found to be the most prevalent pollutant common at the rural site and is suspected to be involved in the alteration of the physiological parameters measured in the present investigation.
PN of different cultivars were found to respond similarly; decreases of 23, 29 and 39% were observed in the cul-tivars Perfection, Little Marvel and Victory, respectively (averaged over the five years) due to ambient O3.The maximum impairment in PN was recorded in the cultivar Victory (46%) in 2013 when the highest O3 levels were recorded (90 nL L−1). The average stomatal conductance decreased by 20 and 18% in the cultivars Little Marvel and Perfection, respectively, while the average stomatal conductance increased on average by 27% in the cultivar Victory. A significant correlation was found between PN and Ci, indicating the importance of non-stomatal limitations of photosynthesis, especially in the cultivar Victory. The PN vs. Ci curves were fitted to a non-rectangular hyperbolic model.
The actual quantum yield (ΦPSII) and photochemical quenching coefficient (qP) were significantly decreased in the leaves of plants exposed to NF air. Non-photochemical quenching (NPQ) was increased in all cultivars. Exposure to NF air caused reductions in chlorophyll (Chl a) of 19, 16 and 30% in the Little Marvel, Perfection and Victory cultivars, respectively. |
|
ISSN |
: |
0048-9697 |
|
Journal Name |
: |
Science of The Total Environment |
|
Volume |
: |
1 |
|
Issue Number |
: |
14 |
|
Publishing Year |
: |
1435 AH
2014 AD |
|
Article Type |
: |
Article |
|
Added Date |
: |
Tuesday, September 16, 2014 |
|
Researchers
| I.M. Ismail | Ismail, I.M. | Researcher | | |
| J.M. Basahi | Basahi, J.M. | Researcher | | |
| I.A. Hassan | Hassan, I.A. | Researcher | | ihassan_eg@yahoo.com |
|
Files
|
37351.pdf
| pdf | Gas exchange and chlorophyll ?uorescence of pea (Pisum sativum L.) plants in response to ambient ozone at a rural site in Egypt |
|