تفاصيل الوثيقة

نوع الوثيقة : مقال في مجلة دورية 
عنوان الوثيقة :
Photosynthetic efficiency and pigment contents in alfalfa (Medicago sativa) seedlings subjected to dark and chilling conditions
Photosynthetic efficiency and pigment contents in alfalfa (Medicago sativa) seedlings subjected to dark and chilling conditions
 
الموضوع : علم النبات 
لغة الوثيقة : الانجليزية 
المستخلص : The functional activities of the photosynthetic apparatus of alfalfa (Medicago sativa L.) was investigated after 24 h of dark chilling treatment at 10°C and after 48 h recovery period at 25°C and 420 μmol m -2 S-1. Dark chilling limits photosynthesis due to chilling-associated oxidative damage, which enhanced the production of active oxygen species (AOS). Dark chilling treatment resulted in a significant reduction in the CO2 assimilation rate and decreased stomatal conductance. Stomatal limitation was largely responsible for the inhibition of CO2 assimilation generated by affections in the PSII functioning and also in the Calvin cycle. Photosynthetic parameters and chlorophyll fluorescence analyses showed the same degree of inhibition during the dark chilling period. However, chlorophyll fluorescence analysis showed an increase in the process of energy dissipation in the dark chilled leaves. In addition, leaves showed a significant decrease in chlorophyll a:b ratio and higher carotenoids-to-total chlorophyll ratio providing photoprotection. Under recovery, leaves recovered photosynthetic activity thus diminishing the potential power for AOS generation. 
ردمد : 1560-8530 
اسم الدورية : International Journal of Agriculture and Biology, Volume 10, Issue 3, 2008, Pages 306-310 
المجلد : 10 
العدد : 3 
سنة النشر : 2008 هـ
2008 م 
عدد الصفحات : 5 
نوع المقالة : مقالة علمية 
تاريخ الاضافة على الموقع : Thursday, October 15, 2009 

الباحثون

اسم الباحث (عربي)اسم الباحث (انجليزي)نوع الباحثالمرتبة العلميةالبريد الالكتروني
سميره عمر سعيد بافيلSameera Omar Bafeelباحثدكتوراهsbafil@kau.edu.sa
Ibrahim, M.MIbrahim, M.Mباحثدكتوراه 

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