Diurnal photosynthesis, water use efficiency and light use efficiency of wheat under Mediterranean field conditions
[ N/A ]
Tarih
2008
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Triveni Enterprises
Erişim Hakkı
info:eu-repo/semantics/closedAccess
Özet
Photosynthesis and transpiration rates of wheat leaves (Triticum aestivum L.) were measured at 30 min intervals under Mediterranean field conditions, using Photosynthesis Monitor system (PM-48M). The dynamics of net photosynthetic rate (PN), transpiration rate (ET), water use efficiency (WUE), light use efficiency (LUE), stomatal conductance (gs), photosynthetically active radiation (PAR), air temperature (T), relative humidity (RH), and atmospheric CO2 concentration (Catm) were quantified at five rainfed wheat sites with the same stages of development (midflowering) along south-to-north and east-to-west transects for eight days in April. Diurnal PN (3.6 to 6.6 ?mol m-2 s -1), PAR (392 to 564 ?mol m-2 sec-1), LUE (0.006 to 0.015) and WUE (0.0001 to 0.011) did not vary significantly across all five wheat sites (p>0.05). PN and ET were strongly coupled and highly correlated with PAR (p<0.001). Best multiple linear regression (MLR) models accounted for 92% of variations in PN as a function of PAR and ET, and 90% in ET as a function of PAR and RH (p<0.001). PN exhibited a peak at mid-morning, and a photosynthetic midday depression under the limiting effects of high evaporative demand. Diurnal variations in WUE and LUE showed a bimodal behavior with the maximum values in early morning and late afternoon. As the impacts of global climate change become increasingly felt, continuous measurements of climate-crop-soil-management interactions under natural conditions play a pivotal role not only in exploring changes in ecophysiological properties of strategic crops for food security such as wheat but also in devising preventive and mitigative management practices to ensure sustained agricultural productivity. © Triveni Enterprises.
Açıklama
Anahtar Kelimeler
Light use efficiency, Photosynthesis, Transpiration, Water use efficiency, Wheat
Kaynak
Journal of Environmental Biology
WoS Q Değeri
Scopus Q Değeri
Q3
Cilt
29
Sayı
3
