Impact of drought stress on photosystem II efficiency and pigment contents in Nitraria schoberi L. Plants
Subject Areas : Journal of Plant EcophysiologyAbolfazl Ranjbar fordoei 1 , Seyyed Ali Mousavi 2
1 - Deputy in research activities / Faculty of Natural Resources and Earth Siences
2 - Student
Keywords: photosynthesis, drought, Fluorescence, pigment, Niter bush,
Abstract :
Some authors distinguished that N. schoberi often used as ruminant feeding systems or used as drought reserve to fill annual feed shortages within grazing systems. Environmental stresses such as drought stress affect plants photosynthetic apparatus directly or indirectly. Several studies on chlorophyll a fluorescence yields base demonstrated that photosystem II (PSII) is highly drought resistance under water stress but photosynthetic, electron transport through PS II is inhibited. Several investigations have shown that the chlorophyll level decreases with aggravated drought stress. Drought stress treatments were prepared on base of soil water potential at field capacity (FC). The treatments were divided into five levels: T1 (FC = 100%), T2 (FC = 80%), T3 (FC = 60%), T4 (FC = 40%) and T5 (FC = 20%). In this study, photosynthetic apparatus of N. schobery, was damaged to a certain extent, as observed from leaf chlorophyll fluorescence parameters such as F0, Fm, Fv, qP and NPQ. A considerable decrease in pigment (Chl. a, Chl. b and carotenoids) content was observed at T4 and continued to T5. Thus, an important conclusion can be drawn from the results achieved through this study. Niter bush is considered to be a drought tolerant species. Our results indicate its ability to maintain high physiological activities when subjected to relatively high levels of drought.