Chlorophyll fluorescence performance of sweet almond [Prunus dulcis (Miller) D. Webb] in response to salinity stress induced by NaCl

Abstract

One-year old sweet almond (Prunus dulcis) seedlings were submitted to four levels of salt stress induced by NaCl, namely 0.3, 0.5, 0.7, and 1.0 S m −1 . Effects of salt stress on a range of chlorophyll (Chl) fluorescence parameters (Chl FPs) and Chl contents were investigated in order to establish an eco-physiological characterization of P. dulcis to salinity. Salt stress promoted an increase in F 0 , F s , and F 0 /F m and a decrease in F m , F' m , F v /F m , q P , ΔF/F' m , F v /F 0 , and UQF (rel) , in almost all Chl fluorescence yields (FY) and FPs due to its adverse effect on activity of photosystem 2. No significant changes were observed for quenchings q N , NPQ, and q N(rel) . The contents of Chl a and b and their ratio were also significantly reduced at increased salt stress. In general, adverse salinity effects became significant when the electric conductivity of the nutrient solution (EC n ) exceeded 0.3 S m −1 . The most sensitive salt stress indicators were F v /F 0 and Chl a content, and they are thus best used for early salt detection in P. dulcis. Monitoring of a simple Chl FY, such as F 0 , also gave a good indication of induced salt stress due to the significant correlations observed between the different Chl FYs and FPs. Even essential Chl FYs, like F 0 , F m , F' m , and F s , and mutually independent Chl FPs, like F v /F 0 and q P , were strongly correlated with each other.Additional key words: fluorescence quenching.

Effects of water and nitrogen supply on growth, water-use efficiency and mucilage yield of isabgol (Plantago ovata Forsk)

“…In the present research, we observed that Fv/Fm showed significant differences between the water treatments at given nitrogen supply (Table 4). This is in agreement with most of the data reported in the literature regarding water deficit (Ranjbarfordoei et al, 2006). They found that variable and maximal Chlorophyll fluorescence and fluorescence quenching were not affected by drought stress, and that other fluorescence parameters showed little difference.…”

“…Concomitantly with this decrease the rate of electron transport dropped by about 41 and 44% for I 60 and I 40 at N 180 compared to N 0 . Quantum yield at I 40 was significantly decreased by N addition with no drastically differences between N supplies which revealed the occurrence of a dynamic photo inhibition, which seemed to be effective in protecting the photosynthetic apparatus from the high risk of photo damage occasioned by the superimposed stresses to which the plants were subjected under drought stress conditions (Ranjbarfordoei et al, 2006). In the present research, we observed that Fv/Fm showed significant differences between the water treatments at given nitrogen supply (Table 4).…”

Vegetative growth, compatible solute accumulation, ion partitioning and chlorophyll fluorescence of 'Malas-e-Saveh' and 'Shishe-Kab' pomegranates in response to salinity stress

“…In our experiment, F0 significantly increased with salinity increment, which was in agreement with Ranjbarfordoei et al (2006) in sweet almond. Rising F 0 occurs when plants are exposed to extreme environmental stress, which leads to the structural alteration in PSII (Krause and Weis 1984).…”

“…Chlorophyll (Chl) fluorescence yield can show stress or damage to the photosynthetic apparatus (Glynn et al 2003). Various reports focus on Chl fluorescence parameters in plants subjected to drought (Petsas andGrammatikopoulos 2009, Khaleghi et al 2012), freezing (Percival and Fraser 2001), ozone (Meinander et al 1996), and salinity (Ranjbarfordoei et al 2006, García-Sánchez and Syvertsen 2006, Kalaji et al 2011. Jain and Dass (1988) and Patil and Waghmare (1982) reported that plant height, number of leaves, and stem diameter of pomegranate plants decreased significantly with increasing soil salinity.…”

Rootstock breeding in Prunus species: Ongoing efforts and new challenges

“…These authors also observed a reduced growth of the roots and increased accumulation of sorbitol in leaves. In almond, Ranjbarfordoei et al (2006) showed that the content of chlorophyll and fluorescence parameters in leaves are adversely affected when the electrical conductivity of the irrigation water exceeded 3 dS m -1 . Also working with almond clones under different levels of salinity (0 to 75 mM NaCl), Najafian et al (2008) found that with increased levels of stress, growth of stems, number of internodes, leaf area, fresh and dry weight of roots were reduced.…”