Raziyeh Robatjazi; Parto Roshandel; Sa’dollah Hooshmand
Abstract
In the present study, improvement of salt tolerance in basil (as a salt-sensitive plant) was investigated through silicon (Si) nutrition. Basil plants were subjected to silicon (0, 3 mM) and salinity (0, 50, 100, 150 and 200 mM NaCl) for a duration of one month. Salt stress significantly decreased the ...
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In the present study, improvement of salt tolerance in basil (as a salt-sensitive plant) was investigated through silicon (Si) nutrition. Basil plants were subjected to silicon (0, 3 mM) and salinity (0, 50, 100, 150 and 200 mM NaCl) for a duration of one month. Salt stress significantly decreased the biomass of basil. Si supplement (3 mM) resulted in a considerable increase (averagely +135%) in the biomass of salinized plants. Salt stress significantly decreased photosynthetic pigments concentrations, but Si supplement improved total chlorophyll concentration (averagely up to +217% compared to salinized plants). This improvement in pigment concentrations also occurred for carotenoids content (+123%). Salinity increased lipid peroxidation and H2O2 level in the aerial parts of the basil plants, but Si decreased lipid peroxidation (-49.1%) and H2O2 content (-29%) under salinity condition. Results showed salinity (alone) or together with Si, increased the level of polyphenols and also the level of radical scavenging activities in the aerial parts of basil but this effect was much more in plants co-treated with Si and salinity. Si nutrition increased the activity of SOD, APX and GPX in response to salt stress, but it did not affect CAT activity. Overall, Si supplement could induce salt tolerance in basil plants by improving photosynthesis, membrane integrity, and detoxification of toxic radicals. Furthermore, silicon increased the medicinal properties of basil via elevating its antioxidant capacity under salt stress.
Hamid Alipour
Abstract
Understanding mechanisms of salt tolerance, physiological responses to salt stress, and screening genotypes for breeding programs are important scientific issues remained to be investigated in pistachio. Therefore, current study was carried out to investigate response of different pistachio cultivars ...
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Understanding mechanisms of salt tolerance, physiological responses to salt stress, and screening genotypes for breeding programs are important scientific issues remained to be investigated in pistachio. Therefore, current study was carried out to investigate response of different pistachio cultivars (G1, G2, Kaleghochi and UCB1) to salinity treatments (0.6 as control, 10, 20 dS m-1 using saline underground water) as a factorial experiment based on randomized complete block design with three replications in greenhouse of Iranian Pistachio Research Institute (Rafsanjan) in 2014-2015. Some physiological and nutrition properties of the pistachio cultivars measured in this study. Results showed decreased stomatal conductance, photosynthesis rate, chlorophyll content, and Fv/Fm in response to salinity treatments. The main cause of these changes was related to the altered ion contents along with the competition among ions for being absorbed by plant. Despite of sufficient amount of potassium in the soil, high concentrations of sodium and other associated elements such as calcium and magnesium decreased the ability of pistachio plants to absorb adequate amount of vital ions such as potassium. As a result of sodium accumulation and deficiency of potassium, K+/Na+ ratio was decreased in pistachio leaves. Consequently, toxicity of sodium ions in the plant cells reduced stomatal conductance and the rate of photosynthesis. Comparison between cultivars showed that for the most of the traits the difference between control and moderate salinity (10 ds m-1) in all cultivars was not significant. However, G2 cultivar showed higher ability to accumulate potassium and absorbed lower concentration of sodium, calcium, and magnesium under sever salinity treatment (20 ds m-1). These result suggested that G2 could be considered as a potential tolerant cultivar for cultivation in saline area.
