Maryam Chavoushi; Khosrow Manoochehri Kalantari; Mohamad Javad Arvin
Abstract
Salinity stress is one of the main limiting factors for optimum agricultural productivity of safflower, Carthamus tinctorius L., in arid and semi-arid regions. It could leads to significant changes in plant biochemical, physiological, and growth traits. Salinity induced endogenous rise in jasmonic acid ...
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Salinity stress is one of the main limiting factors for optimum agricultural productivity of safflower, Carthamus tinctorius L., in arid and semi-arid regions. It could leads to significant changes in plant biochemical, physiological, and growth traits. Salinity induced endogenous rise in jasmonic acid and its methyl esters (MeJA) has been reported. In the present study, effects of salinity stress (6 and 12 ds m-1) and the exogenous application of MeJA (0.1 and 0.5 mM) on the leaf number, shoot fresh weight, shoot length, chlorophyll a/b, soluble sugar, proline, and malondialdehyde (MDA) contents were investigated in two safflower varieties (Isfahan and IL111). Salinity stress negatively affected the growth of both varieties. Lipid peroxidation was not observed in Isfahan variety, but it significantly increased in the salinity resistant safflower, IL111. Soluble sugar and proline as the important osmoprotectants and free radical scavengers were elevated by salinity stress. Exogenous application of MeJA to the salinity stress-imposed plants slightly improved the growth due to inductions in the rate of photosynthesis; however, MeJA application impaired the growth of non-stressed plants because of induction of stomatal closure and as a result reduced photosynthesis.
Neda Aghajani; Mehrdad Jafarpour
Abstract
This study was conducted to investigate the effects of different silicon supplements and postharvest treatments on growth and yield of gerbera in a greenhouse experiment. Silicon supplements were including potassium silicate at three concentrations (0, 140 and 200 mg L−1), sodium silicate at three ...
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This study was conducted to investigate the effects of different silicon supplements and postharvest treatments on growth and yield of gerbera in a greenhouse experiment. Silicon supplements were including potassium silicate at three concentrations (0, 140 and 200 mg L−1), sodium silicate at three concentrations (0, 50 and 100 mg L−1) and rice hull ash (RHA) at three concentrations (0, 50 and 100 mg L−1). Also, postharvest treatments were including sucrose, salicylic acid (200 and 400 mg L−1), methyl jasmonate (15 and 25 mg L−1) and distilled water (as control). The application of potassium silicate, RHA and sodium silicate led to decrease in dry weight of flower. Shoot length and diameter were substantially higher in 140 mg L−1 potassium silicate than those in control treatment. The maximum inflorescence diameter was observed in rice husk ash (50 mg L−1). Capitulum diameter was far greater in sodium silicate at 50 mg L−1 compared to other treatments. Vase life of gerbera flower was greater in 400 mg L−1 salicylic acid and 15 mg L−1 methyl jasmonate than in control treatment. The maximum inflorescence diameter was observed in 400 mg L−1 salicylic acid. This study confirmed that the studied sources of Si, salicylic acid and methyl jasmonate increased marketable quality of cut gerbera flowers.