Effects of NaCl and Supplementary Potassium on Gas Exchange, Ionic Content, and Growth of Salt-Stressed Strawberry Plants

2 Strawberry is listed as the most salt sensitive fruit crop in comprehensive salt tolerance data bases. Recently, concerns have arisen regarding declining quality of irrigation waters available to coastal strawberry growers in southern and central California. Over time, the waters have become more saline, with increasing sodium (Na + ) and chloride (Cl − ). Due to the apparent extreme Cl − sensitivity of strawberry, the rising Cl − levels in the irrigation waters are of particular importance. In order to establish the specific ion causing yield reduction in strawberry, cultivars 'Ventana' and 'Camarosa' were grown in twenty-four outdoor sand tanks at the ARS-USDA U. S. Salinity Laboratory in Riverside, CA and irrigated with waters containing a complete nutrient solution plus Cl − salts of calcium (Ca 2+ ), magnesium (Mg 2+ ), Na + , and potassium (K + ). Six salinity treatments were imposed with electric conductivities (EC) = 0. 835, 1.05, 1.28, 1.48, 1.71, and 2.24 dS m −1 , and were replicated four times. Fresh and dry weights of 'Camarosa' shoots and roots were significantly higher than those of 'Ventana' at all salinity levels. Marketable yield of 'Camarosa' fruit decreased from 770 to 360 g/plant as salinity increased and was lower at all salinity levels than the yield from the less vigorous 'Ventana' plants. 'Ventana' berry yield decreased from 925 to 705 g/plant as salinity increased from 0.835 to 2.24 dS m −1 . Relative yield of 'Camarosa' decreased 43% for each unit increase in salinity once irrigation water salinity exceeded 0.80 dS m −1 . Relative 'Ventana' yield was unaffected by irrigation water salinity up to 1.71 dS m −1 , and thereafter, for each additional unit increase in salinity, yield was reduced 61%. Both cultivars appeared to possess an exclusion mechanism whereby Na + was sequestered in the roots, and Na + transport to blade, petiole and fruit tissues was limited. Chloride content of the plant organs increased as salinity increased to 2.24 dS m −1 and substrate Cl increased from 0.1 to13 mmol c L −1 . Chloride was highest in the roots, followed by the leaves, petioles and fruit. Based on plant ion relations and relative fruit yield, we determined that, over the range of salinity levels studied, specific ion toxicity exists with respect to Cl − , rather than to Na + ions, and, further, that the salt tolerance threshold is lower for 'Camarosa' than for 'Ventana'.

Section: Downloaded By [Northeastern University] At 19:18 02 January mentioning

confidence: 96%

Growth, Yield, and Ion Relations of Strawberry in Response to Irrigation With Chloride-Dominated Waters

Suarez¹,

Grieve²

2013

“…In this study, the pigments in PT1 seedlings under salt stress were maintained using 11.8 mM KNO 3 pre-treatment, leading to enhanced chlorophyll fluorescence, resulting in growth improvement. The application of potassium nitrate (KNO 3 ) has been reported as an effective way to counteract salt stress in sugarcane (Ashraf et al, 2010); winter wheat (Zheng et al, 2008), bell pepper (Kaya et al, 2003), strawberry (Khayyat et al, 2009), Lagenaria siceraria (Ahmad and Jabeen, 2005), and cucumber (Akinci and Simsek, 2004).…”

Section: Figurementioning

confidence: 98%

“…Similarly, the available water in 'JN17' salt-sensitive winter wheat, was maintained by the application of 11 mM potassium nitrate (KNO 3 ) (Zheng et al, 2008). Photosynthetic pigments are protected by the (Kaya et al, 2003), K 2 SO 4 (Chartzoulakis et al, 2006;Akram et al, 2009;Khayyat et al, 2009) and potassium hydroxide (KOH) (Akram et al, 2007). In this study, the pigments in PT1 seedlings under salt stress were maintained using 11.8 mM KNO 3 pre-treatment, leading to enhanced chlorophyll fluorescence, resulting in growth improvement.…”

Section: Figurementioning

confidence: 99%

“…Exogenous potassium applications, such as potassium chloride (KCl), potassium nitrate (KNO 3 ), monopotassium phosphate (KH 2 PO 4 ), and potassium sulfate (K 2 SO 4 ) fertilizers, are well established for aiding nutrient uptake, water use efficiency, photosynthesis and growth performance in order to reduce salt stress (Kaya et al, 2003;Akinci and Simsek, 2004;Neid and Biesboer, 2005;Collins et al, 2008;Akram et al, 2009;Khayyat et al, 2009). The application of exogenous potassium fertilizers, which alleviates salt damage by enhancing K + uptake and reducing Na + uptake, leading to a decrease in the sodium (Na + )/K + ratio, has been reported on in many crop plants, such as pepper (Kaya et al, 2003), sunflowers (Akram et al, 2009), ryegrass (Tabatabaei and Fakhrzad, 2008), cucumbers (Akinci and Simsek, 2004), strawberries (Khayyat et al, 2009) and rice (Cha-um et al, 2010), and results in the conservation of membrane stability and impediment of the factors retarding growth in plants exposed to salt stress. Therefore, the aim of this research was to investigate the improvement of salt tolerance in PT1 rice seedlings grown with the exogenous application of KNO 3 , prior to exposure to salt stress.…”

Section: Introductionmentioning

confidence: 98%

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Exogenous Application of Potassium Nitrate to Alleviate Salt Stress in Rice Seedlings

Siringam

Juntawong

Cha–um

et al. 2013

2 Overall growth characteristics of many plant species cultivated in soil affected by salinity could be alleviated by the application of potassium nitrate (KNO 3 ) to the soil. The aim of this research was to investigate salt-tolerance in a salt-sensitive rice cultivar, 'Pathumthani 1' (PT1), in response to the exogenous application of 11.8 mM KNO 3 , in comparison to 'Homjan' (HJ), a salt tolerant cultivar. Water potential (ψ w ) in both the roots and leaves of PT1 seedlings under salt stress dropped significantly, while it was maintained in PT1 pretreated with KNO 3 , and similarly in HJ. The reduction of leaf water potential was positively related to total chlorophyll degradation, leading to diminished chlorophyll fluorescence, directly affecting growth in plants exposed to salt stress. In salt-sensitive PT1, the application of 11.8 mM KNO 3 improved salt-tolerance via the conservation of water use efficiency, the maintenance of photosynthetic pigments, enhancement of chlorophyll a fluorescence, and stimulation of growth characters.

“…Seed germination is an important and vulnerable stage in the life cycle of terrestrial angiosperms and determines seedling establishment and plant growth. Despite the importance of seed germination under salt stress (Ungar, 1995), the mechanism (s) of salt tolerance in seeds is relatively poorly understood, especially when compared with the amount of information currently available about salt tolerance physiology and biochemistry in vegetative plants (Hester et al, 2001;Hu et al, 2005;Kanai et al, 2007;Khayyat et al, 2009). Salinity affects seed germination through osmotic effects (Bliss et al, 1986), ion toxicity (Hampson and Simpson, 1990) or combination of them (Huang and Redmann, 1995).…”

Section: Introductionmentioning

confidence: 98%

Seed Germination of Basil and Cress Under NaCl and Boron Stress

Khayyat

Moradinezhad

Safari

et al. 2014

Self Cite

2 The present research was conducted to evaluate the effects of salinized water with boron and sodium chloride (NaCl) on seed germination of basil and cress. Treatments were: boron solution (25 and 50 mM), NaCl solution (25 and 50 mM) and distilled water as control. The highest germination percentage and mean daily germination of both plants were obtained in boron 25 mM. The highest mean germination time of basil and the day of 50% emergence of basil and cress were found in boron 50 mM. Radicle length of basil was reduced by increment of all salinity treatments; however, the highest cress radicle length was observed in 50 mM NaCl. It is concluded that these plants can tolerate salinized water during the germination stage to some extent, however, the cress show more tolerance to these salinities than basil.