High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress

Tavakkoli, Ehsan and Rengasamy, Pichu and McDonald, Glenn (2010) High concentrations of Na+ and Cl- ions in soil solution have simultaneous detrimental effects on growth of faba bean under salinity stress. Journal of Experimental Botany, 61 (15). pp. 4449-4459. ISSN 0022-0957

Abstract

[Abstract]: Despite the fact that most plants accumulate both sodium (Na+) and chloride (Cl–) ions to high concentration in their shoot tissues when grown in saline soils, most research on salt tolerance in annual plants has focused on the toxic effects of Na+ accumulation. There have also been some recent concerns about the ability of hydroponic systems to predict the responses of plants to salinity in soil. To address these two issues, an experiment was conducted to compare the responses to Na+ and to Cl– separately in comparison with the response to NaCl in a soil-based system using two varieties of faba bean (Vicia faba), that differed in salinity tolerance. The variety Nura is a salt-sensitive variety that accumulates Na+ and Cl– to high concentrations while the line 1487/7 is salt tolerant which accumulates lower concentrations of Na+ and Cl–. Soils were prepared which were treated with Na+ or Cl– by using a combination of different Na+ salts and Cl– salts, respectively, or with NaCl. While this method produced Na+-dominant and Cl–-dominant soils, it unavoidably led to changes in the availability of other anions and cations, but tissue analysis of the plants did not indicate any nutritional deficiencies or toxicities other than those targeted by the salt treatments. The growth, water use, ionic composition, photosynthesis, and chlorophyll fluorescence were measured. Both high Na+ and high Cl– reduced growth of faba bean but plants were more sensitive to Cl– than to Na+. The reductions in growth and photosynthesis were greater under NaCl stress and the effect was mainly additive. An important difference to previous hydroponic studies was that increasing the concentrations of NaCl in the soil increased the concentration of Cl– more than the concentration of Na+. The data showed that salinity caused by high concentrations of NaCl can reduce growth by the accumulation of high concentrations of both Na+ and Cl– simultaneously, but the effects of the two ions may differ. High Cl– concentration reduces the photosynthetic capacity and quantum yield due to chlorophyll degradation which may result from a structural impact of high Cl– concentration on PSII. High Na+ interferes with K+ and Ca2+ nutrition and disturbs efficient stomatal regulation which results in a depression of photosynthesis and growth. These results suggest that the importance of Cl– toxicity as a cause of reductions in growth and yield under salinity stress may have been underestimated.


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Item Type: Article (Commonwealth Reporting Category C)
Refereed: Yes
Item Status: Live Archive
Additional Information: Permanent restricted access to published version due to publisher copyright policy.
Depositing User: epEditor USQ
Faculty / Department / School: Historic - Faculty of Engineering and Surveying - No Department
Date Deposited: 10 May 2011 01:40
Last Modified: 10 Oct 2014 05:37
Uncontrolled Keywords: chloride; faba bean; salt tolerance; sodium
Fields of Research (FOR2008): 07 Agricultural and Veterinary Sciences > 0703 Crop and Pasture Production > 070303 Crop and Pasture Biochemistry and Physiology
05 Environmental Sciences > 0503 Soil Sciences > 050302 Land Capability and Soil Degradation
06 Biological Sciences > 0607 Plant Biology > 060703 Plant Developmental and Reproductive Biology
Socio-Economic Objective (SEO2008): B Economic Development > 82 Plant Production and Plant Primary Products > 8205 Winter Grains and Oilseeds > 820503 Grain Legumes
Identification Number or DOI: doi: 10.1093/jxb/erq251
URI: http://eprints.usq.edu.au/id/eprint/18995

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