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Physiological and anatomical disturbances induced by chloride salts in sensitive and tolerant citrus: beneficial and detrimental effects of cations
Author(s) -
RomeroAranda R.,
Moya J. L.,
Tadeo F. R.,
Legaz F.,
PrimoMillo E.,
Talon M.
Publication year - 1998
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1046/j.1365-3040.1998.00349.x
Subject(s) - abscission , photosynthesis , chemistry , potassium , calcium , sodium , salinity , chloride , horticulture , citrus × sinensis , cultivar , botany , biology , orange (colour) , food science , biochemistry , ecology , organic chemistry
In citrus, the relative contributions of chloride and cations to growth disturbances induced by salinity are a matter of controversy. Chloride salts (15 mol m –3 CaCl 2 , 30 mol m –3 CaCl and 30 mol m –3 KCl) reduced growth and gas exchange parameters, increased leaf damage and abscission and produced anatomical disarrangements and mineral imbalances in seedlings of sensitive Carrizo citrange ( Citrus sinensis x Poncirus trifoliata ) and tolerant Cleopatra mandarin ( Citrus reshni ). In both cultivars, Ca 2+ was more beneficial, and K + more detrimental, for growth than sodium. Photosynthesis and growth disturbances were highly correlated ( P ≤ 0·001) with leaf Cl – build‐up. In the sensitive genotype, Cl – was also significantly correlated with several leaf anatomical disarrangements, such as increase in succulence. In comparison with sodium, both calcium and potassium increased leaf Cl – content (up to 25 and 69%, respectively). Protective calcium effects were not linked to improvement of photosynthesis, reduction of leaf anatomical disarrangements, or prevention of Cl – and Na + increases. It is proposed that the ameliorative effects of calcium on citrus grown under salinity are mostly related to reduction of leaf abscission. Collectively, the data suggest a cause–effect relationship between Cl – build‐up and reduced growth, whereas chloride correlations with declines in photosynthesis or increases in succulence appear to be indirect.