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Interactions between diurnal temperature fluctuations and salinity on expansion growth and water status of young tomato plants
Author(s) -
McCALL D.,
ATHERTON J. G.
Publication year - 1995
Publication title -
annals of applied biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.677
H-Index - 80
eISSN - 1744-7348
pISSN - 0003-4746
DOI - 10.1111/j.1744-7348.1995.tb06664.x
Subject(s) - salinity , biology , osmotic pressure , shoot , growth rate , horticulture , nutrient , botany , ecology , geometry , mathematics
Summary Expansion growth is limited if the difference between day and night temperature (DIF) is negative. Growth is also limited high salinity. Expansion growth of tomato seedlings was studied under day/night temperatures of 16/24°C and 24/16°C, and nutrient solution salinities of 3 and 15 mS cm ‐1 to ascertain whether interactions exist between the two stress forms. Water status was also studied in order to assess possible mechanisms of growth retardation. A significant interaction between DIF and salinity was found for all recorded growth variables. Hypocotyl length, plant height, leaf area and fresh and dry weight were lower at negative DIF than at positive, the reduction being greater at low salinity than at high. Increased salinity also reduced growth, more so at positive DIF than at negative. Growth reduction at negative DIF was accompanied increased shoot water and osmotic potentials. Pressure potential was unaffected DIF. Growth reduction at high salinity was accompanied reduced water and osmotic potentials. Pre‐dawn pressure potential was increased at high salinity, whereas no effect of salinity on pressure potential at midday was found. The differences in effects on water status between the two stress forms may suggest differing mechanisms of growth retardation.