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Effect of sodium chloride on growth and nitrogenase activity in seedlings of Myrica cerifera L.
Author(s) -
SANDE EVE,
YOUNG DONALD R.
Publication year - 1992
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.1992.tb01074.x
Subject(s) - nitrogenase , salinity , dry weight , horticulture , transpiration , relative growth rate , botany , biology , leghemoglobin , nitrogen fixation , stomatal conductance , photosynthesis , sodium , zoology , root nodule , chemistry , growth rate , ecology , bacteria , geometry , mathematics , organic chemistry , genetics
summary The actinorhizal shrub, Myrica cerifera L., is widespread in coastal areas where it may be exposed to variable saline conditions. In growth chamber studies, 5‐month‐old seedlings remained viable during exposure to 150 mM NaCl for 35 d, though concentrations above 50 mM significantly depressed plant and root nodule growth. Concentrations of NaCl above 50 mM also depressed stomatal conductance to water vapour diffusion and net photosynthetic rates. Relative to control plants, nitrogenase activity per g dry weight of nodules decreased for 21 d in plants subjected to a range of NaCl concentrations. By day 35. plants exposed to 25 and 50 mM NaCl had recovered some nitrogenase activity relative to the controls, whereas plants receiving 100 and 150 mM had not. At 35 d, plants treated with 150 mM NaCl had a rate of N 2 fixation per g dry weight of nodule tissue 26% of that in control plants. However, no mortality had occurred, and full recovery followed the conclusion of the experiment. Thus, although periodic natural increases in salinity from sea spray or storm overwash may not lead to plant mortality, growth and N 2 fixation will be significantly decreased in M. cerifera .