Effects of Sulfide on Growth and Dimethylsulfoniopropionate (DMSP) Concentration in Spartina Alterniflora

Abstract

The effects of sulfide on growth and dimethylsulfoniopropionate (DMSP) concentration in Spartina alterniflora were studied in greenhouse cultures. Spartina plants were maintained in sand-filled pots and supplemented with a balanced nutrient mixture and 1 g/1 of NaCl. After they were well established, plants were separated into four treatment groups that were maintained in different sulfide concentrations ranging from 0 to 2 mM Na2S for 5 weeks in March and April, 1994. Relative growth rates, determined from weekly plant heights, final dry weights, and final DMSP concentrations in tissues were measured. The results indicated that sulfide concentrations in the neighborhood of 1 mM were optimal for growth. Sulfide treatment affected leaf growth, but not root growth. The maximum relative growth rate (2.0±0.3% day-1) was found in the 1 mM treatment, while the minimum growth rate (0.5±0.2% day-1) was found in the 0 mM treatment. Mean stem height reached 64 cm in the 1 mM treatment and was 47 cm in the 0 mM treatment. Final stem weights were 1.4±1.2 and 0.8±0.65 g/pot in the 2 and 0 mM treatments, respectively. In general, growth at 2 mM was equivalent to that in the 1 mM treatment. The sulfide treatments had marginally significant effects on the DMSP concentration in leaf tissues and no effect in roots. Data on sulfide distributions in pore water in several marsh sites suggest that there is no consistent relationship between Spartina production and sulfides. The results demonstrate that the relationship between Spartina growth and sulfides is complex.