If You Use a Screen ReaderThis content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
CORRESPONDENCE BETWEEN NI TOLERANCE AND HYPERACCUMULATION IN STREPTANTHUS (BRASSICACEAE)
Robert S. Boyd, Michael A. Wall and James E. Watkins, Jr.
Vol. 47, No. 2 (APRIL-JUNE 2000), pp. 97-105
Published by: California Botanical Society
Stable URL: https://www.jstor.org/stable/41425351
Page Count: 9
You can always find the topics here!Topics: Serpentine soils, Hyperaccumulators, Root growth, Germination, Martens, Allelopathy, Endemic species, Agricultural soils, Soil ecology
Were these topics helpful?
Select the topics that are inaccurate.
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
Preview not available
Nickel hyperaccumulation may be associated with increased Ni tolerance for some plant species that grow on serpentine soils. We contrasted the Ni tolerance of three species: a Ni hyperaccumulator (Streptanthus polygaloides A. Gray) endemic to serpentine soil, a congeneric non-hyperaccumulator also endemic to serpentine soil (S. breweri A. Gray), and a species from the same family but not adapted to serpentine soil (Brassica oleracea L.). We assessed Ni tolerance by measuring germination and radicle elongation in test solutions varying in Ni⁺² content. By both approaches, Ni tolerance was greatest for the hyperaccumulator, intermediate for the non-hyperaccumulator, and least for the unadapted species. A soil-based test of root elongation, using S. polygaloides and B. oleracea with two serpentine soils and one non-serpentine soil, showed a significant species-by-soil interaction. Root elongation of B. oleracea was inhibited in serpentine soil, whereas S. polygaloides showed reduced root elongation in non-serpentine soil. We concluded that these results are consistent with the hypothesis that Ni hyperaccumulation is a metal tolerance mechanism adopted by some species native to serpentine soils. These results also are consistent with other ecological functions of Ni hyperaccumulation, such as the elemental allelopathy or microsite tolerance hypotheses.
Madroño © 2000 California Botanical Society