Relative aluminium tolerance of ten species of Graminae

Abstract

Ten species (28 genotypes) of Graminae were screened in low ionic strength (2.7x10^‐3 M) solution culture for aluminum (Al) tolerance. The Al³⁺ activity (μ?) that reduced yield by 50% (Al_RY50) was determined. The species, in order of increasing Al tolerance (with Al_RY50 for the tops shown in parenthesis) were Panicum miliaceum (0.4) < Bromus inermis (1.4) < Phleum pratense (2.3) = Bromus stamineus (2.5) = B. sitchensis (2.5) < Lolium perenne (3.3) = L. x boucheanum (3.9) < Oryza sativa (17). An Al_RY50 could not be determined for Agrostís castellana or Zea mays although both were tolerant (Al_Ry5O > 20 μM and > 10 μ?, respectively). Plant element concentrations were determined in five species. Increasing solution Al concentrations increased Al and decreased magnesium (Mg) and potassium (K) in the tops and roots, decreased calcium (Ca) in the tops, and increased phosphorus (P) in the roots.