Competition between diploid and derivative autotetraploid Dactylis glomerata L. from Galicia. Implications for the establishment of novel polyploid populations

Authors

  • N. O. MACEIRA,

    1. Centre Louis Emberger, C.E.F.E., C.N.R.S., B.P. 5051, F.34033 Montpellier Cedex 1, France
    Search for more papers by this author
    • *

      Facultad de Ciencias Agrarias, Universidad Nacional de Mar del Plata, CC 276, 7620 Balcarce, Argentina.

  • P. JACQUARD,

    1. Centre Louis Emberger, C.E.F.E., C.N.R.S., B.P. 5051, F.34033 Montpellier Cedex 1, France
    Search for more papers by this author
  • R. LUMARET

    Corresponding author
    1. Centre Louis Emberger, C.E.F.E., C.N.R.S., B.P. 5051, F.34033 Montpellier Cedex 1, France
      To whom correspondence should be addressed.
    Search for more papers by this author

To whom correspondence should be addressed.

SUMMARY

The competitive ability of a tetraploid, and its morphologically indistinguishable progenitor diploid Dactylis glomerata L., from Galicia (Spain), was tested in a two-year study, using isolated plants and the same individuals grown at two densities (16 and 36 plants per pot, respectively). Inverse linear regression equations were used to quantify the response of the different ploidy levels (hereafter cytotypes) to density. For the diploids, inter-cytotype competition coefficients were significantly higher than intra-cytotype coefficients. The substitution rate increased from 1. in the first year to 3.9 in the second year, when most of the diploids failed to flower and some died. The competitive superiority of the tetraploids was associated with higher mean tiller weight, particularly in the mixed cultures. The tetraploids also had heavier seeds and faster leaf production in early spring, and they flowered earlier than the diploids. Several of these differences between cytotypes appear to be due to differences in ploidy level and may play a major role in the establishment of the tetraploids in Galician pastures, where competition is high.

Ancillary