The effects of temperature upon seed germination in Festuca pratensis var. apennina.
The effects of temp. on seed dormancy and germination were studied in 11 populations of tetraploid F. pratensis var. apennina from the Italian Alps and Apennines. 3 populations from the Apennines had a smaller cold requirement to break dormancy. There was no correlation between cold requirement to break dormancy and the alt. from which the population was collected. Populations from the Apennines germinated over a wider range of temp. than those from the Alps. Populations from lower alt. had a lower opt. temp. for germination than those from high alt. The seeds of all populations had a high opt. germination temp. (c. 27 deg C) when given only a short period of cold treatment. As the period of exposure to low temp. was increased, the range at which germination occurred extended to lower temp. The relationship between opt. germination temp. and the period of exposure to low temp. may provide an adaptive mechanism which ensures survival at high alt.