Effects of temperature, light, and PEG on seed germination in different ecotypes of Achnatherum inebrians

The percent seed germination, germination index, radical length, and plumule length of Achnatherum inebrians seeds and seedlings of the Yuzhong and Alax ecotypes were measured in treatments with different temperatures (10 ℃/20 ℃、15 ℃/25 ℃和20 ℃/30 ℃, all under a 12/12 h light/dark cycle), light conditions (24 h light and 24 h dark), and PEG (polyethylene glycol) concentrations (0, –0.3, –0.6, and –0.9 MPa). The results showed that 15 ℃/25 ℃ was the most suitable temperature for the seed germination of both Achnatherum inebrians ecotypes. The generation rate and index, radical length, and plumule length of these two ecotypes significantly decreased under treatments with increasing PEG stress levels. Under the combined action of all three factors, the radical length and plumule length of the Alax ecotype of Achnatherum inebrians were greater than those of the Yuzhong ecotype.