Seed Germination Characteristics of Ornamental Grass Eragrostis spectabilis (Poaceae)

Eragrostis spectabilis is used as an ornamental grass in China, but some researches reported that it had high potential risk of becoming invasive. Usually successful exotic weeds had strong reproduction ability. But for now, germination characteristics of E.spectabilis seeds have not been reported. Effects of temperature, light, water stress and soil depth on E.spectabilis seeds germination were studied by petri dish and pot experiments. The results showed that using germination percentage and germination index as evaluated indicators, the optimum germination temperature of E.spectabilis was 35 ℃. According to the seed germination thermal model(T, ℃), the germination temperature range was between 17.7 ℃ and 43.2 ℃, with the best temperature of 39.2 ℃. Light was favorable for seed germination, the germination percentage was relatively higher under continuous light condition than continuous dark condition. PEG6000-simulated water stress significantly inhibited the germination. When water potential decreased to -0.8 Mpa, seeds could not germinate. The soil depth of 0.5 cm was ideal for germination and the germination percentages from 0-1 cm were more than 60%. The germination percentage decreased significantly with the increase of soil depth between 1-4 cm.