草原毒害草-黄花棘豆种子萌发的影响因素探讨

To understand the germination characteristics of yellow-hair crazyweed (Oxytropis ochrocephala), different temperatures and pregermination treatments were conducted to study the factors that affect seed germination. The results showed that temperature was the most significant factor germination. From 10℃ to 25℃, seed germination rate increased with temperature, with the highest germination rate of 15.3% in 25℃, and the lowest germination rate of 1.3% in 10℃/5℃. Anyhow, germination rate was significantly higher under the condition of constant temperature than that of the corresponding treatments with low temperature in night. With temperature rising, the vigor index of yellow-hair crazyweed was also increased, and the initiatory time of seed germination was shortened and the hard seed rate was decreased. In 10℃/5℃, the vigor index was the lowest of 0.05, with the initiatory time of seed germination of 22.3 d and the hard rates of 97.2%. The influence of pregermination treatments on seed generation was related to temperature. In constant temperature of 25℃/5℃, seed vigor index was significantly improved under seed soaking in cold water, and it also shortened the initiatory time of seed germination; while the germination rate was significantly increased under seed soaking at variable temperature of 10℃. However, the seed germination rate, vigor index, initiatory time of seed germination and hard seed rate were at the same level in other temperatures. Thus, the yellow-hair crazyweed may have little opportunity of quick establishment in alpine grassland, where it has a lower average annual temperature and dramatic temperature fluctuations between days and nights.