几种生态因子对菊科外来入侵植物春飞蓬种子萌发的影响

The Influences of Some Ecological Factors on the Seed Germination of Erigeron philadelphicus, an Invasine Alien Plant in Asteraceae

在实验室条件下,测定了不同光照长度、pH值、渗透势、盐浓度等各种生态因子对春飞蓬种子萌发的影响.结果表明,在0L/24D,8L/16D,12L/12D和16L/8D等四个光照长度条件下,春飞蓬种子的萌发率之间没有显著差异.在pH6到pH8的环境中春飞蓬种子的萌发率均超过0.30,在pH7时萌发率最高,达0.51±0.05;在pH4和pH5的酸性环境和pH9和pH10的碱性环境中,春飞蓬种子均不能萌发.种子对渗透势浓度的变化敏感,在-0.05Mpa及更低的渗透势浓度下,春飞蓬种子的萌发率比对照(0Mpa)显著降低.春飞蓬种子能在适度的盐浓度(0.05mol/L到0.10mol/L)条件下萌发,在NaCl浓度为0.15mol/L及以上时几乎不能萌发.

Under the laboratory conditions, it is studied that the influences of light, pH, osmotic potential and salin- ity on the seed germination of Erigeron philadelphicus, an invasine alien plant in Asteraceae. The result showed that there were no significant differences in the seed germination rates among different light lengths of 0L/24D, 8L/ 16D, 12L/12D and 16L/8D. The seed germination rates were all over 0.30 under pH6 to pH8, and were greatest for pH7 （0.51±0.05）, but there was no seed germination either in the acidic environment of pH4 and pH5 or in the al-kaline environment of pH9 and pill0. Seed germination was sensitive to osmotic potentials and the germination rates decreased significantly when osmotic potentials were -0.05 Mpa or lower than it. Seeds could germinate in moderate NaC1 solution concentrations （0.05mol/L to 0.10mol/L）. Almost no seeds could germinate in a NaC1 solu-tion at a concentration of 0.15mol/L or higher than it.