吉美静 崔海兰 陈景超 于海燕 张金鹏 李香菊

摘要：长芒苋是我国1985年发现的外来入侵植物，明确长芒苋种子萌發特性，将为其有效防控提供数据支撑。采用室内生物测定方法，对温度、光照、水势、发芽深度等影响长芒苋萌发的关键因子进行研究。结果表明，变温处理可有效提高长芒苋种子的发芽势和萌发率，最适萌发温度为35 ℃/15 ℃变温处理;在35 ℃/15 ℃培养条件下，光照对长芒苋种子的萌发影响不显著;当渗透势为-0.4～-0.2 MPa时，长芒苋种子的萌发率可达82.2%～100%，当渗透势为-0.8 MPa时，仍有36.7%的种子萌发;长芒苋种子的出苗率受播种深度的影响，在播种深度为0.5～1.0 cm时，萌发率最高。由此可见，长芒苋萌发具有广泛的环境适生范围，这也可能是其在我国大面积入侵的生态学基础。

关键词：长芒苋;入侵性杂草;发芽势;发芽率;变温处理

中图分类号：S451  文献标志码：A  文章编号：1003-935X（2021）03-0008-07

Abstract：Amaranthus palmeri，an invasive plant，was first recorded in China in 1985. Clarifying its seed germination characteristics will provide data support for its effective control. Laboratory experiments were conducted to examine the effect of key factors including temperature，light，osmotic stress and burial depth on the seed germination of A. palmeri. The germination potential and germination rate of A. palmeri could be effectively improved in changing temperature，and under the optimum temperature of 35 ℃/15 ℃ day/night，its seed germination was not affected significantly by light. Seed germination rate reached 82.2%～100% when the osmotic potential was -0.4～- 0.2 MPa and 36.7% of the seeds still germinated when the osmotic potential was -0.8 MPa. The optimum burial depth for highest germination rate was 0.5～1.0 cm then decreasing with burial depth. Therefore，A. palmeri was strongly adapted to different environments providing it with the ability to its large-scale invasion in China.

Key words：Amaranthus palmeri;invasive weed;germination potential;germination rate;changing temperature

杂草种子萌发与环境条件的关系是杂草生态学研究的重要组成部分。温度、光照、水分、播种深度是影响种子萌发和出苗的重要因素。由于杂草长期适应自然环境下温度的波动变化，大部分杂草种子在变温条件下更易萌发。如矢车菊[1]和棒头草[2]等在变温条件下，萌发率更高。有报道认为，苋属杂草反枝苋、绿穗苋、长芒苋、西部苋和糙果苋等经过变温处理后，可以有效提高其萌发率[3]。光照也是种子萌发过程中的重要环境因子。光暗交替有利于一些杂草种子的萌发。例如，在昼夜交替的条件下，稗草[4]、藜[5]、野西瓜苗[6]种子的萌发率均显著提高。……