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黄顶菊是一种入侵性极强的外来杂草,其种子对环境的适应是其成功入侵的前提。通过室内条件下黄顶菊种子的物理特性、环境因子对其种子萌发及幼苗生长影响等方面的研究,可为探讨黄顶菊快速蔓延的原因与揭示黄顶菊成功入侵机制提供理论依据。结果表明,黄顶菊种子极多而轻与黄顶菊大面积扩散密切相关,温度、光照和种子埋藏深度是决定黄顶菊种子萌发的关键因素。黄顶菊种子萌发的温度范围为5～40℃,25℃最适于种子的萌发,25～35℃条件下有利于幼苗的生长;黄顶菊种子是光敏感型种子,在土壤表面的萌发率最高(74.44%),大于3cm的深层土壤中则不能萌发;pH对黄顶菊种子的萌发影响不明显,但其幼苗在酸性条件下生长较好;黄顶菊种子的萌发能忍受一定的盐胁迫和干旱胁迫,但随着胁迫程度的加重,根长和苗长逐渐降低,50%的土壤含水量对黄顶菊种子萌发和幼苗生长比较适宜。
Flaveria bidentis is a highly invasive alien weed whose adaptation to the environment is the prerequisite for its successful invasion. The research on the physical properties of flaveria bidentis and the influence of environmental factors on its seed germination and seedling growth under indoor conditions may provide the theoretical basis for exploring the reasons for the rapid spread of flaveria bidentis and revealing the success mechanism of flaveria. The results showed that the seedlings of Flaveria bidentis were extremely light and light, which was closely related to the large-scale diffusion of Flaveria bidentis. The temperature, light and seed burial depth were the key factors determining the seed germination of Flaveria bidentis. Flaveria bidentis seeds germinated in the temperature range of 5 ~ 40 ℃, and 25 ℃ was the most suitable for seed germination. Under the condition of 25 ~ 35 ℃, seedling growth was favored. Flaveria bidentis seeds were light-sensitive seeds with the highest germination rate on soil surface (74.44 %), And deeper than 3 cm could not germinate. PH had no obvious effect on the germination of Flaveria bidentis, but the seedlings grew well under acidic conditions. The seed germination of Flaveria bidentis could tolerate a certain amount of salt stress and drought stress, The aggravation of stress, root length and seedling length decreased gradually, and 50% soil moisture content was more suitable for the seed germination and seedling growth of flaveria.