三叶鬼针草根系分泌物对井栏边草配子体生长和发育的影响
Effect of Root Exudates of Bidens pilosa on Growth and Development of Gametophyte of Pteris multifida

以井栏边草配子体和外来入侵物种三叶鬼针草根系分泌物为研究材料，验证三叶鬼针草根系分泌物对井栏边草配子体的化感作用。以5个梯度的根系分泌物对配子体进行培养，通过选取死亡率、假根长度、生物量和孢子转化率4个指标，同时对配子体进行定期记录并在第10天做扫描电镜观察，研究井栏边草配子体在三叶鬼针草根系分泌物处理下的生长情况。结果显示，根系分泌物体积分数为12.5%、25%、50%以及100%的处理组，致死率分别为 10.0%、25.3%、48.1%和88.3%；同样,随着处理体积分数升高而下降的还有生物量和孢子转换率，其中生物量和孢子转换率体积分数100%处理组相对12.5%的处理组减少23.8%和48.7%。较短假根对于根系分泌物的影响较小，而较长假根的变化较为显著，呈现随着处理体积分数升高而显著下降的趋势。在扫描电镜的观察中，配子体的假根生长受到影响较大，并且随体积分数的升高，假根破坏率较大，同时配子体的细胞出现死亡和破裂。说明三叶鬼针草根系分泌物对井栏边草配子体的生长和发育具有抑制作用。
Taking gametophyte of Pteris multifida and root exudates of Bidens pilosa as materials, The effects of allelopathy of the root exduates of Bidens pilosa on gametophyte of Pteris multifida were tested in this research. Five grades of root exduates were used to culture the gametophyte. The study of the growth and development of gametophyte of Pteris multifida was conducted in four indexes such as death rate, length of the rhizoid, biomass and the conversion rate of spore ,as well as the regular observation and scanning electron microscope (SEM) on 10th day. The results showed that the death rate of gametophyte under 12.5%, 25%, 50% and 100% treatment is 10.0%, 25.3%, 48.1% and 88.3% respectively. Meanwhile, biomass and the conversion rate of spore also decrease with the increase of the root exduates concentration, biomass and the conversion rate of spore of 100% treatment reduce 23.8% and 48.7% to 12.5% treatment. The shorter rhizoids have little feedback to the exduates, while the longer ones represent more significant to the increase of the root exduates. In the observation of SEM, the growth of rhizoids is affected more by the exduates, and with the increase of the exduates, the damage raising up, as well as the death and rupture of the gametophyte cells. The results also indicated root exudates of Bidens pilosa have inhibition effects on the growth and development of gametophyte of Pteris multifida.