3种入侵植物叶片挥发物对旱稻幼苗根的影响

入侵植物通过化感作用对入侵地的生态系统构成了严重的威胁,影响了入侵域农作物的生产。采用石蜡切片技术,利用光学显微镜进行观察,研究了不同质量浓度的黄顶菊、三叶鬼针草、胜红蓟3种入侵植物的叶片挥发物对旱稻幼苗初生根的结构以及根系发育的影响,结果表明:低质量浓度(5g)的三叶鬼针草和胜红蓟叶片挥发物对根皮层起抑制作用,低质量浓度(5g)的三叶鬼针草挥发物对维管柱有促进作用,而黄顶菊挥发物对髓腔影响比较大,表现为低浓度抑制,高浓度促进;20g质量浓度的三种入侵植物叶片挥发物对旱稻幼苗初生根结构影响最大,均出现结构上的变异;对侧根的发育随浓度的增加而呈现明显的抑制作用,20g质量浓度时没有侧根的发生。表明入侵植物对受体植物根结构的影响随植物种类和挥发物浓度的不同而有不同的特点。

The influence of volatiles of three invasive plants on the roots of upland rice seedlings

The invasive plants not only posed a serious threat through allelopathy in the ecosystems of invasion but also had a serious influence on local crop production. Our objective was to study the influence of volatiles of Flaveria bidentis, Bidens pilosa and Ageratum conyzoides on the roots' development of upland rice seedlings and its primary structure. The structure of the rice roots were observed through the Paraffin sections technology and optical microscope observation technology. The results showed that the volatiles of the invasive plants had a stronger inhibitory influence on the occurrence of lateral roots of upland rice seedlings. There was no lateral roots development at high concentration (20g). The volatiles of the invasive plants had a certain impact on the primary structure of roots of upland rice seedlings. The volatiles of Bidens pilosa and Ageratum conyzoides(5g) had a inhibitory influence on the cortex of roots and the volatiles of Bidens pilosa (5g) had a stimulative influence on the vascular cylinder of roots. The volatiles of Flaveria bidentis had an inhibitory influence on the vascular cylinder of roots for the low concentration and a stimulative effect on the vascular cylinder for the high concentration. The primary structure of the roots made a variation and there was no lateral root at the high concentration(20g).The effect of the invasive plants on the structure of the root depended on the kinds of the plant and the concentration of the volatile.