入侵杂草薇甘菊叶不同发育期微形态特征研究

Study on Micromorphological Characteristics at Different Developmental Stages of Invasive Weeds Mikania micrantha Leaf

[目的]揭示薇甘菊叶不同发育时期微形态学特征,为深入了解该入侵物种的生理特性及生态适应性提供重要参考。[方法]利用临时装片法,在光学显微镜下观测叶表皮细胞、气孔器及表皮毛的形态性状。[结果]叶长2.90~6.05 cm时,上表皮细胞面积和长宽随着叶生长呈现稳步上升趋势,叶长6.50~14.00 cm时,上表皮细胞面积和长宽变化相对较小,总体上表现为缓速增长;下表皮细胞随叶生长变化较小,但长宽比均值与上表皮差距很小;气孔器主要发生在下表皮,叶长对气孔器面积比的影响较小,气孔器的长宽及长宽比没有随发育期的变化出现明显波动;展叶期上表皮毛个数大于下表皮,随着叶的发育成熟,迅速减少。[结论]薇甘菊叶的不同发育期表皮微形态特征受环境因素的影响,反映叶片发育与其功能相适应。

[Objective]To reveal the micromorphological characteristics at different developmental stage of Mikania micrantha leaf,which provides an important reference for further understanding of the physiological characteristics and ecological adaptation of this invasive species.[Method]The morphological features of epidermal cells,stomata and epidermal hair were observed under light microscopy using temporary slide method.[Result]The area and length of adaxial epidermal cell increased steadily during leaf length 2.90 cm to 6.05 cm,while between 6.50 cm to 14.00 cm,the epidermal cell area changed relatively little.The abaxial epidermal cells change less with leaf growth,and the difference of the length/width between the adaxial and abaxial epidermis was very small.The stomata mainly occur in the adaxial epidermis,and the leaf length has less effect on the area ratio of stomata.The length,width and length/width of stomata does not fluctuate significantly in different development period.The number of epidermal hairs in the adaxial epidermis is greater than that of the adaxial epidermis,and decreases rapidly as the leaves mature.[Conclusion]Environmental factors influence the leaf micromorphological characteristics of Mikania micrantha,which reflects that the leaf development is adapted to its function.