田野菟丝子寄生对薇甘菊气孔行为的影响

田野菟丝子寄生已成为当前控制薇甘菊入侵蔓延的最佳生物防治手段之一。应用扫描电子显微镜技术,观察并统计分析了田野菟丝子寄生对薇甘菊叶片气孔形态参数的影响,为了解寄生对薇甘菊生理特征的影响提供一定的形态学依据。结果表明,田野菟丝子寄生对薇甘菊叶片的气孔长宽比和气孔面积产生显著影响:对照薇甘菊叶片的气孔长宽比和气孔面积表现为双峰日变化动态;而被寄生的薇甘菊的叶片气孔长宽比和气孔面积则表现为单峰日变化规律。对照薇甘菊气孔的长宽比分别在12:00和10:00,气孔面积分别在10:00和14:00达到日变化中的最大值与最小值;在15:00到16:00气孔长宽比和气孔面积再一次达到一个峰值,使气孔长宽比和气孔面积的日波动形成一个双峰曲线。被寄生的薇甘菊的叶片气孔长宽比和气孔面积则表现出单峰曲线,峰值分别出现在12:00和14:00。田野菟丝子寄生对薇甘菊的气孔密度没有产生显著影响。

Influence of the obligate parasite Cuscuta campestris on the leaf stomatal behavior of its host Mikania micrantha

It has been recognized that the use of the obligate parasite Cuscuta campestris is one of the most effective means of biologically controlling the invasive weed Mikania micrantha. In order to provide some certain morphological evidences underlying the effects of C.campestris on the physiology of M.micrantha,we studied the influence of C.campestris infection on the morphological parameters of leaf stomata of M.micrantha under a scanning electron microscope. The results indicated that infection with C.campestris had significant effects on diurnal stomatal behavior of M.micrantha leaves. Both stomatal length to width ratio and stomatal area of the leaves in the control plants showed a bimodal diurnal pattern,while those for the infected exhibited a mono-peak pattern. The diurnal peak values of stomata length to width ratio and stomatal area of the control leaves appeared at 12 h and 10 h,while the minimum values appeared at 10 h and 14 h,respectively. From 15 h to 16 h,the ratio and stomatal area reached another less peak value. For the leaves of the infected M.micrantha,the mono-peak values of the stomata length to width ratio and stomatal area appeared at 12 h and 14 h,respectively. The results also indicated that infection with C.campestris had no significant effects on the stomatal density of M.micrantha leaves.