期刊
ENVIRONMENTAL AND EXPERIMENTAL BOTANY
卷 48, 期 2, 页码 119-128出版社
PERGAMON-ELSEVIER SCIENCE LTD
DOI: 10.1016/S0098-8472(02)00018-7
关键词
invasive species; flood tolerance; aerenchyma; adventitious rooting; ethylene; wetlands; tall whitetop
Lepidium latifolium, perennial pepperweed, is an exotic crucifer that has spread explosively in recent years in wetlands and riparian areas of the western United States. Adaptive responses of L. latifolium to different durations of 0, 3, 7, 15, 30 and 50-day soil flooding treatment were investigated. Biomass allocation, adventitious rooting, aerenchyma development and ethylene production in plants were measured. Compared with controls maintained at - 20 kPa soil matric water potential, flooding stress reduced total biomass of L. latifolium. After 7 days of flooding, the total biomass and root/shoot ratio of flooded plants were significantly less than those of unflooded controls. The number of adventitious roots on the stem base increased with the duration of flooding. Root porosity was much higher in the flooded plants than in the unflooded controls after 3 days of treatment and rose to 43% after 50 days. Ethylene production in roots was higher in flooded plants than in the control throughout the 50-day duration of flooding and peaked at 7 days. The reduction in the root/shoot ratio, adventitious rooting, and aerenchyma development in flooded L. latifolium are important contributions to flood tolerance. L. latifolium resembled species adapted to standing water conditions in terms of having an initially high porosity, but it resembled species adapted to either saturated or occasionally flooded habitats in terms of the degree of increase in root porosity under flooded conditions. However, in growth of biomass, L. latifolium was more like plants that do not grow in mostly saturated conditions. Thus, L. latifolium appears to be a plant that exhibits plasticity to tolerate or survive saturated conditions, but not to grow well under these conditions. This may be an adaptation to arid or semiarid riparian habitats where spring flooding and summer drought are characteristic. (C) 2002 Elsevier Science B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据