生态环境学报Issue(1)：7-15,9.
入侵藤本薇甘菊的耐盐能力
Salt tolerance of the invasive vine Mikania micrantha Kunth
摘要
Abstract
Mikania micrantha Kunth is a noxious invasive species in tropical and subtropical regions. This weed has been found to grow on the coast of the Pearl River Delta and off-coast islands in China. In the present study, we assessed the salt tolerance of M. micrantha seeds, roots, and stems separately. Seed germination and seedling growth in different concentrations of NaCl were tested for three M. micrantha populations and six common species (Eupatorium catarium, Ageratum conyzoides, Crassocephalum crepidioides, Bidens pilosa, Pterocypsela indica, and Ipomoea triloba) in the Pearl River Delta. Seed germination of M. micrantha, E. catarium, A. conyzoides, and B. pilosa were tested after 3, 6, and 12 days of submergence in different concentrations of NaCl to determine whether seeds can be transferred by seawater. Responses of submerged cultured M. micrantha root and stem in different concentrations of NaCl were also recorded to determine whether the weed can disperse by vegetative propagation in coastal saline soils. Experiments produced the following results. 1) In general, the seed germination rates of M. micrantha did not differ significantly from those of the controls at ≤0.6% salinity, and the highest threshold value of 1.5% was greater than those for all control species. Radicle and seedling height growth rates of M. micrantha were less suppressed than those of control plants under the same salinity stress. 2) In comparison with controls, no significant decline in germination rate was observed in treated (submerged in up to 3.0%NaCl for up to 12 days) M. micrantha, A. conyzoides, or E. catarium, whereas submergence in 3.0%NaCl for 12 days caused a significant decline in B. pilosa. However, seedlings of all four tested species grew well. 3) All tested M. micrantha plants survived 0.5%salinity stress to root systems, with a decline in the average seedling height growth rate to 53.3%those of controls;95%of tested plants survived up to 1.0%salinity stress to root systems for at least 25 days, with a decline in the average seedling height growth rate to 18.9%;no M. micrantha plant survived 1.5%salinity stress to the root system. 4) All leaves of M. micrantha survived stem submergence in water, with sprouting observed in all submerged nodes, whereas all submerged leaves died when stems were exposed to ≥1.0%salinity stress. Mortality rates of the tested stems at day 21 were 42.9%, 40.9%, and 86.4%for 1.0%, 2.0%, and 3.0% salinity stress, respectively. We conclude that M. micrantha can disperse in coastal saline soils by seed and vegetative propagation. More attention should be paid to the potential threat of M. micrantha populations near coastal halophytic vegetation.关键词
薇甘菊/入侵植物/NaCl胁迫/种子萌发/耐盐性Key words
Mikania micrantha Kunth/invasive plant/NaCl stress/seed germination/salt tolerance分类
农业科技引用本文复制引用
胡亮,李鸣光,韦萍萍..入侵藤本薇甘菊的耐盐能力[J].生态环境学报,2014,(1):7-15,9.基金项目
国家自然科学基金项目 （）
