摘要：Exotic invasion is considered as the second factor influencing biodiversity after habitat lose. Alligator weed(Alternanthera philoxeroides Griseb.), a perennial herb native to the South America, has established itselfon almost all the surface of the earth except Africa. In China, alligator weed has invaded most temperateregions where the environmental conditions, particularly temperature, are obviously different from its origin.How can alligator weed survive through cold winters is a critical issue for its establishment in these areas. Inthis research, we investigated the seasonal change of soluble sugars content (SSC), which presentedimportant physiological reaction to cold acclimation, in different parts including buds, nodes, and internodesof alligator weed from aquatic and terrestrial habitats. Results showed that accumulation of soluble sugarswas regularly correlated to temperature change in environment, i.e., the highest SSC in the coldest season,and the lowest in summer. Among different parts such as nodes, buds and internodes in individuals fromterrestrial and aquatic habitats, accumulation of SSC presented similar results. The accumulation of SSCand its seasonal dynamics may be a physiological acclimation to low temperature so that alligator weedcould establish in these regions and survive through cold winters ecologically.
