Effects of water temperature on growth of invasive Myriophyllum aquaticum species

This study sought to investigate the invasive mechanism of Myriophyllum aquaticum by subjecting it to simulation experiments in varying water temperatures ranging from 0 °C to 30 °C. The results showed that water temperature considerably affected both the growth and reproduction of M. aquaticum. The optimal temperature range for the growth of M. aquaticum was 25‒30 °C. Although the growth of M. aquaticum was inhibited at temperatures between 0‒5 °C, this did not result in mortality. The stem nodes, branches, and diameter reached maximum values over a temperature range of 20‒25 °C. High-temperature stress at 30 °C led to a gradual decrease or disappearance of branches. Compared to the 0 °C, 5 °C, and 30 °C treatment groups, a temperature of 20 °C led to biomass accumulation and significantly higher values. M. aquaticum’s physiological activities were affected by temperature. Except for 10 °C and 15 °C, the catalase activity varied among different water temperatures. M. aquaticum catalase activity was maximal at 5 °C and minimal at 25 °C. Conversely, the synthesis of photosynthetic pigments was highest at 10 °C and 15 °C. The plant’s optimal temperature for growth was between 20 °C and 25 °C. When the temperature was <10 °C, M. aquaticum adapted to the water temperature’s potential damage. This plant has a notable ability to tolerate various temperatures.