Adventitious roots support population expansion of the invasive plant Mikania micrantha Kunth

Abstract

Mikania micrantha Kunth is a serious invasive alien plant characterized by the formation of an adventitious root system in its prostrate growth form. Unlike the initial roots from seed germination, adventitious roots gradually appear above the stem and branch nodes. Little is known about adventitious roots play on plant growth and population expansion of M. micrantha. We hypothesized that adventitious roots provide an advantage for plant growth and nutrient availability. To test this hypothesis, plant growth, physiology, and nutrition characteristics of M. micrantha were measured under four soil surface conditions allowing various plant parts to touch the soil to stimulate variable adventitious root formation. The results showed that the biomass, stem length, branch number, and adventitious root biomass of M. micrantha were significantly increased (P < 0.05) with increasing nodes bearing adventitious roots. As the number of nodes with adventitious roots increased, the net photosynthetic rate, antioxidant enzyme activities like superoxide dismutase, catalase, peroxidase, and malondialdehyde, chlorophyll content, and plant nutrient contents (N, P, and K) of M. micrantha were increased (P < 0.05), with higher values in main stem leaves than in those of branch leaves. The concentrations of soil organic matter, total N, total P, total K, available N, available P, and available K were greater (P < 0.05) in initial soil (CK) than in treatment soil (with M. micrantha) and were significantly reduced by adventitious roots. Our study was the first to show that plant growth, physiology and nutrition status of M. micrantha were strongly promoted by adventitious roots in the prostrate growth form.

Sweet potato (Ipomoea batatas) and hyacinth bean (Lablab purpureus) in combination provide greater suppression of mile-a-minute (Mikania micrantha) than either crop alone

“… Zhang and Wen (2008) demonstrated that infestation of mile-a-minute by the insect Bemisia tabaci resulted in significantly decreased SOD and CAT activities, and consequently harmful active oxygen species (AOS) were more difficult to eliminate ( Zhang and Wen, 2008 ). Antioxidant enzyme activities (SOD, CAT, POD, and MDA) were shown to increase for mile-a-minute when plants bore more nodes with adventitious roots ( Shen et al., 2021 ). Competitive relationships have been shown to influence SOD, POD and CAT activities, such in the case of competition between sweet potato and the invasive plant Ageratina adenophora ( Shen et al., 2019a ).…”

“…Both sweet potato and mile-a-minute produce large numbers of adventitious roots from the main stem and branch nodes as stimulated by contact with the soil surface ( Shen et al., 2015 ). The adventitious roots of mile-a-minute may positively contribute to its plant nutrient contents and soil nutrient absorption ability ( Shen et al., 2021 ). Sweet potato growth was particularly sensitive to fertilization level whereas under various fertility levels the density of competitors was more important than fertilization for mile-a-minute ( Shen et al., 2020 ).…”

“…Mile-a-minute may produce large numbers of adventitious roots ( Shen et al., 2015 ). These adventitious roots positively contribute to the growth of mile-a-minute, increasing plant nutrient content and soil nutrient absorption, chlorophyll content, and activities of antioxidant enzymes ( Shen et al., 2021 ). Thus, when seeking plants to suppress the growth of mile-a-minute, the best candidates may be species that have similar niches and growth patterns to mile-a-minute.…”

Potential distribution and ecological impacts of Acmella radicans (Jacquin) R.K. Jansen (a new Yunnan invasive species record) in China

“…Invasive alien plants can reduce species richness, species diversity indices, evenness index, and native community structure and function[9,49,50]. The tendency of invasive plants to rapidly gain a competitive advantage over neighboring plants is attributed to their rapid growth, reproductive propagation ability, adaptation to a broad range of habitats, and strong allelopathic profiles[51][52][53][54]. By the second year of our five-year field survey, A. radicans had become the dominant and most densely populated species within the plant communities we monitored.…”