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

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