Abstract
This study investigated the effects of the mud-sinking (MS) method, agar gel-sinking (AS) method and agar gel-sinking with artificial aquatic mat (ASA) method on the growth, physiological characteristics, water purification capacity, and associated microbial community of the different organs of Vallisneria natans (V. natans). Results showed that the growth of agar-based growth (group AS and ASA) were more effective than the mud-wrapped method (group MS), exhibiting longer length, higher fresh weight and biomass of agar-based V. natans with the artificial aquatic mat (group ASA) being higher than those of other groups. MS caused a stress response in the oxidative system, which then inhibited photosynthesis. Results of water quality measurements showed that the three planting methods positively affected water purification without significant differences (p > 0.05). Besides, there was no significant difference (p > 0.05) between the microbial communities in terms of the roots and those found in rhizosphere soils in the MS group with high throughput sequencing. Meanwhile, the addition of agar in the AS and ASA groups increased the diversity of rhizosphere soil microbial communities and reduced the diversity of root microbial communities. Microbial community compositions in the rhizosphere soil and root differed significantly (p < 0.05). High throughput sequencing and scanning electron microscopy (SEM) also revealed that the biofilm on the surfaces were different, with Proteobacteria and Cyanophyta consistently dominating. This study provides new insights on the more effective revegetation methods of V. natans, researched the environmental impact of the addition of agar, and provides some theoretical support for the revegetation of submerged macrophytes under ecological restoration.
Highlights
For eutrophic lakes, pollution from external inputs affected the normal succession of plant communities, severely affecting the vegetation and causing degradation of the lake’s ecosystem.In most cases, gradually transformation is observed from grass-dominated to grass-algae dominated communities, further shifting to algae-dominated environments [1,2], primarily due to eutrophication.Nutrient accumulation in the lake stimulates phytoplankton blooms, the biomass of which significantly reduces light penetration, decreasing dissolved oxygen concentration, which limit the growth of the submerged plants
This study demonstrates that the damage to the anti-oxidation defense system caused by MS was greater than that of agar gel-sinking (AS) or ASA on V. natans, further confirming the superiority of agar cover on the growth ofcontent
Results showed that compared with the mud-wrapped method, the agar-based method effectively promoted plant that compared with the mud-wrapped method, the agar-based method effectively promoted plant growth and photosynthesis, and reduced physical damage to plants, with the antioxidant system growth and photosynthesis, and reduced physical damage to plants, with the antioxidant system stress response much lighter
Summary
Pollution from external inputs affected the normal succession of plant communities, severely affecting the vegetation and causing degradation of the lake’s ecosystem. Submerged plants have been gaining interest since they grow fast and can absorb large amounts of nutrients from the sediment and overlying water, causing the dissolved oxygen to increase and the water quality to improve Their secretion of allelochemicals can effectively inhibit the growth of algae. It is extremely important to develop submerged plant revegetation method with a high survival rate suitable for poor water quality environments. Past studies on the restoration of submerged plants mainly compared the effects of common methods on plant biomass and water quality [20,23,24], but not the microbial communities. Vallisneria natans (V. natans) is a common perennial submerged plant with wide adaptability and high tolerance to pollution It is regularly used as a pioneer species in vegetation restoration efforts in eutrophic waters [25]. The impact of different planting methods of V. natans on purification of water bodies and bacterial communities on the root system, rhizosphere soil, and plant leaf surfaces were evaluated
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
