土壤灭菌处理对入侵植物南美蟛蜞菊及其伴生种生长的影响

该研究以温室盆栽法对南美蟛蜞菊重度入侵土壤进行高温高压湿热灭菌、添加杀真菌剂灭菌和添加杀细菌剂灭菌的处理后,将三种植株定植96 d后测定各生理指标参数,研究重度入侵土壤中各微生物类群对南美蟛蜞菊及其伴生种金腰箭和狗肝菜生长的影响。结果表明:在杀真菌、杀细菌以及高温高压湿热灭菌和未处理的南美蟛蜞菊重度入侵土壤中,三种植物生长情况均存在较大差异。在高温高压湿热灭菌土壤中南美蟛蜞菊的生长受到显著抑制,与未处理土壤中的生长情况相比,株高降低了17.59%,叶片数降低了38.10%,生物量降低了56.00%,电子传递速率变化不明显。在杀真菌土壤和杀细菌土壤中金腰箭的生长也受到显著抑制,与未处理土壤中的生长情况相比较,杀真菌土壤中的金腰箭株高降低最多(为42.28%),叶片数降低了38.89%,生物量降低了16.99%,电子传递速率变化不明显;在杀细菌土壤中金腰箭株高降低了36.64%,叶片数降低最多(为38.89%),生物量降低了33.67%,电子传递速率升高了11.11%。由此可见,不含微生物的土壤对南美蟛蜞菊生长有较强的抑制作用,不含真菌和细菌的土壤对金腰箭的生长有明显抑制作用。南美蟛蜞菊重度入侵土壤不仅适合南美蟛蜞菊的生长,也适合金腰箭的生长,对狗肝菜影响不大。

Effects of soil sterilization on growth of invasive plant Wedelia trilobata and its associated species

Invasive plant Wedelia trilobata and its associated species of Synedrella nodiflora and Dicliptera chinensis were utilized by potted plant method in greenhouse to compare the effects of soil microorganism on the growth of three plants. The plant height, biomass, leaf number, photosynthetic electron transport rate of three plants were determined after cultivated in the Wedelia trilobata invaded soil for 96 d. The soil sterilized by high temperature and high pressure, or adding fungicide and bactericide sterilization. The experiment indicated that the growth of the three plants described above was different in disparate soil. The strongest growth inhibition was W. trilobata in sterilization soil. Compared with the growth of plants in untreated soil, the plant height was decreased by 17.59%, the number of leaves decreased by 38.10%, biomass was reduced by 56.00%. The growth inhibition of Synedrella nodiflora was the greatest in anti-fungal soil. Compared with the plant in untreated soil, the height, the number of leaves, biomass, the electron transfer rate of S. nodiflora was decreased by 42.28%, 38.89%, 16.99%, 7.41%. The growth inhibition of S. nodiflora was also the greatest in anti-bacteria soil, compared with the growth in untreated soil, the plant height was decreased by 36.64%, the number of leaves was decreased by 38.89%, biomass was reduced by 33.67%, the electron transport rate was increased by 11.11%. The soil without microbes had strong inhibitory effect on the growth of Wedelia trilobata. The growth of fungi and bacteria in the soil of Synedrella nodiflora had obvious inhibitory effects. The soil invaded by Wedelia trilobata was not only suitable for W. trilobata''s growth, but also for its associated species of Synedrella nodiflora''s growth. However, it had little effect on the Dicliptera chinensis. The invasion of alien plants into the new habitat, under appropriate conditions, spread, resulting in the loss of local biodiversity. In the whole process, soil microbes played a bridge role. The effects of different soil microbial communities on plant growth and feedback function, explained the ecological effects of soil microbes in the invasion process, and revealed the significance of the mechanism for the invasion. Explained study aimed at different groups of soil microbes including the effects on the growth of invasive plant Wedelia trilobata and associated species Synedrella nodiflora and Dicliptera chinensis. The index of the three kinds of plants were exploratory experiment, in order to find the influence of different kinds of microbes associated with the growth of invasive plants. And further analysis on vegetation and soil microbial community mutual relations, explored the mechanism of exotic plant invasion from the below ground plants on the ecological point of view. This study provides effecient ways for the effective prevention and control of alien invasive plants, and maintaining the stability of the ecosystem.