Root Ecology Of Invasive And Native Populations Of Chinese Tallow(Triadica Sebifera)

Studies on biological invasion mechanisms are important in invasion biology.In this study,the root morphology and root defense traits in the invasive plant Triadica sebifera were examined,to identify the differences in root morphological characteristics,physiological enzyme activity,and antibacterial activity of root systems between invasive and native populations.The root morphological parameters were observed using the root box method.The root defense ability was investigated through the pot experiment.A total of 10 populations,including 5 native populations and 5 invasive species,were selected for root morphology parameters measure,with 6 replicates for each population.20 populations,including 10 native populations and 10 invasive populations,were selected for root defense research,with 5 replicates in every population.The experimental results are as follows:(1)The comparative analysis results of the root morphological characteristics of the invasive and native populations showed that the root horizontal range of the invasive population was significantly lower than that of the native population.After grading of root diameters,the comparative analysis of the root parameters showed that the total length and total surface area of fine roots(1.5-2.0mm)of invasive populations were significantly higher than those of the native population.The other morphological indicators,such as the root vertical depth of the plant,the below-ground biomass of the plant,and the above-ground biomass of the plant,showed larger than the native population,but did not showed significant differences.(2)The analysis of the correlation between root morphology and above-and below-ground biomass showed that there are some differences in the correlation between the invasive and native populations: the total root length of the invasive population showed significant positive correlation with the above-ground biomass and below-ground biomass.At the same time,the total surface area of roots also showed significant positive correlation with above-ground biomass.However,there were no similar results in the native populations.(3)The results of three major antioxidant enzyme activity show that the SOD enzyme activity,POD enzyme activity,and root activity(TTC enzyme activity)of the invasive population were higher than the origin,but there were no significant differences.(4)Both the invasive population and native population had similar antibacterial activity against E.coli,and there was no significant difference between the native and invasive populations.They did not perform any antibacterial activity against Staphylococcus aureus.In conclusion,the results of this study show that root morphology changes may have a positive effect on the growth of the above-ground parts of invasive plants.The root exudates of Triadica sebifera have certain advantages in antibacterial physiology.This lays the foundation for further explaining the role of root changes in the invasion process of Triadica sebifera.