Biological Effects Of Soil Mercury On Plant Growth And Microbial Community

In recent years,heavy metal pollution in soil has gradually become a hot topic of research,and soil mercury pollution has received more and more attention from various research departments.As a global regional pollutant,mercury is easy to migrate and difficult to control,and it is easy to produce highly toxic pollutants such as methylmercury under the action of microbial plants.In order to clarify the phytotoxic effects of soil mercury pollution,a pot experiment was carried out using simulated mercury-contaminated soil to select wheat.The spinach and pakchoi were evaluated for crops and the effects of different levels of mercury contaminated soil on wheat and water spinach were studied.The results showed that low concentration of mercury pollution slightly promoted the growth of wheat.Mercury concentration above 34 mg·kg-1 significantly inhibited the growth of wheat and water spinach,causing physiological phenomena such as small leaf area,chlorosis and yellowing and even withering.With the increase of mercury concentration,the content of malondialdehyde(MDA)increased;with the increase of mercury concentration,the activity of superoxide dismutase(SOD)increased,and SOD was treated with mercury concentration of 124 mg·kg-1.The activity is maximized.Pakchoi is a mercury-sensitive plant,and a relatively low-level soil mercury toxicity test has been carried out on pakchoi.The results show that when the amount of mercury in the soil is>2.59 mg·kg-1,the pakchoi produces a more obvious toxicity.Pakchoi can be used as a toxicity indicator to assess the degree of mercury toxicity in the soil.Through the statistical analysis of the experimental results of pakchoi and spinach,it was found that the mercury concentration in the soil caused by mercury in the cabbage and spinach was less than 50%,and the concentration of mercury in the soil was 5.64 mg·kg1 and 32.79 mg·kg-1.In the early stage of germination,the degree of mercury stress in the soil was less than that of cabbage>water spinach>wheat.By fitting the growth index inhibition data of wheat,water spinach and pakchoi under mercury stress,it is concluded that the concentration of mercury pollution in the soil on the biomass of wheat,water spinach and pakchoi in this experimental research system is 72.24 mg·kg-1 and 183.83 mg·kg-1 and 10.69 mg·kg-1.At the same time,the microbial community in the soil was analyzed and analyzed.The microbial respiration of the soil before and after planting was determined.At the same time,the microbial flora in the soil was analyzed by high-throughput sequencing.The experiment also showed that the soil mercury pollution on the.plants The microbial diversity in the rhizosphere soil is inhibited,and it has a significant impact on the abundance distribution of the microbial community.It may change the dominant species of the microbial community in the soil,affecting the conventional indicators of the soil,and thus affecting the crops in the soil.