Comparative Study On The Antibacterial And Bactericidal Abilities Of Six Garden Plants

Cinnamomum japonicum,Citrus maxima,Osmanthus fragrans,Magnolia grandiflora,Michelia figo,and Cinnamomum camphora,with high ornamental value and ecological functions,are highly used ornamental aromatic plants in Changsha,with strong resistance,strong adaptability and other advantages.In order to explore their bactericidal ability for better application in garden green space,this paper took six plants and their communities as research objects,investigated and analyzed the species composition,community structure and microclimate environment characteristics of the communities.The bactericidal and bactericidal ability and dynamic changes of plant leaves in vitro,individual and plant community at different growth stages,different species of plants,daily dynamic changes and seasonal changes were measured,and the ecological benefits of individual plants and plant communities were evaluated.On this basis,suggestions for optimizing the allocation of artificial plant communities in urban green space were put forward to provide guidance for the application of six kinds of plants in gardens.The following conclusions are drawn:(1)The bacterial concentration in the detached leaves of six plants was highest in spring,followed by autumn and summer,and lowest in winter.The seasonal variation pattern of antibacterial rate is currently higher in summer and autumn,followed by spring,and the lowest in winter,with an average value of 14.20%.Cinnamomum camphor leaves had the best bacteriostatic and bacterioidal effect(33.91%),followed by cinnamomum leaves,pomelo leaves,osmanthus leaves and Magnolia lotus leaves.The bacteriostatic and bacteriostatic and bacterioidal effect of Michelia sinensis leaves was the weakest(23.49%).(2)The order of the annual average temperature difference of six plant individuals is asfollows:Cinnamomum japonicum>Cinnamomum camphora>Osmanthus fragrans>Citrus maxima>Michelia figo>Magnolia grandiflora.The effect of cooling and humidifying and the concentration of air bacteria showed an "inverted U-shaped" diurnal trend.The overall order of the concentration of air bacteria was as follows:Michelia,Magnolia,Osmanthus,Pomelo,Geranium,Cinnamomum camphora;The average bacteriostatic rate of individual plant at each time point was ranked as follows:12:00>14:00>10:00>16:00>8:00>18:00.The concentration of bacteria in the air shows spring>autumn>summer>winter.The seasonal variation of the individual antibacterial effect was higher in summer and autumn,followed by in spring,and the lowest in winter,with an average value of 5.08%.The comprehensive analysis shows that the individual bacteriostatic rate of six plants is as follows:Cinnamomum camphora>Cinnamomum japonicum>Citrus maxima>Osmanthus fragrans>Magnolia grandiflora>Michelia figo.(3)On the whole,the bacterial concentration of the six plant flowers showed a"U-shaped" diurnal variation trend,and the bacteriostatic and bactericidal efficiency of the six plant flowers was low in the morning and high in the middle,showing a"single-peak" diurnal variation trend.The order of the average bacteriostatic rate at different time points was:14:00>12:00>16:00>14:00>8:00>18:00.The concentration of air bacteria was the highest in the late flowering stage,followed by the early flowering stage,and the lowest in the full flowering stage;The bacteriostatic and bactericidal rates were the highest at the flowering stage,followed by the first flowering stage,and the lowest at the last flowering stage,with an average value of 24.02%.According to the average bacteriostatic rate of different plants at flowering stage,the bacteriostatic and bacterioidal effect of Cinnamomum camphora was the best(36.12%),followed by cinnamomum japonica,Pomelo,Osmanthus and Magnolia lotus,and the bacteriostatic and bacterioidal effect of Michelia was the weakest(24.33%).(4)The plant community showed the best bacteriostatic and bactericidal effect from 12:00 to 14:00.The average bacteriostatic rate at different time points in a day was in the order of 12:00>14:00>10:00>16:00>8:00>18:00;The seasonal variation characteristics of the bacteriostatic effect of plant community were summer>autumn>spring>winter.The order of antibacterial and bactericidal effects of plant community is:QL01>QL02>QL03.(5)The seasonal variation trend of cooling effect of plant community is summer>spring>autumn>winter;The humidifying effect of plant community is the best at 12:00,and the seasonal variation trend of humidifying effect is better in summer and autumn,followed by spring,and the worst in winter;The CO2 concentration in the plant community showed a daily variation trend of "first fallinggentle-then rising",and the seasonal variation trend of CO2 concentration was winter>spring>autumn>summer;The seasonal variation trend of negative ion concentration of plant community is:autumn>summer>spring>winter.(6)According to the analysis of comprehensive ecological benefits,it is concluded that the comprehensive ecological benefits of plant community are the best of QL01,followed by QL02,and the worst of QL03.Based on the ecological benefits,suggestions for optimizing the allocation of plant community.The QL01 with the best comprehensive ecological benefits(Cinnamomum japonicum+Cinnamomum camphora+Choerospondias axillaris+Ligustrum lucidum+Osmanthus fragrans+Michelia chapensis+Acer fabri+Aphananthe aspera+Cycas revoluta-Ilex cornuta+Euonymus japonicus+Loropetalumchinens+Fatsia japonica-Zoysia japonica+Artemisia argyi +Ophiopogon bodinieri+Oxalis corymbosa+Iris tectorum)can be popularized and applied in urban landscaping construction to effectively retain and absorb air particles and improve air quality;At the same time,it can also be extended to the landscape greening of corresponding residential areas,schools,sanatoriums and hospitals to improve the environmental quality and achieve better ecological benefits and landscape appreciation.