The Effects Of Drought Stress On The Morphology And Physiological Response Of Five Flower Borders

With the development of urbanization,urban afforestation has a higher and higher demand for plant biodiversity and landscape diversity.Flower border plants are important plant materials in modern urban afforestation,and their functions are increasingly important.There are many flower border plants in Jiangxi Province.It is of great practical significance and production value to study the drought resistance of flower border plants,the selection of flower plants and the application of greening and landscaping in urban construction.Selectionofchamaemelumnobile?Euryopspectinatus'Viridis'?,daylily?Hemerocallis aurantiaca Baker?,orchid notoginseng?Liriope cymbidiomorpha?ined??,tulbaghia violacea?Tulbaghia violacea?and chasmanthium latifolium?Chasmanthium latifolium?in Jiangxi Academy of Forestry.Five species of flower border plants were used as research objects for drought resistance.Drought days were set for 5 days,10 days,15days,20 days,25 days,and CK.Agronomic traits and photosynthetic characteristics were measured.Variance analysis and Microsoft Excel 2016 were used for mapping.Five kinds of flower border plants were assessed using the membership function.The drought resistance was evaluated to determine the difference in drought resistance of the five flower border plants.Through the study,the following preliminary conclusions are obtained:?1?With the increase of drought days,the total number of leaves,green leaves,leaf area and chlorophyll were decreased.?2?The longer the drought time,the lower the soil moisture content.The largest water consumption is chasmanthium latifolium,followed by chamaemelum nobile.?3?The descending order of total biomass was chamaemelum nobile>chasmanthium latifolium>daylily>tulbaghia violacea>orchid notoginseng;?4?The net photosynthetic rate began to decline after 15 days of drought,and the net photosynthetic rate was the strongest at 14:00,and there was no lunch break.?5?At 12:00,the stomatal conductance and transpiration rate of chamaemelum nobile and daylily were the highest,the transpiration rate and the CO₂ concentration of orchids notoginseng was was the lowest.?6?The water use efficiency of orchid notoginseng was the highest,and the water use efficiency of chamaemelum nobile was the lowest.?7?The CK of chamaemelum nobile,tulbaghia violacea and chasmanthium latifolium has the highest temperature,reaching 45.9°C and 45.3°C.When the drought time increases,the leaf temperature drops to 38.0°C,and the drought-treated leaf temperature is less than CK about 4.0-5.0°C.In summary,different flower border plants showed obvious responses to drought stress in terms of growth morphology and physiological changes.Comprehensive agronomic traits and photosynthetic characteristics were used to evaluate the drought resistance of five flower border plants using the membership function assessment method.The drought-resistance of orchid notoginseng was the strongest,followed by tulbaghia violacea and daylily.The drought resistance of chamaemelum nobile and chasmanthium latifolium was the worst.