Study Of Water Adaptability Physiology Of Four Perennial Flowers Of Gaillardia Aristata

Since the 20th century,frequent climate changes have caused many natural disasters.Water is an essential material for plants,but a certain amount of water above or below will cause changes in plant morphology and physiology.Therefore,the research of plant resistance has become a key subject for experts and scholars.In the construction of garden landscape,it is particularly important to choose suitable plants to green and beautify the city.Perennial flowers have high ornamental and ecological adaptability,low maintenance costs,extensive management,and are favored by more and more gardeners.In this experiment,four species of perennial flowers in the Compositae family: Gaillardia aristata,Chrysanthemum morifolium,Dendranthema indicum,Achillea millefolium are tested for drought stress and flooding stress respectively.The drought stress was carried out by the natural drought stress method.The morphological characteristics of plants at various time points(CK,W4,W8,W12,W16,R2,R4)were observed,and the physiological and biochemical indicators(Pro,SP,SS,MDA,Chl)were measured at the same time;The water stress was carried out by double-pot method,and the morphological characteristics of plants at each time point(CK,W4,W8,W12,W16,R2,R4)were observed respectively,and the physiological and biochemical indexes(Pro,SP,SS,MDA,Chl)were measured.The fuzzy membership function method was used to analyze and compare the drought resistance and flood resistance of four species of perennial flowers of Compositae,At the same time,the principal component analysis method is used to compare the strength of each index reflecting drought resistance and flood resistance.The research conclusions are as follows:(1)Drought stress: As the drought stress gradually intensified,the four types of flowers showed varying degrees of water loss,curling,chlorosis,drooping,and wilting.Among them,the Gaillardia aristata was due to its large leaf area.The morphological changes under stress are more significant.After rewatering,the growth can be restored,but the old leaves need to be cleaned in time to improve the ornamental value.The content of Pro and SP of the four flowers showed a trend of increasing first and then decreasing.The overall trend of SS and MDA content was increasing,but the trend of change was different,and the content of Chl was continuously decreasing.After rehydration,the contents of Pro and SP in Perennial Tianrenju and Xiaju were significantly higher than the control,and the contents of SS,MDA,and Chl were significantly lower than the control.In addition to the MDA content of Dendranthema indicum and Achillea millefolium,other physiological indicators were significantly lower than those of the control.The MDA content of Dendranthema indicum was significantly higher than that of the control,but Achillea millefolium had no significant difference compared with the control.(2)Flooding stress: With the prolonging of the flooding stress,the leaves and stems of the 4 kinds of flowers showed different degrees of discoloration,drooping,and leaf margins withered.Among them,the Gaillardia aristata changed most significantly.The color change cannot be restored in a short time,and the viewing value is not good.The relative water content of the 4 kinds of flowers gradually decreased,but the change was relatively small.After drainage,the Gaillardia aristata and Dendranthema indicum were significantly lower than the control,and the Chrysanthemum morifolium returned to the control level,but the difference was not significant.The content of Pro and MDA in the four flowers showed a gradual increase trend.The content of SP increased first and then decreased.The SP content of ratoon chrysanthemum and Xia chrysanthemum increased slightly in the later period of stress,the content of SS increased first and then decreased,and the content of Chl decreased.-Rising-falling trend.After the waterlogging was drained,the physiological state of the four flowers recovered,but the damage to the plant morphology could not be recovered.(3)Membership function and principal component analysis: Use the membership function analysis method to rank the resistance of the four species of perennial root flowers of Compositae from large to small,among which the drought resistance is: Achillea millefolium >Chrysanthemum morifolium > Dendranthema indicum > Gaillardia aristata;Waterlogging resistance: Chrysanthemum morifolium > Achillea millefolium >Dendranthema indicum > Perennial root Celestial chrysanthemum.According to the comprehensive analysis of the ranking situation,the water adaptability of the four species of perennial root flowers in the Compositae family is as follows:Chrysanthemum morifolium and Achillea millefolium have stronger water adaptability,Achillea millefolium have better drought resistance ability than Chrysanthemum morifolium.According to the principal component analysis method,the physiological indexes reflecting the resistance of the 4 perennial flowers,from high to low,are: drought resistance: Pro,MDA,SS,SP,Chl,RWC;waterlogging resistance: Pro,MDA,SS,Chl,SP,RWC.According to the ranking,it can be known that Pro,MDA and SS play an important role in drought and flooding stress.