The Research Of Water Stress On Four Kinds Of Plants Such As Sedum Yvesii,Etc.and Its Applications In Landscape

To study the waterlogging and drought tolerance ability, applications in landscape of Sedum yvesii, Sedum sarmentosum,Sedum aizoon and Sedum emarginatum.we studied the physiology characteristic and growth conditions of 4 plants under different moisture gradient of water through water stress and field experiment,the results were as follows:(1)Water stress experimental results showed that:with deepening of water stress and time gone on,the natural saturation deficit of 4 plants tended to increase, the range of the rise in order from high to low was Sedum yvesii, Sedum sarmentosum,Sedum aizoon. Sedum emarginatum. Relative water content and natural saturation deficit is negatively correlated. The plasma membrane relative permeability of 4 plants tended to increase too,the biggest change was Sedum aizoon. The chlorophyll relative content of 4 plants showed a tendency to reduce,the range of the decline was Sedum yvesii> Sedum aizoon> Sedum sarmentosum> Sedum emarginatum. On the index of chlorophyll fluorescence kinetics parameters:the Fv/Fm values of Sedum aizoon tended to increase, and the remaining 3 plants decreased; The Fv’/Fm’ and ETR values tended to decrease overall, the range of the reduce was Sedum yvesii> Sedum sarmentosum>Sedum emarginatum> Sedum aizoon,;the qP values of 4 plants presented first lowering then rising as a "V" shaped trend. On the index of external morphological characteristics:when under submergence stress, the growing external merits of the 4 plants order was Sedum aizoon, Sedum sarmentosum, Sedum emarginatum. Sedum yvesii; when under slight and moderate drought stress,Sedum sarmentosum and Sedum aizoon growed better than control group;when under heavily and extreme drought, the growing external merits of the 4 plants order was Sedum aizoon,Sedum emarginatum,Sedum sarmentosum, Sedum yvesii.(2) By making use of subordinate function analysis at the basis of the indexes above, results showed the order of waterlogging tolerance ability of the 4 Sedum plants is Sedum aizoon> Sedum sarmentosum>Sedum emarginatum>Sedum yvesii;the drought tolerance ability is Sedum aizoon>Sedum emarginatum>Sedum sarmentosum>Sedum yvesii.(3) The field tests showed that:when planted in the pool, Sedum aizoon in the form of container seedling can grow normally in first 30 days,the remaining 3 Sedum plants in the form of container seedling can stand 20 days flooded. When planted in low-lying land and shade environment,4 Sedum plants can growed normally.When planted in rock garden and on the roof,they all can survive after the continuous drought weather for 28 days,the growing external merits of the 4 Sedum plants order was Sedum aizoon,Sedum emarginatum,Sedum sarmentosum, Sedum yvesii.(4) Sedum yvesii was suitable for cover and forest edge greening,the best irrigation was the water content of soil between 55 percent to 60 percent.Sedum sarmentosum.Sedum emarginatum and Sedum aizoon were suitable for three-dimensional greening, rock garden greening and slope greening, and also can be used in water-saving landscaping as a drought tolerant plants,the best irrigation was the water content of soil between 35 percent to 60 percent.