Studies On Drought Resistance And The Physiological Mechanism In Some Species Sedum L.

The research utilized eight different species of sedum( S.reflexum cv.,Sedum erythrostictum,S.aizoon L.,S. kamtschaticum,S. new kamtschaticum,S.spurium'Voodoo',tow S. hybridum Immergrunchell)as test materials. Determination of physiological-biochemical indexes under drought and observation of growth were studied.The mean results as follows:1.Under drought stress, soil moisture content of all the varieties of sedum was decreased.2.Under drought stress, the relative water content of sedum.L leaves were keeping down. The relative water content of cS.reflexum cv. and Sedum erythrostictum droped slowly ,While the other species of sedum droped comparatively fast.3.Under drought stress ,chlorophyll contents of the eight different species of sedum were rised. The chlorophyll contents of cS.reflexum cv. and Sedum erythrostictum increased slowly, while the other species of increased comparatively fast.4.Under drought stress, the contents of soluble sugar and Pro increased. The contents of soluble sugar of the new S. kamtschaticum increased fastest. The contents of soluble sugar of S.reflexum cv. and Sedum erythrostictum decreased first and then increased.The contents of soluble protein decreased general. The contents of soluble protein of S.reflexum cv,S.aizoon L,Sedum erythrostictum,S. kamtschaticum increased a little first and then decreased., while the other four species of sedum were keeping down sharply.5.Protective enzyme activity of all the species of Sedum increased first and then decreased. The SOD activity of S.reflexum cv. was higher, the POD activity of Sedum erythrostictum was higher , the CAT activity of S.aizoon L. was higher. The changes of protective enzyme activity of 8 species were varied.Three protective enzyme activity were evaluated comprehensively by subordinate function analysis .Results show that:S.reflexum cv. >Sedum erythrostictum>S.aizoon L.>S. kamtschaticum> the red S. hybridum'Immergrunchell'> the yellow S. hybridum'Immergrunchell'> the new S. kamtschaticum>S.spurium'Voodoo'.6.The drought resistance indexes of all the eight species of sedum were interdependence, connect each other. The single index can't reflect the difference of drought resistance between all the species. Ten physiological mechanism were evaluated comprehensively by subordinate function analysis .Results show that:S.reflexum cv. >Sedum erythrostictum>S.aizoon L.>S. kamtschaticum> the red S. hybridum'Immergrunchell'> the yellow S. hybridum'Immergrunchell'> S.spurium'Voodoo'. >the new S. kamtschaticum...