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

This article takes six species of crassulaceae plant for the research object. Studies in arid forces about the six kinds of plants exterior shape change, the Physiological target change as well as six kind of Plants`s, leaf blade dissection struetural change. The research structure indicated that:1. In 20 days after severe drought stress, soil water content has fallen to about 1.12%. At this time Sedum reflexum and Hylotelephium spectabile Boreau have wilting leaves, but the stems are more erect, there are signs of the growth of micro. Sedum kamtschat icum Fisch and the yellow S. hybridum'Immmergrunchell'leaves of nearly all are wilting, some leaves started to fall, growth almost stopped. the rad S. hybridum'Immmergrunchell'and Sedum spurium'Voodoo'a lot of leaves wither and fall off, some branches also appear wither the death.2. Under drought stress, Sedum reflexum,Hylotelephium spectabile Boreau and Sedum kamtschat icum Fisch cell membrane damage were more light than the rad S. hybridum'Immmergrunchell', the yellow S. hybridum'Immmergrunchell'and Sedum spurium'Voodoo'. Proline content in the first 3 persons with sustained drought stress increased ability to regulate the later three kinds of strong. Soluble sugar content in various Sedum quite different. Hylotelephium spectabile Boreau and Sedum kamtschat icum Fisch have new resilience protein production. Comprehensive analysis of Eight Sedum: Sedum reflexum,Hylotelephium spectabile Boreau and Hylotelephium spectabile Boreau drought resistance were higher than. the rad S. hybridum'Immmergrunchell', the yellow S. hybridum'Immmergrunchell and Sedum spurium'Voodoo'.3. Under drought stress, Sedum reflexum and Hylotelephium spectabile Boreau in water saturation deficit and leaf water holding capacity of the two drought indicators have shown a weak drought resistance, but in the adorbent water and free water in the ratio of this indicator has shown strong drought resistance. Hylotelephium spectabile Boreau in osmotic potential and leaf water was demonstrated in both have shown strong drought resistance.4. Six belong to CAM type Sedum plants have stomata distribution of its upper and lower epidermis, stomata are varied type, leaf epidermis are covered with a thin layer of cuticle. These mesophyll cell of Sedum were undifferentiated palisade and spongy tissue. mesophyll cells also contain large quantities of colloidal material and the crystal particles.Through the observation of the growth state of Sedum combined physiological, morphological characters for each of the Sedum ,The Sedum will be divided into three categories according to drought resistance :the stronges drought resistance is Sedum reflexum and Hylotelephium spectabile Boreau, the yellow S. hybridum'Immmergrunchell'and Sedum kamtschat icum Fisch have medium drought resistance, the weakest drought resistance is the rad S. hybridum'Immmergrunchell'and Sedum spurium'Voodoo'.