Study On Physiological And Biochemical Indices Of Drought Resistance Of Two Species In Ceratoides

The Ceratoides is the kind of plant that can live in drought or extremeness drought condition. In drought grassland, desertification grassland and desertification area, they have important value in economy and ecology. The Ceratoides is one of the promising drought resisting species for developing natural meadow. In the article, a study was developed on Ceratoides arborescens and Ceratoides lanata by observing some physiological and biochemical indices. The results could be used to evaluate the drought resistance ability, give a guide for C.lanata introduction, and make a function on desert control and water and soil conservation, developing meadow and pasturing by planting plant of the Ceratoides. Some drought-resisting indices were observed in the condition of controlling water supply artificially on potted planting Ceratoides, the results as follows. Leaf water content was gradually decreased with the drought stressed days increasing. In the stressed period, the decrease of C.arborescens's leaf water content was more than that of C.lanata. It showed that C.arborescens could preserve water efficiently. Relative water content was also decreased with the drought stressed days increasing. During the stressed period, relative water content of C.arborescens decreased slowly, there were no significant differences among different days. Relative water content of C.lanata reduced more, the decreasing trend was like a ladder and there was significant difference among days. The change of water saturation deficiency was the other around, unlikely the change of relative water content. It rose gradually. The increase of C.lanata was less than that of C.arborescens. Bound water content was low on normal condition, but it rose on stressed condition. Bound water content of C.arborescens was higher than C.lanata on two conditions. Diurnal change of transpiration rate of two plants had the character of double-climax curve. Transpiration rate were lower in stressed than in normal watering condition. The diurnal average of C.arborescens was higher than C.lanata. The photosynthesis was strong, diurnal trend was a one-climax curve in normal watering condition. In stressed condition, photosynthesis rate decreased distinctly, photosynthesis rate was negative at noon. The trend of diurnal change was double-climax curve; the diurnal average of C.arborescens was higher than that of C.lanata. During the stressed period, the activity of SOD and CAT increased firstly, reached the climax on the sixth day after stressed, then decreased. The activity of SOD and CAT of C.lanata were higher than that of C.arborescens, but the SOD activity of C.arborescens increased more than C.lanata. The proline content was increased in stressed course, reached the climax on the twelfth day. The increasing rate of proline of C.lanata was higher than that of C.arborescens. The content of MDA enhanced with the deeper of stressed, the degree of velum damage of C.lanata was deeper than C.arborescens in prophase of stressed. It is considered that two species in Ceratoides are both plant having strong drought resistance ability, the drought resistance ability of C.arborescens is stronger than C.lanata, by analyzing results of main component analysis and comprehensive appraisal of all indices. But their mechanism of drought resistance is similar.