Physiological-biochemical characteristics and drought tolerance evaluation of representative plants in Karst areas of Southwest China

ObjectiveThe physiological-biochemical characteristics of four typical plants, such as Lithocarpus variolo-sus,Quercus monimotricha,Photinia prionophylla,Viburnum atrocyaneum in rocky desertification area were studied to evaluate their drought-resistant ability in order to provide references for selecting and allocating suitable varieties for degraded ecosys-tem in rocky desertification areas, and restoring and reconstructing vegetation system. MethodLithocarpus variolosus, Quercus monimotricha, Photinia prionophylla and Viburnum atrocyaneum were used as test materials. The contents of drought tolerance indictors including chlorophyll, soluble sugar, soluble protein, proline, MDA, CAT, and POD in leaves and their correlation were analyzed. Drought-resistant capacity of the four typical plants was comprehensively evaluated using fuzzy function method.ResultDifferent plants displayed different adaptability towards rocky desertification area. The order of total chlorophyll content, chlorophyll a content, chlorophyll b content and CAT activity was Quercus monimotricha>Lithocarpus variolosus> Photinia prionophylla> Viburnum atrocyaneum. The order of total soluble sugar was Photinia prionophylla>Viburnum atrocyaneum>Quercus monimotricha>Lithocarpus variolosus. The order of proline content was Quercus moni-motricha>Photinia prionophylla>Lithocarpus variolosus>Viburnum atrocyaneum. The order of POD activity was Lithocarpus variolosus>Quercus monimotricha>Photinia prionophylla>Viburnum atrocyaneum. The order of MDA content was Viburnum atrocyaneum>Quercus monimotricha>Lithocarpus variolosus>Photinia prionophylla. The order of total soluble protein was Viburnum atrocyaneum>Photinia prionophylla>Quercus monimotricha>Lithocarpus variolosus. Correlation analysis showed that significant positive correlation existed between soluble sugar and total chlorophyll content, POD activity and MDA con-tent, and soluble protein content and CAT activity. Fuzzy function comprehensive evaluation results exhibited that drought-re-sistant capacity order was Quercus monimotricha>Photinia prionophylla>Lithocarpus variolosus>Viburnum atrocyaneum.ConclusionQuercus monimotricha was most adaptive to Yunan rocky desertification area, and then followed by Photinia pri-onophylla and Lithocarpus variolosus, The weakest was Viburnum atrocyaneum.