Preliminary Studies On Drought Resistance Characteristics Of Kochia Prostrata (L.) Schrad

One-year-old seedlings of Kochia prostrata (L.) Schrad had been used as materials to study the characteristics of drought resistance by potted mode. The morphological indexes, physiological and biochemical indexes were determined under different water stress for systemically evaluating drought-resistant characteristics of Kochia prostrata (L.)Schrad. The inherent relationship of tested indexes was studied by variance analysis, correlation analysis and main components analysis. The indexes related to drought resistance were primarily screened out.The results are as followed:1. Under the four levels of water stress, the sequence of root-shoot ratio was: heavy water stress > moderate water stress > light water stress > normal irrigation.2. The changed trends of the contents of chlorophyll, carotenoid and the ratio of chlorophyll a over chlorophyll b were similar under water stress treatment. Drought stress inhibited the composition of chlorophyll and carotenoid of Kochia prostrata (L.)Schrad, Chl a was more sensitive to drought than that of Chl b.3. On water stress, the membrane of Kochia prostrata (L.)Schrad increased with stress intensity increasing.4. The SOD activities firstly increased, then decreased, reached the highest after 14 days; the concentration of MDA and SS distinctly ascended with stress increasing. The results also showed that there was a negative relationship between the SOD activity and the concentration of MDA.5. Leaf water content gradually decreased with the drought stress days increasing. In the stressed period, the decrease of heavy water stress and moderate water stress was more than that of light water stress and normal irrigation. The significant difference existed among these treatments. The change of water saturation deficiency was increasingly obvious with the enhancement of water stress intensity.6. The growth of seedling was inhibited under water stress, and the enhancement of water stress intensity increased degree of inhibition.7. Through principal components analysis, the relative water content of leaves, leaf water holding capacity, Plasma membrane permeability, activities of SOD, and the content of Chlorophyll, Proline and MDA can be used as main indexes to identify the drought resistance in Kochia prostrata (L.)Schrad.