摘要
高粱抗旱品种3197B比不抗旱品种三尺三在水分胁迫条件下ψ_S下降低。在相同ψ_S时,3197B相对含水量高于三尺三。水分胁迫期间,3197B能始终维持比三尺三较高的ψ_P。在中度和严重水分胁迫时,3197B几种渗透物质积累均高于三尺三,其中可溶性糖和K^+对渗透调节贡献最大。水分胁迫下,3197B正展开叶渗透调节能力较强,ψ_P维持较高,临界膨压低,叶片扩张性能小、故生长速率随ψ_W下降较慢。
The seedlings of two sorghum cultivars, drought-resistant cv. 3197B and drought-sensitive San Chi San, were used in the experiments to study the relationship of osmotic adjustment to the elongation growth of leaves and the contribution of solute accumulation to osmotic adjustment under water stress.
The results showed that the osmotic potential in 3197B was more negative than that of San Chi San under water stress. When RWC was 0.9～1.0, the 3197B osmotic potential decreased to-1.75 MPa, while that of San Chi San decreased to—1.50 MPa. Under moderate or serious water stress, the accumulation of several solutes in 3197B was more than that in San Chi San, in which soluble sugars and K^+ contributed more to osmotic adjustment. Growing leaves of 3197B have stronger osmotic adjustment capacity, hi-g her turgor pressure, and lower threshold turgor and leaf extensibility, thus the leaf elongation rate decreased more slowly with a decrease of water potential. However, in contrast to 3197B the leaves of San Chi San were more sensitive to water deficit.
基金
国家自然科学基金
关键词
高粱
水分胁迫
渗透调节
延伸生长
water stress,water potential, osmotic potential, turgor pressure (pressure potential), osmotic adjustment, elongation growth, sorghum
