四种灌木幼苗对水分胁迫的生长响应

Response of Seedling Growth of Four Shrub Species to Water Stress

柠条锦鸡儿(Caragana korshinskii)、白皮锦鸡儿(C.leucophloea)、刺叶锦鸡儿(C.acanthophylla)和长枝木蓼(Atraphaxis virgata)在植被恢复中具有潜在价值,可作为荒山绿化的先锋植物种。通过人工控制水分,比较4种灌木幼苗对干旱胁迫的生长响应。结果表明:幼苗的株高、基径、生长率和生物量均随着水分胁迫的加剧而降低,柠条锦鸡儿和长枝木蓼在水分胁迫下各指标的减少量较白皮锦鸡儿和刺叶锦鸡儿明显。幼苗在干旱胁迫下将生物量更多的分配给根系,幼苗的根冠比增加,光合生物量比基本维持恒定,长枝木蓼的根冠比基本不变。4种灌木对干旱均有一定的耐受能力,其排序为:白皮锦鸡儿>刺叶锦鸡儿>柠条锦鸡儿>长枝木蓼。

Caragana korshinskii, C. leucophloea, C. acanthophylla and Atraphaxis viragata have a potential value in vegetation regeneration, and they can be selected as the pioneer species in afforestation. In this study, the response of seedling growth of these 4 shrub species to artificially simulated drought stress is researched. The results show that water stress impacted significantly the seedling height, basal diameter, growth rate, biomass and their distribution of the 4 shrub species. With increasing water stress, the growth speed of the seedlings of the 4 shrub species was decreased. Reduction of these indexes of C. korshinskii and A. virgata was higher than that of C. leucophloea and C. acanthophylla. Biomass of all the seedlings was mainly contributed by roots under drought stress, so that the root-canopy ratio was increased except that of A. virgata. Moreover, the photosynthetic biomass ratio of seedlings of the 4 shrub species maintained basically with increasing water stress. The study also results reveal that the drought resistance of the 4 shrub species was in an order of C. leucophloe 〉 C. korshinskii 〉 C. acanthophylla 〉 A. virgata.