土壤水分胁迫下四翅滨藜的生长及生物量分配特性

Growth and Biomass Distribution Characteristics of Atriplex canescens(Pursh) Nutt under Different Soil-water Stress in Desert Areas

从美国西部引进2年生准常绿灌木四翅滨藜(Atriplex canescens(Pursh)Nutt)分别定植于含水量不同的陶瓷花盆土壤中,通过人工控制土壤水分研究其生长和生物量的分配特性。研究结果表明:土壤水分胁迫严重限制了四翅滨藜的营养生长和生殖生长,使单株高度、分枝数、侧根数和叶片数量显著下降,从而导致单株生物量降低,其中轻度土壤水分胁迫平均苗高为47.3 cm,分别是中度、无、重度土壤水分胁迫的1.13、1.31、1.34倍;轻度土壤水分胁迫平均地茎为14.76 mm,分别是中度、无、重度土壤水分胁迫的1.16、1.47、1.50倍;中度、重度和无土壤水分胁迫比轻度土壤水分胁迫的叶干重生物量降低了23.99%、51.76%、47.97%;中度、重度和无土壤水分胁迫比轻度土壤水分胁迫的茎干重生物量降低了15.43%、50.52%、49.59%。随着土壤水分胁迫的加重,光合产物积累从中下部叶片向中上部叶片转移。各构件生物量随土壤水分胁迫的加重而降低,其变化幅度大小为:侧根生物量>叶生物量>茎生物量>主根生物量,反映了四翅滨藜对土壤水分胁迫响应的整体性。

Two-year old plants ofAtriplex canescens （Pursh） Nutt introduced from the west of America were planted at China flowerpots under the different moisture contents at soil in pot. Plant growth and biomass distribution characteristics were researched. The research showed that the nutrition and breeding growth of Atriplex canescens were both seriously limited by soil water stress, which made the plant height, number of branch, number of branch root and leaf as well as plant biomass reduced obviously. The average plant height and base diameter were 47.3 cm and 14.76 cm under the light soil moisture coerced situation, its height was 1.13, 1.31 and 1.34 times and base diameter was 1.16, 1.47, 1.5 times of those of middle, no and heavy soil moisture coercing, respectively. The leaf dry matter and stem dry matter under the middle, heavy and no soil moisture coercing were reduced by 23.99 %, 51.76 %, 47.97 % and 15.43 %, 50.52 %, 49.59 % than those of light ones respectively. With the increasing of soil moisture coercing, photosynthesis accumulation transformed from middle-lower leaves to middle-up ones and the biomasses of component parts reduced with the increasing of soil moisture coercing. The change width was biomass of branch roots 〉 leaves 〉 stems 〉 main root, which indicated that the plant system reaction under soil moisture coercing.