干旱胁迫对梭梭生长特性的影响

Effects of Drought Stress on Growth Characteristics of Haloxylon ammodendron

为考察干旱胁迫对梭梭生长特性的影响,以凉州地区的梭梭为研究对象,分别考察了干旱胁迫条件下同化枝气孔导度、同化枝含水量、土壤含水量、脯氨酸、可溶性糖浓度以及叶绿素变化情况。结果显示:开花期间5月30日、6月15日的气孔导度最大,土壤含水量最高,同化枝含水量最高,同化枝处于轻度干旱胁迫状态;花期过后高温干旱的夏季来临,梭梭进入花后生殖休眠期,同化枝含水量下降,气孔导度也迅速降低,同化枝呈现萎蔫,处于重度干旱胁迫状态。植物开花期间,可溶性糖作为营养物质从同化枝转移到花器官,降低了同化枝中可溶性糖的含量。而此时同化枝处于轻度水分胁迫状态,脯氨酸含量先于可溶性糖含量略有上升。6月30日—7月30日盛夏期间,同化枝处于重度水分胁迫状态下,可溶性糖与脯氨酸迅速积累,通过渗透调节作用适应干旱胁迫。随后可溶性糖与脯氨酸含量持续保持较高水平状态,未出现明显下降趋。

In order to investigate the effects of drought stress on the growth characteristics of Haloxylon ammodendron,the changes of stomatal conductance,water content,soil water content,proline,soluble sugar concentration and chlorophyll of Haloxylon ammo‐dendron in Liangzhou area were investigated.The results showed that the stomatal conductance was the highest on May 30 and June 15,and the soil moisture content was the highest.The moisture content of the anabolic branch was the highest,and the anabolic branch was under mild drought stress.After flowering,the hot and dry summer comes,and Haloxylon ammodendron enters the post flowering reproductive dormant period.The water content and stomatal conductance of the anabolic branches decrease rapidly,and the anabolic branches are wilting and under severe drought stress.During flowering,soluble sugars were transferred from the anabol‐ic branches to the flower organs as nutrients,which reduced the content of soluble sugars in the anabolic branches.However,the con‐tent of proline increased slightly before the content of soluble sugar when the assimilated branch was under mild water stress.During the summer period from June 30 to July 30,soluble sugar and proline accumulated rapidly under severe water stress and adapted to drought stress through osmotic regulation.Subsequently,the contents of soluble sugar and proline remained at a high level,and there was no obvious decreasing trend.