盐胁迫对杜梨吸收根生长指标的影响

Effects of salt stress on the growth index of absorbing roots of Pyrus betulifolia

[目的]杜梨作为我们北方重要的经济树种资源,本文旨在研究其生长发育常受到盐胁迫的影响。[方法]本研究以2年生杜梨(Pyrusbetulifolia)幼苗为材料,研究不同盐胁迫(0%、0.15%、0.45%NaCl)条件对其吸收根、碳同化及水分利用效率的影响。[结果]盐胁迫会显著抑制吸收根(直径<0.5 mm)的根长、表面积、体积、根长密度及根尖数量以抑制杜梨整体根系的生长发育,但盐胁迫对根系平均直径及其它细根(0.5 mm<直径<2.0 mm)的根长密度影响并不显著。此外,盐胁迫处理后,杜梨光合速率、气孔导度、蒸腾速率、水分利用效率受到严重抑制,吸收根中的可溶性糖和淀粉含量亦显著小于对照。[结论]本研究揭示了盐胁迫对杜梨吸收根⁃碳同化⁃水分利用效率的影响,为研究非生物胁迫对植物的影响提供了新思路。

[Objective]As an important economic tree resource in northern China,the growth and development of Pyrus betulifolia are often affected by salt stress.[Methods]In this study,two-year-old P.betulifolia seedlings were used as materials to investigate the effects of different salt stress levels(0,0.15%,0.45%NaCl)on the absorbing root system,carbon assimilation and water use efficiency of the plants.[Results]The results showed that salt stress significantly inhibited the growth of absorbing root(diameter<0.5 mm),including the root length,surface area,volume,root length density and the number of root tips,which resulted in the inhibition of the growth and development of whole root system.However,no significant effects on root diameter and root length density of other fine roots(0.5<mmdiameter<2.0 mm)were detected.In addition,after salt stress treatment,the photosynthetic rate,stomatal conductance,transpiration rate and water use efficiency of P.betulifolia were severely inhibited,and the contents of soluble sugar and starch in absorbing roots were significantly lower than those of the control group.[Conclusion]This study revealed the effects of salt stress on the root absorption-carbon assimilation-water use efficiency of P.betulifolia,providing a new idea for studying the effects of abiotic stress on plants.