伴生盐生植物对胡杨幼苗的脱盐效应及其生理生态效应

为了筛选适于胡杨(Populus euphratica)幼苗最佳脱盐效果的盐生植物,以1年生胡杨幼苗为试验材料,采用盆栽控盐胁迫的方法,选取新疆常见盐生植物碱蓬(Suaeda glauca(Bunge)Bunge)、盐角草(Salicornia europaea)和盐节木(Halocnermum str)作为伴生植物进行脱盐试验,通过测定胡杨幼苗生理生态指标探讨脱盐作用对其影响规律。结果表明:与对照(CK)相比,胡杨幼苗在伴生盐生植物脱盐作用下株高和地径均增加,且能够保持一定水平的根冠比、根质量比和根宽深比,其中,株高最大增幅由大到小为盐角草(11 g/L)、碱蓬(5 g/L)、盐角草(5 g/L)、CK;地径增量由大到小为盐角草(11 g/L)、盐节木(11 g/L)、碱蓬(5 g/L)、CK;根冠比增幅由大到小为盐角草(11 g/L)、盐节木(11 g/L)、碱蓬(5 g/L)、CK;根质量比较CK(0.48)差异均不大;根宽深比较CK均有所减少。幼苗表观量子效率(α)、最大净光合速率(Pnmax)、暗呼吸速率(Rd)、光饱和点(LSP)较之于CK均升高,光补偿点(LCP)呈相反的趋势;各处理下CO2响应参数相较于CK总体升高,但CO2补偿点则减小。综合各项生理生态指标,3种伴生盐生植物在60 d的时间产生了较为显著的脱盐效果,低盐质量浓度(5 g/L)条件下,伴生碱蓬对胡杨幼苗脱盐效果最佳;中(11 g/L)、高(15 g/L)盐质量浓度条件下伴生盐角草脱盐效果最佳。

Desalination Effect and Physiological and Ecological Effects of Associated Halophytes on Populus euphratica Seedlings

In order to screen the halophyte suitable for the best desalting effect of Populus euphratica seedlings,the 1-year-old P.euphratica seedlings were used as experimental materials,and the salt-bearing salt-control method was used to select the common halophyte in Xinjiang Suaeda glauca(Bunge).Bunge,Salicornia europaea and Halocnermum str were used as the associated plants for desalting experiments.The effects of desalting on the physiological and ecological indexes of P.euphratica seedlings were studied.Compared with the control(CK),the plant height and ground diameter of P.euphratica seedlings increased under the desalination of the associated halophyte,and the root-shoot ratio,root-to-weight ratio and root width-depth ratio could be maintained at a certain level.The maximum increase of plant height from large to small is Salicornia europaea(11 g/L),Suaeda glauca(5 g/L),Salicornia europaea(5 g/L),and CK;ground diameter increment from large to smallis Salicornia europaea(11 g/L),H.str(11 g/L),Suaeda glauca(5 g/L),CK;root to crown ratio from large to small increased as Salicornia europaea(11 g/L),H.str(11 g/L),Suaeda glauca(5 g/L)and CK;root weight comparison CK(0.48)difference is not large;root width and depth compared with CK have reduced.The apparent quantum efficiency(α),maximum net photosynthetic rate(Pnmax),dark respiration rate(Rd)and light saturation point(LSP)of seedlings increased compared with CK,and the light compensation point(LCP)showed the opposite trend.The CO2 response parameter under treatment is higher than that of CK,but the CO2 compensation point is reduced.Based on various physiological and ecological indicators,the three associated halophytes produced a significant desalting effect in 60 d.Under the condition of low salt concentration(5 g/L),the desalting effect of Suaeda glauca on P.euphratica seedlings was the best.The salt desalinization effect of(11 g/L)and high(15 g/L)salt concentration,the Salicornia europaea effect was the best.