碱胁迫对碱蓬种子萌发及幼苗生长的影响

Effects of alkaline stress on seed germination and seedling growth of Suaeda salsa

种植适应生长条件的植物是改良和利用苏打盐碱地的重要措施。为探讨碱蓬的耐碱范围和耐碱特性,将Na HCO3和Na2CO3按9∶1的摩尔比混合,设0(CK)、50、100、150、200、250 mmol/L共6种处理浓度,分别以蒸馏水和苏打盐碱土为培养基质,比较碱蓬种子萌发和幼苗生长状况的差异。研究结果表明:在水培试验中,碱液浓度>150 mmol/L时,碱蓬种子的发芽势、发芽率和发芽指数显著低于CK;碱液浓度>100 mmol/L时,胚芽长、胚根长和种子活力指数显著低于CK。在土培试验中,碱液浓度>200 mmol/L时,碱蓬种子的发芽率和成苗率较CK分别显著降低19.36%和38.10%;50和100 mmol/L碱液处理条件下,碱蓬的幼芽长较CK分别显著增加23.82%和19.96%;当碱液浓度>50 mmol/L时,碱蓬的幼根长较CK显著降低。冗余分析结果表明,EC值和总碱度是影响碱蓬生长的主要因素,对其解释程度分别为48%和41.1%,且与碱蓬各生长指标存在显著的负相关。综上,碱蓬种子萌发和幼苗生长能够耐受一定程度的碱胁迫,以苏打盐碱土为培养基质的耐碱范围高于水培。

[Background]The salt composition of soda saline-alkali soil is dominated by Na2 CO3 and NaHCO3.This type of soil has both salinization and alkalization characteristics.It not only is of strong alkalinity,but also has poor physical and chemical properties,which severely restricts local agricultural production.Planting vegetation adapting to the growth site conditions of soda saline-alkali land is an important measure for the improvement and utilization of soda saline-alkali land.The purpose of this study is to investigate the alkali-tolerant range and alkali-resistance properties of Suaeda salsa.[Methods]Using S.salsa seeds as test materials,NaHCO3 and Na2 CO3 were mixed at a molar ratio of9∶1,and a total of 6 treatment concentrations of 0(CK),50,100,150,200,and 250 mmol/L were set,respectively.And the experiments was carried out with two culture media of distilled water and soda saline-alkali soil,and the difference of seed germination and seedling growth status of S.salsa were analyzed.[Results]1)In the experiment with distilled water as the culture medium,the germination potential,germination rate and germination index of S.salsa seeds were significantly lower than that of CK when the alkali concentration was>150 mmol/L,and the length of the embryo,the length of the radicle and the seed vigor index were significantly lower than that in CK when the alkali concentration was>100 mmol/L.2)In the experiment with soda saline-alkali soil as the culture medium,when the alkali concentration was>200 mmol/L,the germination rate and seedling surviual rate of S.salsa seeds significantly reduced by 19.36%and 38.10%compared with CK,respectively;under 50 and 100 mmol/L alkali concentration treatment conditions,the young shoot length significantly increased by23.82%and 19.96%compared with CK,and the young root length of S.salsa was significantly lower than that of CK when the alkali concentration was>50 mmol/L.3)The results of redundancy analysis showed that soil EC value and total alkalinity were the main factors affecting the growth of S.salsa,and the degree of interpretation was 48%and 41.1%,respectively;and there was a significant negative correlation with the growth indexes of S.salsa.[Conclusions]The seed germination and seedling growth of S.salsa can tolerate a certain range of alkali stress,and the alkali resistance range of S.salsa in the soda saline-alkali soil is higher than that in distilled water.