Effects of Mixed Saline Stress on Seed Germination of Taraxacum mongolicum Hand-Mazz
In order to explore the effects of different mixed salt stress on germination of dandelion(Taraxacum mongoli-cum Hand-Mazz)seeds,in this study,dandelion seeds were used as experimental materials,and four mixed salts composed of different concentrations of NaCl(pH=7.20),Na2SO4(pH=8.03),NaHCO3(pH=8.90),and Na2CO3(pH=9.63)were prepared.The concentration ratios of the four salts in the mixed salt were 1∶1∶0∶0(YA),1∶2∶1∶0(YB),1∶9∶9∶1(YC),and 1:1∶1∶1(YD),respectively.Five concentration gradients(25,50 100 150,and 200 mmol/L)were set for each mixed salt,and distilled water was used as the control(CK).Different types of mixed salt solutions were used to simulate the mixed saline-alkali soil con-ditions for the saline-alkali stress treatment of dandelion seeds,and germination and variation of dandelion seeds under alkaline salt stress were analyzed.The results showed that germination of most seeds was negatively affected to a certain extent under mixed salt stress.Under the same mixed salt,the germination rate of seeds decreased significantly with the increase of salt con-centration.When the concentration of the four mixed salts was 25 mmol/L,the seed recovery germination rate was higher after rehydration,and the final germination rate was not significantly different from that of CK.At the same pH value,both the re-covery germination rate and the final germination rate decreased to varying degrees with the increase of salt stress concentration.Under the treatments of YC and YD with high pH values,when the salt concentration was higher than 50 mmol/L,seeds could not germinate.The YD group had a relatively strong inhibitory effect on seed germination,and more than half of the seeds were inactive when the salt concentration was higher than 100 mmol/L.The concentration of the mixed salt solution,pH value,and the interaction between the two,had a significant effect on various germination parameters of seeds.The mixed salt alkali stress in wetland environments had a stronger and inevitable toxic effect on plants than single salt stress.Cultivation of plant seeds under salt stress at the early growth stage could enhance the tolerance to salt alkali and provide a new feasible ap-proach for artificial restoration of saline alkali land.
dandelion(Taraxacum mongolicum Hand-Mazz)salt tolerancesalt alkali stressseed germinationmixed salt
万方数据
维普
