Abstract:

[Objective] To investigate the effects of different saline-alkali stresses on germination of wild soybean seeds collected in Hinggan League of Inner Mongolia, and to provide references for the development and utilization of high-quality wild soybean germplasm resources. [Method] Wild soybean seeds were treated with saline or alkali stresses using NaCl solution （20, 40, 80 and 120 mmol/L）, Na₂SO₄ solution （10, 20, 30 and 40 mmol/L）, and Na₂CO₃ solution （20, 40, 60 and 120 mmol/L）, respectively, and the seeds with no saline-alkali stress treatments were served as control group （CK）. Three replicates were set for each concentration of each solution, with 50 seeds per replicate. The seed germination rate, germination potential, germination index, vigour index, relative injury rate, as well as the seedling root length and seedling length of the seeds treated with the above three solutions were determined and statistically compared. [Result] When the wild soybean seeds were treated with NaCl solution, the highest germination rate, germination potential, germination index and vigour index as well as the lowest relative injury rate were observed in 80 mmol/L treatment group; the seedling root length and seedling length decreased with the increase of NaCl concentrations; the seedling root length and seedling length of 80 and 120 mmol/L treatment groups were significantly （P<0.05） lower than those of 20 and 40 mmol/L treatment groups. When the wild soybean seeds were treated with Na₂SO₄ solution, the highest germination rate, germination potential, germination index and vigour index as well as the lowest relative injury rate were found in 30 mmol/L treatment group; the seedling root length and seedling length decreased with the increase of Na₂SO₄ concentrations; the seedling root length and seedling length in 10 mmol/L treatment group were the longest, with no significant （P>0.05） difference compared to CK. When the wild soybean seeds were treated with Na₂CO₃ solution, the germination rate, germination potential, germination index and vigour index gradually decreased with the increase of Na₂CO₃ concentrations, while the relative injury rate exhibited the adverse trend; the germination rate, germination potential, germination index and vigour index in 120 mmol/L treatment group were 0, and the relative injury rate was 100%; there was no significant （P>0.05） differences in germination rate, germination potential, germination index and vigour index between 20 mmol/L treatment group and CK. [Conclusion] Low intensity of saline-alkali stresses minorly affected the germination indexes of wild soybean seeds collected in Hinggan League, and a certain range of intensities of weak alkali or neutral salt were capable of promoting their germination; different intensities of saline-alkali stresses had an effect on the growth traits of wild soybean seedling, the higher the concentrations, the greater the damages.

Key words: saline-alkali stresses, wild soybean, seed germination