GC-MS Analysis of Membrane-Graded Fulvic Acid and Its Activity on Promoting Wheat Seed Germination

摘要

The chemical composition of fulvic acid (FA) with a molecular weight below 500 (FA-500) was analyzed, and its activity on promoting the seed germination of wheat was studied in this paper. The FA-500 was obtained by membrane separation technology and qualitatively and quantitatively analyzed by using gas chromatography-mass spectrometry combined with the retention index. Forty-seven constituents were identified, including structures with ester, acid and alcohol groups, which accounted for 95% of the total composition. The highest relative content of compounds was diethyl succinate and diethyl malonate, accounting for 29% and 17% of the total, respectively. Yannong 19 and Luyuan 301 wheat seeds were steeped with the FA-500 solution of different concentration respectively for two hours. Several markers were assessed: germination rate, coleoptile and radicle length, germination index, vitality index and the activity of alpha-amylase and (alpha+beta) amylase. The results indicated that FA-500 had a significant effect on promoting seed germination within an appropriate concentration range. The best concentration was 0.5%, and an inhibiting effect would appear with the increase of concentration. In the process of seed germination, FA-500 may affect the growth of the seed through influencing the amylase activity, which was related to respiration.