Effects of Pelargonium graveolens Hydrosol on Seed Germination and Seedling Growth of Tobacco under Heavy Metal Stress

Guan Jiao; Wang Lihua; He Yi; Bao Zhijuan

doi:10.14083/j.issn.1001-4942.2025.10.007

Abstract：To study the effects of Pelargonium graveolens hydrosols on seed germination and seedling growth of tobacco under heavy metal stress,K326 seeds were used as the experimental materials.The seeds were treated with 0,1％,5％,10％and 15％P.graveolens hydrosol under blank,Cr stress and Cd stress treatments.The seed germination,seedling growth quality,and allelopathic effects were measured.The results indicated that the P.graveolens hydrosol exhibited an allelopathic effect of promotion at low concentration and inhibition at high concentration on the seed germination and seedling growth of tobacco.When the concentra-tion was 5％,the root length and shoot length were significantly higher than those of the control group(CK)by 24.32％and 23.09％,and their allelopathic effect indexes were 19.56％and 18.76％.However,at the con-centration of 15％,the allelopathic effect index on germination potential,root length and shoot length reached-40.82％,-23.21％and-19.27％,indicating strong inhibition.Under Cr stress,the addition of 5％P.graveolens hydrosol showed the best mitigating effects on seed germination and seedling growth;the germina-tion potential,root length,shoot length and dry weight were significantly higher than those of the Cr treatment by 11.33％,111.28％,110.66％and 22.93％,and their allelopathic effect index reached 10.18％,52.67％,52.53％and 18.65％.Under Cd stress,the addition of 10％P.graveolens hydrosol showed the best mitigating effects on seed germination and seedling growth;the germination rate,root length,shoot length and dry weight were significantly higher than those of the Cd treatment by 4.32％,87.95％,70.22％and 42.86％,and their allelopathic effect index reached 7.29％,46.79％,41.25％and 30.00％.In conclusion,an appropriate con-centration of P.graveolens hydrosol significantly promoted seed germination and seedling growth of tobacco un-der both conventional and heavy metal stress conditions with the promoting effect on seedling growth higher than seed germination.These results could provide the technical reference for the application of P.graveolens hydrosol in tobacco heavy metal control.