The Effect Of H₂O₂ On The Seed Germination Of Artemisia Sphaerocephala

Artemisia sphaerocephala is one of the main air sown sand-fixing plants in desert areas of Gansu and Inner Mongolia in China.It is of great significance to the ecological maintenance and restoration of this area.Hydrogen dioxide is considered as an important seed germination promoter and can improve the stress resistance of some plants during seed germination.In this study,the effects of exogenous addition of H₂O₂ and H₂O₂ scavenger DPI on the germination characteristics of A.sphaerocephala seeds were studied,and the physiological mechanism during the process was explored.The main results are as follows:?1?After exogenous addition of H₂O₂ and DPI,the seed germination characteristics of A.sphaerocephala changed for 7 days:the low concentration of H₂O₂?10 mmol/L?inhibited the seed germination of A.sphaerocephala,the germination rate was 31.60%;the high concentration of H₂O₂?50 mmol/L?promoted the seed germination of A.sphaerocephala,the germination rate was 78.40%;the scavenger of H₂O₂ DPI significantly inhibited the seed germination of A.sphaerocephala,the germination rate was 21.20%,and the compound of H₂O₂?10mmol/L?and DPI and the compound of H₂O₂?50 mmol/L?and DPI both inhibited the seed germination of A.sphaerocephala,the germination rates were 36.00%and39.20%respectively.?2?The changes of ABA,GA₃ content and GA₃/ABA ratio were the main factors affecting the seed germination of A.sphaerocephala.After 48 hours of seed imbibition,the ABA contents increased by the treatments of low concentration of H₂O₂,DPI,and DPI combined with low and high concentration of H₂O₂,which were1.19,1.27,1.12 and 1.14 times higher than that of the control;the GA₃ contents were11.54%,12.65%,21.00%and 22.53%of the control,respectively;the GA₃/ABA ratios were 9.70%,10.03,18.64%and 19.71%of the control,respectively,and then seed germination was inhibited.High concentration of H₂O₂ caused the ABA content decreased,and the content was 54.86%of the control,GA₃ content was 1.30 times of the control,GA₃/ABA ratio was 1.99 times of the control,and then seed germination was promoted.?3?After 48 hours of seed imbibition,for low concentration of H₂O₂ treatment,the activities of SOD,CAT,APX and GR were 1.32,1.20,3.05 and 2.06 times of the control,respectively,and the contents of antioxidants of AsA and GsH were 1.66 and1.48 times of the control,respectively.Because of the elimination of H₂O₂ in the seed,the germination was inhibited.For high concentration of H₂O₂ treatment,the activities of POD,CAT and GR were 55.65%,74.05%and 61.09%of the control,respectively;the content of AsA antioxidant was 96.78%of the control,which may cause the accumulation of H₂O₂ and promote seed germination.