Study On The Effect Of Active Oxygen On The Germination Of Leymus Chinensis Seeds

Reactive oxygen species（ROS）are closely related to seed dormancy and germination.In this study,Leymus chinensis（Leymus chinensis（Trin.）Tzvel.）seeds were used as the research object,using exogenous reactive oxygen species（ROS）donor methylviologen（MV）,hydrogen peroxide（H₂O₂）,and antioxidants.N-acetyl-L-cysteine（NAC）and abscisic acid（ABA）are used to treat Leymus chinensis seeds,to study their effects on ROS and its antioxidant system during the germination of Leymus chinensis seeds and the effects of ROS on the seed germination process of Leymus chinensis.The location at the tissue level intends to reveal the mechanism of reactive oxygen species（ROS）during the germination of Leymus chinensis seeds and the distribution of ROS in Leymus chinensis seeds.This research is helpful to the utilization of Leymus chinensis germplasm resources,and promoting the germination of Leymus chinensis seeds has important theoretical significance and application value for the construction of artificial grassland and the restoration of grassland desertification in my country.The main findings are as follows:1.In this study,whether low-temperature pretreatment is performed or not,1m M H₂O₂and 0.1μm MV can significantly improve the germination of Leymus chinensis seeds and the growth of seedlings.Without low-temperature treatment,1m M H₂O₂increased the germination rate by 44%,and 0.1μm MV increased the germination rate by 44%;under low-temperature pretreatment conditions,the germination rate was significantly higher than that without low-temperature treatment.1m M H₂O₂increased the germination rate by 16%,and 0.1μm MV increased the germination rate by 16%.The germination rate was 5%,50μm ABA and 5m M NAC significantly inhibited the germination of Leymus chinensis seeds,and the germination rate was less than 10%.2.Regardless of low temperature pretreatment or not,when 5m M NAC and 50μm ABA inhibit seed germination,the use of 1m M H₂O₂and 0.1μm MV can effectively alleviate the inhibition.Compared with 5m M NAC,1m M H₂O₂increases the germination rate by 69%under non-low temperature conditions,and 0.1μm MV increases the germination rate by 40%.Under low temperature pretreatment conditions,1m M H₂O₂increases the germination rate by 70%,and 0.1μm MV increases the germination rate51.%.Compared with 50μm ABA,1m M H₂O₂can increase the germination rate by73%under non-low temperature conditions,and 0.1μm MV can increase the germination rate by 69%;under low temperature pretreatment conditions,1m M H₂O₂can increase the germination rate by 67%,and 0.1μm MV can increase the germination rate by 65%.3.In the determination of antioxidant system,1m M H₂O₂,0.1μm MV,50μm ABA+0.1μm MV can significantly increase the APX,CAT,DHA and GSH enzyme activities,O₂^—rate and H₂O₂content promotion of Leymus chinensis seeds without low temperature treatment.Leymus chinensis seeds germinate.Under low temperature pretreatment conditions,0.1μm MV promotes seed germination by increasing DHAR enzyme activity,GSH content and H₂O₂content.4.According to the chemical localization of H₂O₂cells,the H₂O₂treated with 1m M H₂O₂,50μm ABA+1m M H₂O₂,50μm ABA+0.1μm MV is mainly distributed in the root tip,and there is no H₂O₂accumulation on the stem.However,H₂O₂was widely distributed in the seedlings of Leymus chinensis seeds treated with 0.1μm MV,5m M NAC,50μm ABA,5m M NAC+1m M H₂O₂,5m M NAC+0.1μm MV,mainly at the root tip,but less on the stem tip.