Effects of space mutagenesis on seedling physiological characteristics of alfalfa materials under PEG-6000 simulated drought stress

ZENG Yanxia; CHEN Zhilong; SHA Xiaodi; SHANG Jihong

doi:10.13557/j.cnki.issn1002-2813.2025.16.014

Abstract：The experiment aimed to investigate the effects of space mutagenesis on the seedling physiological characteristics of alfalfa(Medicago sativa)materials under drought stress.Fourteen alfalfa materials(half mutagenized materials and half non-mutagenized materials)were selected,and polyethylene glycol 6000(PEG-6000)was used to simulate drought stress treatment.Set up the non-mutagenized material distilled water treatment(CK1),the non-mutagenized material drought treatment(Ti),the mutagenized material distilled water treatment(CK2),and the mutagenized material drought treatment(T2).Each treatment had two replicates,with 30 seedlings in each replicate.Measured relevant physiological characteristic indicators and used the membership function method for comprehensive evaluation.The results showed that except the relative electrical conductivity of Huangguan in T1 treatment was slightly lower than that in CK1 treatment,the relative electrical conductivities and malondialdehyde(MDA)concentrations of the other materials all increased.Compared with the T1 treatment,the relative electrical conductivities of DS310FY and Yanbao,and the MDA concentration of Yanbao in T2 treatment were significantly decreased(P＜0.05).After drought treatment,the soluble sugar concentrations of most materials decreased,while the proline concentrations increased.Compared with the T1 treatment,the soluble protein concentrations of Gannong NO.3 and Adina,the soluble sugar concentrations of Gannong NO.3 and Yanbao,and the proline concentrations of Yanbao and Adina in the T2 treatment were significantly decreased(P＜0.05),while the soluble sugar concentrations of Juneng 7,Huangguan,WL343 and Adina,and the proline concentration of Huangguan were significantly increased(P＜0.05).After drought treatment,except for Juneng 7 and WL343,the catalase(CAT)activities of the other materials were significantly higher than that of the distilled water treatment(P＜0.05).Compared with the T1 treatment,the superoxide dismutase(SOD)activities of DS310FY,Juneng 7,WL343 and Adina,the peroxidase(POD)activities of Juneng 7 and Yanbao,and the CAT activities of Gannong NO.3,DS310FY and Huangguan in T2 treatment were significantly increased(P＜0.05),while the SOD activity of Yanbao,the POD activities of Gannong NO.3,Huangguan,WL343 and Adina,and the CAT activities of WL343 and Adina were significantly decreased(P＜0.05).Comprehensive analysis of membership found that after drought stress,the mean membership functions of physiological characteristic indicators of mutagenized materials DS310FY,Juneng 7,Huangguan,and WL343 were higher than their corresponding non-mutagenized materials.The study indicates that after space mutagenesis,the drought resistance of seedlings from DS310FY,Juneng 7,Huangguan,and WL343 has been improved.