Effects of waterlogging stress on physiological,biochemical,and nutritional indexes of alfalfa

XU Yi; WANG Ting; GUO Yupeng; LI Xin; SHI Pengjun; ZHENG Xia; MIAO Xingfen

doi:10.13557/j.cnki.issn1002-2813.2025.16.015

Abstract：The experiment aimed to explore the effects of waterlogging stress on the physiological characteristics and nutritional quality of alfalfa(Medicago sativa L.).The drought-tolerant variety 416wet and the drought-sensitive variety QST1 were selected as materials.The control(CK)treatment was normally cultivated,while the waterlogging stress treatment(WL)replenished the evaporated water solution every three days to maintain a water level of 2 cm above the soil surface.Samples were collected at 0,1,3,and 5 days after treatment,with three replicates for each treatment.The physiological,antioxidant,and nutritional indicators of alfalfa were measured.The results showed that compared with the CK treatment,the aboveground dry weight of QST1 in the WL treatment was significantly reduced(P＜0.05),and the stem-leaf ratio was significantly increased after 5 days of stress(P＜0.05).The content of chlorophyll a(Chla),chlorophyll b(Chlb),and total chlorophyll(Chi)were extremely decreased(P＜0.01).After 5 days of stress,the Chi content of 416wet in the WL treatment was significantly reduced(P＜0.05).Compared with the CK treatment,the malondialdehyde(MDA)content,superoxide dismutase(SOD),and catalase(CAT)activities of 416wet were extremely increased after 3 days of stress(P＜0.01).After 5 days of stress,the MDA content of 416wet was significantly decreased(P＜0.05),and the SOD activity was extremely increased(P＜0.01).The MDA content of QST1 in the WL treatment was extremely increased after 3 and 5 days of stress(P＜0.01),and the CAT activity was significantly decreased after 1 day of stress(P＜0.05),and extremely increased after 3 and 5 days of stress(P＜0.01).The SOD activity was significantly increased after 5 days of stress(P＜0.05).With the increase of stress time,the content of superoxide anion(·O2-)and hydrogen peroxide(H2O2)in QST1 continued to rise.Compared with the CK treatment,the proline(Pro)content of QST1 in the WL treatment was significantly decreased after 5 days of stress(P＜0.05),while the Pro content of 416wet in the WL treatment continued to increase.Compared with the CK treatment,the crude fiber(CF)content of 416wet in the WL treatment was significantly decreased(P＜0.05),and the crude ash(Ash)content and gross energy(GE)were significantly increased(P＜0.05).The crude protein(CP),CF,and Ash concentrations of QST1 in the WL treatment were significantly decreased(P＜0.05).The study shows that the drought-tolerant variety 416wet has strong growth stability and high forage value under waterlogging stress,providing a reference for the selection of alfalfa varieties in areas with frequent waterlogging in the south.