Physiological and Biochemical Changes in the Seeds of Naturally Aged Wenling Medic (Medicago polymorpha) with Its Recovery of Viability

Abstract

Wenling Medic (Medicago polymorpha) is common in southern China and has long been utilized as a vegetable in eastern China, as well as a significant raw ingredient for livestock and pickled meals. As a legume, there is still a research vacuum, and the first problem Wenling Medic faces in production is the problem of seed germination. The germination percentage of Wenling Medic was low, according to production practice and laboratory tests performed in this work. Furthermore, after more than two years of storage, the germination percentage of Wenling Medic dropped sharply, and it lacked a long enough seed life. An attempt was made to restore the viability of the seeds using the polyethylene glycol (PEG) osmoregulation-mediated priming method, after the physiological and biochemical characteristics of the seeds were assessed using the anthrone method, Bradford assay, 3,5-dinitrosalicylic acid (DNS) method, and thiobarbituric acid (TBA) method. The findings showed that it has a relatively short storage age and, with a useable life of only two years under normal aging circumstances, is not deactivated soon after harvesting. In addition, whereas protein content and α-amylase concentration did not significantly correlate (p > 0.05) with storage life, the conductivity of exudate, malondialdehyde content, and carbohydrate content did (p < 0.05). The seed viability was not considerably increased by the saturation initiation mediated by osmoregulation, utilizing PEG. In conclusion, the decrease in Wenling Medic seeds’ germination ability was substantially connected with higher levels of lipid peroxidation and decreased carbohydrate levels, but not with protein concentrations or α-amylase activity. The timing of dehydration may need to be carefully controlled when using PEG osmoregulation to prime Wenling Medic seeds.