Abstract: In order to explore the differences in cadmium （Cd） enrichment ability and physiological mechanisms among different ryegrass varieties, six ryegrass varieties were used as materials to study the effects of cadmium stress on seed germination, biomass, cadmium absorption, pigment content, photosynthetic characteristics, and stress resistance. The results showed that compared with normal growth conditions, cadmium stress had a low promoting and high inhibiting effect on seed germination and root and shoot growth of different ryegrass varieties. Cadmium stress increased the content of photosynthetic pigments in ryegrass;cadmium stress increased the stomatal conductance, intercellular CO₂ concentration, and transpiration rate of Venus, Benz, and Victoria leaves;cadmium stress increased the POD activity of Benz, Victoria, and Blue Label leaves;cadmium stress increased the SOD activity of Carter and Victoria leaves; cadmium stress increased CAT activity in Victoria and Venus leaves. Benz, Victoria and Venus might have stronger cadmium tolerance than other varieties, thereby reducing the harm of cadmium to themselves;cadmium stress increased the soluble sugar content of all varieties and the proline content of five ryegrass varieties except Carter. Benz, Blue Label and Victoria could produce more osmotic regulatory substances to alleviate the damage caused by cadmium stress;under normal growth conditions, the cadmium content and accumulation in the upper part of rye grassland were relatively low, and the differences between different varieties were relatively small. Cadmium stress significantly increased the cadmium content and accumulation in the upper part of rye grassland, with Benz having the highest cadmium content and accumulation in the upper part, significantly higher than other varieties.In summary, Benz and Victoria had strong cadmium resistance and cadmium enrichment ability, making them the preferred varieties for cadmium contaminated soil remediation.

Key words: cadmium stress, ryegrass（Lolium perenne L.）, seed germination, seedlings, physiological response