Abstract: The inhibitory effects of Cu²⁺, Zn²⁺, Pb²⁺ and Cd²⁺ stress on the seed germination and root elongation of Kentucky bluegrass (Poa pratensis), perennial ryegrass (Lolium perenne), tall fescue (Festuca elata) and white clover (Trifolium repens) were studied. The purpose was to provide a reference for the research of turf grass suitably planted in heavy metal pollution soil. Results showed that Kentucky bluegrass had poorer resistance to tested heavy metals and its relative seed germination rate was lower than CK under heavy metal stress (P<0.05). The lethal dose of Cu²⁺ was only 400 mg稬^-1 (Grade 3 of soil quality standard). Although the relative germination rates of Perennial ryegrass were lower than CK (P<0.05), most seeds could germinate. The relative germination rate of Tall fescue under Zn²⁺ stress reached 102.8% which was significantly higher than CK, and showed a similar change pattern to that of Perennial ryegrass. White clover had poor tolerance to tested heavy metals except Cd²⁺. The relative germination rates of 4 turfgrass types reduced with the increase of stress concentration. The heavy metal stress showed more inhibitory effects on radical growth than plumule growth. The germination and vigor indices of 4 turfgrass types showed a decreasing trend with the increase of stress concentration, and were significantly lower in the most treatments than CK (P<0.05), which indicated that heavy metal had negative impact on the seed germination and vigor of 4 turfgrass types.

Key words: Heavy metal ions, Stress, Turfgrass, Seed germination

摘要： 通过发芽试验探讨Cu²⁺, Zn²⁺, Pb²⁺, Cd²⁺共4种重金属离子胁迫对草地早熟禾(Poa pratensis)、多年生黑麦草(Lolium perenne)、高羊茅(Festuca elata)和白三叶(Trifolium repens)种子萌发的影响,旨在为重金属污染土壤中草坪草种植的适宜性研究提供参考。结果表明:草地早熟禾对各重金属离子抗性较差,其相对发芽率均显著低于对照(P<0.05),其中Cu²⁺浓度为400 mg·L^-1时(土壤环境质量3级标准)已达致死剂量;多年生黑麦草对4种重金属离子表现出不同程度的抗性,虽然其相对发芽率均显著低于对照(P<0.05),但仍有大部分种子顺利发芽;高羊茅在Zn²⁺为1100 mg·L^-1处理下其相对发芽率达102.08%,显著高于对照(P<0.05),且各处理下其相对发芽率变化趋势与多年生黑麦草类似;白三叶除对Cd²⁺抗性较强外,对其余3种重金属离子抗性均较差;4种草坪草相对发芽率均随处理浓度升高而逐渐降低。重金属离子对胚根的抑制作用高于胚芽。4种草坪草种发芽指数和活力指数均有随着重金属离子浓度升高而逐渐降低的趋势,且多数处理下均显著低于对照(P<0.05),说明重金属离子对种子萌发和活力有较大影响。

关键词: 重金属离子, 胁迫, 草坪草, 种子萌发