Abstract: Seventy-three widely collected annual ryegrass (Lolium multiflorum) germplasm resources were used to comprehensively evaluate their seed germination characteristics under different concentration of Pb (NO₃)₂ solutions,which would provide a basic information for the screening of Pb tolerant germplasm and genetic improvement of annual ryegrass. Results showed that all germination indexes except for root length displayed a promotion at low Pb concentration while an inhibition at high Pb concentration under Pb stress. The inhibition effect of Pb stress on root length was stronger than that on shoot length. When the concentration of Pb treatment reached 1 200 mg·L^-1,the average root length was only 3.65% of that root length in the control. The Pb tolerance of annual ryegrass germplasm resources had an extensive variability,which displated more prominent under the treatment of higher concentrations (800 mg·L^-1,1 200 mg·L^-1). According to the membership function and cluster analysis,73 genotypes could be divided into four different Pb resistant groups,namely high resistance (3 materials),moderate resistance (11 materials),low resistance (35 materials) and sensitive type (24 materials).

Key words: Annual ryegrass, Pb tolerance, Germination stage, Membership function

摘要： 本研究以广泛收集的73份多花黑麦草(Lolium multiflorum)种质资源为试验材料，用不同浓度Pb(NO₃)₂溶液进行处理，通过测定种子萌发特性变化进行耐铅性综合评价，以期为多花黑麦草耐铅种质筛选和遗传改良研究提供参考依据。结果表明：铅胁迫下，除了根长，多花黑麦草各萌发指标表现出“低促高抑”的现象；铅胁迫对根长的抑制作用强于芽长，当铅处理浓度达到1 200 mg·L^-1时平均根长仅为对照的3.65%；多花黑麦草种质资源的耐铅性具有广泛的变异性，在较高浓度(800 mg·L^-1,1 200 mg·L^-1)处理下更加凸显。通过隶属函数和聚类分析，可将73份多花黑麦草分为4组不同耐铅类型，即高抗材料3份、中抗材料11份、低抗材料35份和敏感材料24份。

关键词: 多花黑麦草, 耐铅性, 萌发期, 隶属函数