重金属Cu^(2+)、Cd^(2+)和Pb^(2+)对8种禾草种子萌发和幼苗生长的影响

Effects of Heavy Metals Cu^(2+),Cd^(2+) and Pb^(2+) on Seed Germination and Seedling Growth of 8 Grasses

研究了不同浓度Cu^(2+)(200、300、400和500mg·L-1)、Cd^(2+)(1、50、150和200mg·L-1)、Pb^(2+)(500、1 000、1 500和2 000mg·L-1)对8种禾本科牧草种子萌发和幼苗生长的影响。结果表明:重金属离子胁迫对禾本科植物种子的发芽和幼苗生长的影响因植物种类及重金属离子不同而有差异。随着Cu^(2+),Cd^(2+)和Pb^(2+)浓度的增大,8种禾本科草种的相对发芽率、相对发芽指数和相对活力指数均呈不同程度的下降。供试不同浓度的Cu^(2+),Cd^(2+)和Pb^(2+)对8种植物幼苗生长均有抑制作用,高浓度胁迫下会出现"无根苗"。通过采用性状相对值对本试验进行隶属函数值综合评价,8种禾本科植物耐Cu^(2+)的强弱顺序为:玉米>高丹草>燕麦>黑麦>无芒雀麦>黑麦草>垂穗披碱草>高羊茅,耐Cd^(2+)的强弱顺序为:高丹草>黑麦>玉米>燕麦>无芒雀麦>垂穗披碱草>黑麦草>高羊茅,耐Pb^(2+)的强弱顺序为:高丹草>燕麦>玉米>黑麦>无芒雀麦>垂穗披碱草>黑麦草>高羊茅。

The effects of different concentrations heavy metals ions included Cu^（2＋）（200,300,400 and 500 mg·L-1）,Cd^（2＋）（1,50,150 and 200 mg·L-1）and Pb^（2＋）（500,1 000,1 500 and 2 000 mg·L-1）on the seed germination and seedling growth of eight grasses were studied in this paper with the distilled water as control.The results showed that the heavy metal ion stress on grass seed germination and seedling growth of different plant species and heavy metal varies.With the increase of Cu^（2＋）,Cd^（2＋）and Pb^（2＋）concentrations,the relative germination rate,relative germination index and relative vigor index of eight grasses showed different degrees of decline.The effects of different concentrations of Cu^（2＋）,Cd^（2＋）and Pb^（2＋）on seedling growth of eight grasses are inhibitory,and＂rootless seedlings＂appeared under high concentration stress.Comprehensive evaluations of the resistance of grasses seeds to the metal ions during germination stage were done by membership function method.The order of seed resistance during germination period to Cu^（2＋）stress ranked as Zea mays Sorghum bicolor×Sorghum sudanense Avena sativa Secale cereale Bromus inermis Lolium perenne Elymus nutans Festuca arundinace;to Cd^（2＋）stress was：Sorghum bicolor × Sorghum sudanense Secale cereale Zea mays Avena sativa Bromus inermis Elymus nutans Lolium perenne Festuca arundinace;while to Pb^（2＋）stress was：Sorghum bicolor ×Sorghum sudanense Avena sativa Zea mays Secale cereale Bromus inermis Elymus nutans Loliumperenne Festuca arundinace.