李慧芳，王瑜，袁庆华*，赵桂琴

(1.中国农业科学院北京畜牧兽医研究所，北京 100193；2.甘肃农业大学草业学院，甘肃 兰州 730070)

铅胁迫对禾本科牧草生长、生理及Pb2+富集转运的影响

李慧芳1,2，王瑜1，袁庆华1*，赵桂琴2

(1.中国农业科学院北京畜牧兽医研究所，北京 100193；2.甘肃农业大学草业学院，甘肃 兰州 730070)

摘要：采用苗期盆栽试验，对14份禾本科牧草种质材料进行不同浓度(0，10，50，100，200，300 mg/kg)铅(Pb)胁迫处理，通过对株高、分蘖数、地上/地下生物量、脯氨酸含量、抗氧化酶(SOD、POD、CAT)活性、地上部与根中Pb2+含量等指标的测定与分析，探究Pb胁迫对禾草生长生理以及Pb2+富集转运的影响。结果表明，随着Pb浓度的增加，14份材料的株高、分蘖数、地上生物量均呈先上升后下降的趋势，地下生物量则逐渐降低，通过综合评价，来自土耳其的长穗冰草G5具有较强的耐Pb性。随着Pb浓度的增加，地上部与根中Pb2+含量逐渐升高，富集系数逐渐降低，转移系数逐渐降低(披碱草G7与G8除外)，根中Pb2+含量显著高于地上部，为Pb2+的主要富集器官，披碱草地上部Pb2+含量高于其他材料，具有较强的Pb富集转运能力。7份材料的生理指标测定结果表明，随着Pb浓度的增加，7份材料的脯氨酸含量逐渐上升，CAT活性逐渐下降，POD和SOD活性则呈先上升后下降的趋势。

关键词：禾本科牧草；苗期；铅胁迫；生长和生理；富集转运

Effects of lead stress on growth, physiology, and lead ion accumulation and transportation in gramineous forages

LI Hui-Fang1，2, WANG Yu1, YUAN Qing-Hua1*, ZHAO Gui-Qin2

1.InstituteofAnimalScienceofCAAS,Beijing100193,China; 2.CollegeofGrasslandScience,GansuAgriculturalUniversity,Lanzhou730070,China

Abstract:Fourteen gramineous forages were stressed by different lead treatments (0, 10, 50, 100, 200, 300 mg/kg) at the seedling stage in pots. By measurement of plant height, tiller number, shoot and root biomass, antioxidant enzyme activities and shoot and root lead ion content, the effects of lead stress on growth, physiology, accumulation and transportation were analyzed. At low levels of lead exposure, plant height, tiller number and shoot biomass were generally increased, then reduced gradually with increasing lead exposure. Agropyron elongatum G5from Turkey was found to have a high lead tolerance. With increasing lead exposure, lead ion content in roots and shoots increased gradually, while the bio-concentration factor and transfer factor decreased gradually except for Elymus dahuricus G7and G8. The content of lead ions in roots was significantly higher than that in shoots, from which we concluded that the root was the main organ by which Poaceous forages accumulate lead ions. The content of lead ions in shoots of E. dahuricus G7and G8were higher than in other germplasm, indicating a high capacity for lead accumulation and transportation. From physiological analysis of seven evaluated varieties, it was found that with increased lead exposure, proline content increased gradually, and catalase (CAT) activity decreased gradually, while peroxidase (POD) and superoxide dismutase (SOD) were elevated at low levels of exposure, but decreased at higher levels of exposure.

Key words:gramineous forages; seedling stage; lead stress; growth and physiology; accumulation and transportation

铅(Pb)是最严重的环境重金属污染物之一[1]。Pb广泛存在于自然界，易被土壤吸附，不易被生物降解。Pb在植物根、茎、叶及籽粒中的累积，不仅严重影响植物的生长发育、降低产量和质量[2]，并通过生物链富集而对人类健康造成严重的威胁，成为环境治理中越来越突出的问题。……