两种基因型菜心根系形态和生理特性差异对其吸收累积DEHP影响的初步研究

在前期筛选出油青60天菜心和特青60天菜心分别为PAEs高/低吸收累积基因型菜心的基础上,进行邻苯二甲酸二(2-乙基己基)酯(DEHP)不同污染水平的溶液培养试验,对比研究两种基因型菜心的根系形态和生理特性的差异,初步探讨其与菜心吸收累积DEHP的关系.结果表明,随着培养液中DEHP浓度的增加,在根系形态方面,两种基因型菜心根系生物量、总根长和根表面积均下降,油青60天菜心根直径变粗,而特青60天菜心根直径变细;在根系生理特性方面,油青60天菜心除了根系活力下降外,总吸收面积、活跃吸收面积、比表面积和根系脂肪含量均增加,而特青60天菜心除了根系活跃吸收面积增加外,其余指标均下降.因此,两种基因型菜心的根系形态和生理特性对DEHP胁迫响应存在差异.除根直径外,油青60天菜心根系形态和生理指标总体上均高于特青60天菜心,更有利于其根系对DEHP的捕获和吸收.

Root morphological and physiological characteristics of two genotypes of Brassica parachinensis and their effect on di(2-ethylhexyl) phthalate (DEHP) uptake

Two genotypes of Brassica parachinensis,the DEHPhigh-accumulator Youqing-60 and the low-accumulator Teqing-60,were grown in hydroponic systems contaminated with DEHP(20 and 50 mg·L^-1).The morphology and physiology of the roots were measured,and their effects on uptake of DEHPin roots and shoots are discussed.The results showed that the root morphology of the two genotypes varied with DEHPconcentrations in solution.As DEHPconcentration increased in solution,the root biomass,total root length and root surface area of the two genotypes decreased and the root diameter decreased in Youqing-60 but increased in Teqing-60.Similarly,total absorption area,active absorption area,specific surface area and root lipid concentration increased(except root activity)for Youqing-60,while root physiology indexes decreased(except active absorption area)for Teqing-60.In general,the root morphological and physiological indexes of Youqing-60 were higher than those of Teqing-60(except root diameter),which was favorable for uptake of DEHP.