PAEs污染下2种基因型菜心根际土壤微生物特征及差异性

The microbial characteristics and differences in rhizospheric soils contaminated with PAEs grown high/low PAEs accumulation genotypes of Brassica parachinensis.

设置邻苯二甲酸酯(PAEs)3个污染水平(T1,T2,T3)和对照处理(T0),盆栽2种基因型菜心(油青60天菜心和特青60天菜心),研究2种菜心不同生长期根际土壤微生物生物量碳氮(Cmic、Nmic)和总体代谢活性(AWCD)的动态变化特征及差异性,初步揭示2种菜心吸收累积PAEs差异的根际微生态机理.结果表明,2种菜心根际土壤Cmic分别介于84.45～213.30mg/kg和98.33～229.85mg/kg,Nmic分别介于9.00～25.86mg/kg和12.69～34.36mg/kg,显著高于未种植物的处理.AWCD值分别介于0.744～1.075和0.847～1.318,特青60天菜心显著高于未种植物的处理.2种基因型菜心相比,特青60天菜心根际土壤Cmic,Nmic以及AWCD值均大于油青60天菜心(T3处理开花期除外),部分处理间差异显著.2种基因型菜心茎叶和根系中PAEs含量与Cmic、Nmic和AWCD之间的相关性均未达到显著程度,说明2种基因型菜心茎叶和根系中PAEs含量可能与其他因素有关.

Two genotypic cultivars of Brassica parachinensis,Youqing-60（high PAEs-accumulation） and Teqing-60（low PAEs-accumulation）,were cultivated in the soils spiked with three levels（20,50 and 100mg/kg） of dibutyl phthalate and di（2-ethylhexyl） phthalate to investigate the microbial biomasses and metabolic activities in rhizospheric soils at four growth stages of Brassica parachinensis.The results showed that the microbial biomass C（Cmic） in rhizospheric soils of Youqing-60 and Teqing-60 ranged from 84.45 to 213.30mg/kg and 98.33 to 229.85mg/kg,and their microbial biomass N（Nmic） varied from 9.00to 25.86mg/kg and 12.69 to 34.36mg/kg,respectively,which were significantly higher than those in soils without plant.Their average well color development（AWCD） values ranged from 0.744 to 1.075 and 0.847 to 1.318,respectively,which of Teqing-60 were significantly higher than those in soils without plant.Moreover,Cmic,Nmic and AWCD in soils grown cultivar Teqing-60 were higher than those of Youqing-60（except for treatment of T3 at flowering stage）,and significant differences were observed between some treatments.PAEs concentrations in shoots and roots of two genotypes of Brassica parachinensis were not significantly negatively correlated with Cmic,Nmic and AWCD values,indicating that PAEs concentrations in shoots and roots of two genotypes of Brassica parachinensis may be related to other factors.