• Improved Germination and Seedling Growth of Echinochloa crus-galli var. frumentacea in Heavy Metal Contaminated Medium by Inoculation of a multiple-Plant Growth Promoting Rhizobacterium (m-PGPR)
  • Lee, Ah-Reum;Bae, Bum-Han;
  • Department of Civil & Environmental Engineering, Kyoungwon University;Department of Civil & Environmental Engineering, Kyoungwon University;
  • 중금속 오염배지에서 식물성장증진 근권미생물에 의한 식용 피 발아율과 유식물 성장 증진
  • 이아름;배범한;
  • 경원대학교 토목환경공학과;경원대학교 토목환경공학과;
Abstract
Positive effect of multiple-PGPR (Plan Growth Promoting Rhizobacteria), isolated from heavy metal contaminated soil, on the germination of Barnyard grass (Echinochloa crus-galli var. frumentacea) was quantitatively estimated in 5 heavy metal (Cd, As, Ni, Cu, and Pb) contaminated liquid medium. The $EC_{50}$ value for respective heavy metal was estimated by TSK (Trimmed Speraman-Karber) model based on germination rate. The results showed overall increase in $EC_{50}$ with PGPR inoculation. The $EC_{50}$ value increased 1.4% from 96.0 mg/L (control) to 97.4 mg/L (PGPR-treated) in As contaminated medium. In Ni contaminated medium, the $EC_{50}$ value increased 31.9% from 148.0 mg/L (control) to 195.2 mg/L (PGPR-treated), while the $EC_{50}$ showed 4.8% increase from 63.4 mg/L (control) to 66.5 mg/L (PGPR-treated) in Cu medium. Overall seedling growth was stronger in the PGPR treated seeds than that in the control, but positive effect on seedling growth was not conspicuous. At effective concentration of 100 mg/L, the average seedling length of the PGPR treatment in As, Cd, Cu, and Ni medium, respectively, was 1.13, 0.14, 0.40, and 0.06 cm longer than that in the control. However, the increase of seedling growth was statistically insignificant (p < 0.05). These results suggest that inoculation of the isolated-PGPR exerts positive effects on seed germination by reducing heavy metal toxicity and can be an effective tool for application of phytoremediation on heavy metal contaminated soils.

Keywords: $EC_{50}$;Echinochloa crus-galli var. frumentacea;Heavy metal;Germination;PGPR;

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