Lead tolerance and accumulation of different tall fescue genotypes

Tall fescue(Festuca arundinacea)is a promising species for remediation of lead (Pb) contaminated soils by phytoextraction. In order to select the genotypes with higher Pb tolerance or high accumulation ability, the growth response, Pb uptake and translocation characteristics of 18 tall fescue genotypes were studied under hydroponic culture with 500, 1 000, 1 500 mg·L-1 of Pb. The results indicated that all of the tested tall fescue genotypes were tolerant to 500 mg·L-1 of Pb. When the Pb concentrations were 1 000 and 1 500 mg·L-1, there were significant variation in turf quality, Pb uptake and translocation among genotypes (P＜0.05). Shoot Pb concentrations in ‘Kentucky-31’,‘PI232876’, ‘PI634229’ and ‘AST7001’ were more than 35 mg·g-1 DW (dry weight). Meanwhile, the translocation factors of these 4 genotypes were higher than others (0.42). Among all the genotypes, ‘Silverado’ had the least shoot Pb concentration (3.34 mg·g-1 DW) and translocation factor (0.03). However it was the most tolerant to high Pb concentration and grew normally in nutrient solution containing 1500 mg·L-1 Pb without suffering phytotoxicity. This work provided new plant genotypes for revegetation or phytoremediation of Pb contaminated soils.