Abstract：
Fifteen poplar varieties were used in a field trial to investigate the phytoremediation efficiency, stress resistance, and wood property of poplar hybrid varieties with diverse genetic backgrounds under the composite pollution of heavy metals. The coefficient of variation and clone repeatability for growth traits and Cd concentration were large. The Cd accumulation of poplar varieties 107 and QHQ reached 1.9 and 1.7 mg, respectively, followed by QHB, Ti, 69, and Pa, in which Cd accumulation reached 1.3 mg. Most of the intra-specific hybrid varieties (69, QH1, SL4, T3, and ZL46) had low Cd concentrations and small biomass, resulting in weak Cd accumulation and low phytoremediation efficiency for Cd-polluted soil. By contrast, the inter-sectional and inter-specific hybrid varieties exhibited better growth performance and accumulated higher concentrations of heavy metals than the intra-specific hybrids. The bioconcentration factor and translocation factor of Hg, As, and Pb were less than 1, indicating that poplars have low phytoremediation efficiency for these heavy metals. The hybrids between section Aigeiros and Tacamahaca (QHQ and QHB) and the inter-specific hybrid 107 within section Aigeiros were more resistant to composite heavy metal stress than the other poplar varieties were partially because of their high levels of free proline that exceeded 93 μg·g-1 FW. According to the correlation analysis of the concentrations of the different heavy metals, the poplar roots absorbed different heavy metals in a cooperative manner, indicating that elite poplar varieties with superior capacity for accumulating diverse heavy metals can be bred feasibly. Compared with the intra-specific hybrid varieties, the inter-sectional (QHQ and QHB) and inter-specific (107) hybrid varieties had higher pollution remediation efficiency, larger biomass, higher cellulose content, and lower lignin content, which is beneficial for pulpwood. Therefore, breeding and extending inter-sectional (QHQ and QHB) and inter-specific hybrid varieties can improve the phytoremediation of composite pollution.
摘要：
在田间试验中使用了15个杨树品种来研究植物修复效率，抗应力，在重金属复合污染下，具有不同遗传背景的杨树杂交品种的木材特性。生长性状和Cd浓度的变异系数和无性系重复性较大。杨树品种107和QHQ的Cd积累量分别达到1.9和1.7mg,分别,其次是QHB，Ti,69，爸爸，其中Cd积累量达到1.3mg。大多数种内杂交品种（69，QH1，SL4，T3和ZL46）的Cd浓度低，生物量小，导致Cd污染土壤的Cd积累较弱，植物修复效率较低。相比之下,与种内杂种相比，跨区和种间杂种品种表现出更好的生长性能和积累更高的重金属浓度。汞的生物富集因子和易位因子，As,Pb和Pb均小于1，表明杨树对这些重金属的植物修复效率较低。Aigeiros部分和Tacamahaca部分之间的杂种（QHQ和QHB）以及Aigeiros部分内的种间杂种107对复合重金属胁迫的抵抗力比其他杨树品种更高，部分原因是它们的游离脯氨酸含量超过93μg·g-1FW。根据不同重金属浓度的相关性分析,杨树根部以合作的方式吸收不同的重金属，表明积累多种重金属的优良杨树品种是可行的。与种内杂交品种相比，跨系(QHQ和QHB)和种间(107)杂交品种具有较高的污染修复效率,较大的生物量，纤维素含量较高，和较低的木质素含量，这对纸浆木材是有益的。因此,选育和推广跨节杂交(QHQ和QHB)和种间杂交品种可以提高复合污染的植物修复能力。
