Zhang Na, Zhang Jinwei, Li Zhiqiang, Chen Jing, Zhang Zhenhua, Mu Chunsheng
Institute of Agricultural Resource and Environment, Jiangsu Academy of Agricultural Sciences, Nanjing, China.
Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province, Huaiyin Institute of Technology, Huaian, China.
PeerJ. 2018 Jan 3;6:e4188. doi: 10.7717/peerj.4188. eCollection 2018.
Resistance strategies of clonal organs, and parent and offspring shoots of (common reed) to heavy metal pollution in soils are not well known. To clarify the tolerance or resistance strategies in reeds, we conducted a pot experiment with five levels of Pb concentration (0∼4,500 mg kg) in flood and drought conditions. Lead toxicity had no inhibitory effect on the number of offspring shoots in flood environment; however, biomass accumulation, and photosynthetic and clonal growth parameters were inhibited in both water environment. At each treatment of Pb concentration, offspring shoots had greater biomass and higher photosynthesis indicators than parent shoots. The lowest Pb allocation was found in rhizomes. More of the Pb transported to above-ground parts tended to accumulate in parent shoots rather than in offspring shoots. Biomass and photosynthesis of offspring shoots, rhizome length, and the number of buds, rhizomes and offspring shoots in the flooded treatment were significantly greater than those in the drought treatment. Our results indicated that the tolerance strategies used by reeds, including higher biomass accumulation and photosynthesis in offspring shoots, low allocation of Pb in rhizomes and offspring shoots, and stable clonal growth, maintained the stability of population propagation and productivity, improving the resistance of reeds to Pb pollution in flood environment. However, the resistance or tolerance was significantly reduced by the synergistic effect of Pb and drought, which significantly inhibited biomass accumulation, photosynthesis, and clonal growth of reeds.
克隆器官以及芦苇（Phragmites australis）亲株与子株对土壤重金属污染的抗性策略尚不清楚。为阐明芦苇的耐受或抗性策略，我们在淹水和干旱条件下进行了一项盆栽试验，设置了五个铅浓度水平（0∼4500 mg/kg）。铅毒性对淹水环境中子株数量没有抑制作用；然而，在两种水环境中，生物量积累、光合和克隆生长参数均受到抑制。在每个铅浓度处理下，子株的生物量和光合作用指标均高于亲株。根茎中的铅分配最低。向地上部分运输的铅更多地倾向于在亲株中积累，而非子株。淹水处理下子株的生物量和光合作用、根茎长度以及芽、根茎和子株的数量均显著高于干旱处理。我们的结果表明，芦苇所采用的耐受策略，包括子株中更高的生物量积累和光合作用、根茎和子株中铅的低分配以及稳定的克隆生长，维持了种群繁殖和生产力的稳定性，提高了芦苇在淹水环境中对铅污染的抗性。然而，铅与干旱的协同效应显著降低了抗性或耐受性，这显著抑制了芦苇的生物量积累、光合作用和克隆生长。
