重金属镉在番茄及其害虫西花蓟马中的积累与传递

重金属镉（Cd）是农田土壤中的重要污染源，可在植物和植食性昆虫中积累与传递。本文采用水培法，研究了不同浓度的Cd在番茄Solanum lycopersicum不同组织和在其重要害虫西花蓟马Frankliniella occidentalis体内的积累量。结果表明，随着水培营养液中Cd浓度的增加，番茄植株的根、茎和叶中Cd含量呈增长趋势。根中Cd的积累量远高于茎和叶，当水培溶液中Cd含量为20 mg/L时，根、茎和叶中的积累量分别达19 333.67±233.38、122.67±6.84和147.33±2.96 mg/Kg（干重）。随着Cd浓度的增加，番茄根、茎和叶的鲜重和干重均显著下降。西花蓟马取食Cd处理的番茄叶片后，体内Cd显著积累，最高达1.95±0.36 mg/Kg。同时，Cd积累量的提高进一步影响了以番茄叶片为食的西花蓟马的适合度，降低了其存活率。除对照外，番茄茎-叶的转移系数和叶片对Cd的富集系数均大于1，叶片表现出较强的富集能力。而在所有的试验浓度处理中，西花蓟马对Cd的富集系数和转移系数均小于1，表明Cd未在其体内产生生物放大作用。研究结果明确了Cd在番茄各组织及其害虫中的积累和传递水平，为揭示重金属在农业生态系统食物链中的富集效应提供了基础数据。

Accumulation and transfer of cadmium in tomato and its pest Frankliniella occidentalis

Heavy metal cadmium (Cd) is one of the major contaminants in farmlands, and it could accumulate and transfer in plants and herbivores. The accumulation of Cd in different tissues of tomato and its important pest western flower thrips Frankliniella occidentalis were tested using hydroponics with different Cd concentrations in this study. The results showed that Cd contents in roots, stems and leaves of tomato seedlings increased with the increase of the Cd concentration in hydroponic solutions. The accumulation of Cd in roots was much higher than that in stems and leaves. When the concentration of Cd in hydroponics solution was 20 mg/L, the accumulation amount of Cd in roots, stems and leaves reached up to 19 333.67±233.38, 122.67±6.84 and 147.33±2.96 mg/Kg dry weight, respectively. At the same time, with the increase of Cd concentration in hydroponic solutions, fresh weight and dry weight of tomato roots, stems and leaves decreased significantly. After feeding on tomato leaves treated with Cd, F. occidentalis accumulated significant amount of Cd with up to 1.95±0.36 mg/Kg. Meanwhile, the concentration increase of Cd treatment further affected the fitness of F. occidentalis feeding on tomato leaves and reduced their survival rates. Except for CK, bio-accumulation factor of tomato leaves and transfer coefficients of stems to leaves were greater than 1, indicating that leaves had strong enrichment ability. Bio-accumulation factor of F. occidentalis and transfer coefficients of leaves to F. occidentalis were less than 1, showing that Cd did not have bio-magnification effects in thrips from the treatment concentrations in this work. This study clarified the accumulation and transfer levels of Cd in tomato tissues and pests, and provided basic data for revealing the enrichment effect of heavy metals in agricultural ecosystem and food chain.