鉛、鎘單一及復合污染對11個空心菜品種種子萌發和幼苗生長效應的影響

李富榮　朱娜　楊銳　杜應瓊　王富華

摘 要 以11個品種的空心菜種子為研究對象，研究了不同濃度的鉛、鎘及其復合污染對不同空心菜種子萌發率、幼苗根長、苗高及生物量的影響，比較了不同處理對空心菜種子萌發和幼苗生長抑制效應的品種差異，旨在為重金屬中輕度污染農田土壤栽培空心菜的品種選擇及農產品質量安全保障提供參考。結果發現：鉛、鎘單一或復合污染對幼苗生長比種子萌發的抑制作用更明顯，其中幼苗根生長對鉛鎘污染比種子萌發等指標更為敏感，因此將幼苗根生長作為評價重金屬鉛鎘毒害的指標更為合理。隨著鉛、鎘單一及鉛鎘復合污染濃度的加大，其對空心菜各品種幼苗生長的抑制作用也逐漸增大，且同樣濃度下，鉛鎘復合污染往往比單一重金屬污染的抑制率更高，說明鉛鎘污染存在協同效應。其中，對空心菜各指標的綜合抑制效應在鉛、鎘單一污染下最高達48.78%和42.84%，而在鉛鎘復合污染時最高達59.73%。另外，不同品種對鉛、鎘污染的敏感性不同，通過比較，區分了3個耐鉛鎘污染品種和2個鉛鎘污染敏感品種。

關鍵詞 鉛；鎘；空心菜；復合污染；種子萌發

中國分類號 S181 文獻識別碼 A

Abstract To screen suitable cultivars in heavy metal polluted agricultural soils and reduce the risk of pollutants entering the human diet from soils via agricultural products， the variations in inhibitory effects of simplex / combined Pb and Cd pollution on the seed germination and seedling growth of different Ipanoea aquatica cultivars were studied. The results showed that seedling growth reflected the effects of Pb and Cd pollution on I. aquatica even more than the seed germination. Among them， root growth which was the most sensitive to lead and cadmium pollution could be used as the important index to assess the toxic effect of heavy metal lead and cadmium. As heavy metal pollution concentrations increased， the inhibitory effect of simplex / combined Pb and Cd pollution on seedling growth of I. aquatica was strengthened. Additionally，under the same concentration of some heavy metal element，the combined pollution usually caused higher inhibition rates than the simplex pollution. It was suggested that there was a synergistic effect between lead and cadmium pollution. The maxmium comprehensive inhibitory effects of all parameters under simplex Pb and Cd pollution was 48.78% and 42.84%， respectively， while the maxmium value under combined pollution was 59.73%. Besides， different cultivars showed different sensitivity to lead and cadmium pollution. There were three cultivars to be considered as the tolerant cultivars to lead and cadmium pollution and two cultivars to be sensitive cultivars.

Key words Lead； Cadmium； Ipanoea aquatica； Combined pollution； Seed germination

doi 10.3969/j.issn.1000-2561.2015.11.006

鉛（Pb）和鎘（Cd）是環境中重要的有毒重金屬，其所帶來的環境污染問題和食品安全問題廣受關注。鉛作為對生態環境危害極大的重金屬元素之一，進入土壤后不能被微生物降解，很難去除，對植物和動物都會產生較大的毒害[1-2]。而鎘在土壤中的有效態比例較高，活性較強，很容易被作物吸收而污染食物鏈，危及人類健康[3]。……