硒对镉胁迫下豆瓣菜生长、生理特性及镉积累的影响

Effects of Se on the growth and Cd accumulation of Nasturtium officinale under Cd stress

通过营养液栽培,研究镉胁迫下不同浓度硒处理对豆瓣菜生长、生理特性及镉含量的影响。结果表明:硒能降低镉胁迫下豆瓣菜丙二醛(MDA)含量和不同部位镉含量,对产量、根系活力、叶绿素含量、净光合速率和抗氧化酶活性等指标具有不同程度的促进作用;随Se浓度的升高,豆瓣菜不同部位硒含量随之升高,当Se^(2+)浓度为3.00和5.00mg·L^(-1)时,豆瓣菜地上部分Cd^(2+)含量分别为0.188和0.176mg·kg^(-1),低于国标安全限值;但Se^(2+)浓度为5.00mg·L^(-1)时,豆瓣菜地上部分Se^(2+)含量达到0.136mg·kg^(-1),超过GB 2762-2012规定的Se^(2+)含量标准。说明硒处理对镉胁迫下豆瓣菜的生长具有较好促进效果,在豆瓣菜出现轻微镉污染时,3.00mg·L^(-1) Se^(2+)处理既能有效降低豆瓣菜地上部镉含量,又可增加豆瓣菜硒含量,获得富硒豆瓣菜。

A hydroponic experiment was carried out to study the effects of Se on the growth and Cd accumulation of watercress under Cd stress. The results showed that Se resulted in the reduction of MDA content and Cd accumulation of watercress, and had positive effects on yield, root activity, chlorophyll content, net photosynthetic rate and antioxidant enzyme activity. Se concentration in different parts of watercress increased with the increasing Se content in nutrient solu- tion. When Se concentration was 3.00 and 5.00 mg · L^- 1, the Cd concentration in edible parts of watercress was 0. 188 and 0. 176 mg· kg^-1respectively, which was under the limit value of national standards. But Se concentration in edible parts of watercress exceeded the limit value, when Se treatment level was 5.00 mg · L^-1. In conclusion, Se has positive effects on the growth of watercress under Cd stress. When watercress was slightly polluted by Cd, 3.00 mg · L^-1 Se can reduce the accumulation of Cd, ensuring the edible safety of Se-enriched watercress.