土壤高砷污染对冬小麦和油菜生长影响的比较研究

Effects of high arsenic pollution in soil on growth of winter wheat(Triticum aestivum L.) and rape(Brassica napus)

采用盆栽试验研究了土壤高浓度砷污染对冬小麦和油菜生长、生物量、产量的影响及磷、砷在此2种作物各个部位的累积规律。结果表明,200 mg.kg-1土壤砷污染显著抑制了冬小麦的生长,收获时冬小麦株高较对照降低17%;冬小麦地上部分、根系的生物量和产量较对照分别降低了52.2%,60.6%和46.8%。但土壤砷污染对油菜株高、生物量影响均不显著,产量较对照降低了15.4%。砷在冬小麦、油菜各部位的含量为根系>茎叶>颖壳(角果皮)>种子。相同砷污染条件下,小麦根系砷浓度(74.86 mg.kg-1)显著高于油菜根系砷浓度(57.76 mg.kg-1),但地上部分砷含量差异不大,冬小麦籽粒中砷的含量高于油菜籽粒,但均未超过0.7 mg.kg-1。土壤砷污染对冬小麦、油菜根系、茎叶中磷含量影响不大,但显著降低了颖壳(角果皮)中磷的含量。油菜较冬小麦对砷有更高的耐性,砷污染土壤中种植越冬作物时,更适合种植油菜。

A pot experiment was carried out to investigate the effects of high soil arsenic pollution on the growth, biomass accumulation and productivity in winter wheat （Triticum aestivurn L. ） and rape （ Brassica napus ） . The accumulation pattern of phosphorus and arsenic in different parts of plant was also studied in the two species. The results indicated that arsenic significantly inhibited wheat height, root biomass, shoot biomass and yield compared with the control, with reductions of 17% , 52. 2% , 60. 6% and 46.8% , respectively. However, arsenic did not affect the growth and biomass in rape, and the yield was only decreased by 15.4% compared with the control. Arsenic concen- tration in different parts of wheat and rape showed the same pattern ： roots 〉 shoots 〉 husk （]cgumen） 〉 seeds. Arse- nic in roots of wheat and rape were 74. 86 mg· kg^-1 and 57.76 mg·kg^-1 , respectively when soil arsenic concentration was 200 mg·kg^-1. However, there was no difference of arsenic content in the shoot between wheat and rape. Seeds of winter wheat contained more arsenic than rape seed, however, arsenic contents of both seeds did not exceed the maximum levels of contaminants in foods （0. 7 mg·kg^-1 total arsenic）. Arsenic did not significantly affect P concentration of roots and shoots in both wheat and rape, but significantly decreased P concentration of husk or pod peel.Therefore, winter wheat was more sensitive to arsenic compared with rape and it is more suitable for rape growth in arsenic contaminated soil in winter.