农药CuSO_4处理对空心菜生长及营养品质的影响

The Effects of Pesticide CuSO_4 on the Growth,Nutrition and Quality of Ipomoea aquatic

随着人们对食品安全关注度的增加,具有无公害、不产生抗药性等特点的铜制剂正被大量应用于有机农业生产中.铜制剂的大量施用是否真对食品品质无害值得关注.本文以空心菜的种子和幼苗为材料,分析了CuSO4处理下种子萌发和幼苗生长、品质等的变化.结果显示,≤1mMCuSO4的处理对种子萌发率影响不明显,但会降低种子萌发质量;≤9mMCuSO4的处理对空心菜幼苗的生长、光合、产量和营养含量影响不大;CuSO4处理会增加空心菜体内的铜积累,并将铜优先积累于根部;各处理组空心菜茎叶铜含量不超标,但≥3mMCuSO4处理将会导致根部铜含量超标;CuSO4处理降低了空心菜体内的硝酸还原酶活性,促使硝酸盐在空心菜体内累积,并达到重度污染水平,降低了蔬菜品质,提高了人类的患癌风险.

With the increase of focus on food safety,copper agents which have the characteristics of pollution-free,no resistance etc. are widely used in organic agricultural production. Whether the extensive application of copper agents will bring influence on the yield and quality of foods or not is noteworthy. To inspect this influence,the changes of seed germination,seedling growth and vegetable quality of Ipomoea aquatic under CuSO4 processing will be assayed in this paper.Results showed that Cu SO4 treatment not over 1 m M had no obvious effect on seed germination rate,but would reduce seed germination quality. CuSO4 treatment not over 9 m M had no obvious effect on seedling growth,photosynthesis,yield and nutrient content. CuSO4 treatment would increase copper accumulation in I. aquatic seedlings,and copper would accumulate preferentially in roots. Copper content in leaves and stems in the treated I. aquatic seedlings would not exceed the national standard,but it would exceed the standard in roots when CuSO4 was not less than 3 mM. CuSO4 treatment would reduce the nitrate reductase activities which led to the nitrate accumulation to the severe pollution level in I. aquatic seedlings. This would reduce the vegetable quality and enhance the human cancer risk.