Study On The Effect Of Lambda-cyhalothrin On Quality And Physiological Characteristics In Pakchoi

In this experiment, pakchoi(Siyueman) was used as material to study the effect of Cyhalothrin MEtreatment(1000,500,350,250times dilution, effective concentrations were12.5,25,37.5,50g.ai/hm2) onphysiological characteristics and quality of pakchoi harvested at different intervals (0,2,4,6,8days).Several parameters related with physiological characteristics and quality were tested, such aspesticide residues, the content of MDA, soluble protein and glucosinolates, the activity of superoxidedismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX). This might helpus understand the mechanism of Cyhalothrin5%ME on growth and antioxidant quality in pakchoi. Andthe effect of Cyhalothrin5%ME on Brassica crops were also discussed. The results showed that:(1) The declining rates of Cyhalothrin5%ME in pakchoi were relatively faster in the initial days, thehalf-lives were in the range of2to4days. The biomass in pakchoi increased significantly with1000-fold dilution..The high concentration inhibited the growth of pakchoi, and the higher theconcentration the more obvious inhibition. But, the dry matter content increased significantly with350-fold dilution, increased by5.2%.(2) The SOD, CAT, POD activities were inhibited with high concentrations (350,250-fold dilution), butSOD activity was promoted with low concentrations (1000,500-fold dilution). Cyhalothrin5%ME inhigh concentrations (500,350,250-fold dilution) inhibited glutathione content, but can activate APXactivity in pakchoi. Lambda cyhalothrin could significantly increase the content of vitamin C in pakchoi(P <0.05), and appropriate concentration (1000,500-fold dilution) of Cyhalothrin5%ME has apromoting in soluble protein content. Higher concentrations (350,250-fold dilution) caused a significantincrease in MDA content.(3) The impacts of Cyhalothrin5%ME on secondary metabolites in pakchoi were greater. Thesecondary metabolites content,such as total phenols, flavonoids and glucosinolates with treatment ofhigh concentrations were significantly different from the control. The effects of Cyhalothrin5%ME onpachoi decreased with the degradation of pesticides.