Effects of DA-6 on growth and physiological characteristics in hydroponic lettuce
DA-6 is a broad-spectrum and high-efficiency plant growth regulator,which has high biological activity and low toxicity. Effects of five DA-6 concentrations(0,20,100,500,1000μg·L-1)on lettuce growth and physiological characteristics were investigated by hydro-ponic approach with the Yamasaki lettuce nutrient solution. The results showed that the lettuce biomass and root items firstly raised and then decreased with the increase of DA-6 concentrations. 100μg·L-1 DA-6 treatment improved the root activity and significantly increased the dry and fresh mass of both shoot and root compared with other treatments,which reached 33.58%~742.86%,11.56%~286.79%,18.60%~264.29% and 11.12%~267.83%,respectively. 1000 μg·L-1 DA-6 treatment reduced the lettuce biomass and root activity in comparison with 0μg·L-1 DA-6 treatment. Different DA-6 concentrations individually impacted on the lettuce qualities. With the increasement of DA-6 concentrations,the nitrate content decreased after the first raise,but the adverse trend of ascorbic acid,soluble sugar and soluble protein contents were observed. 100 μg·L-1 DA-6 treatment significantly reduced the nitrate content by 23.40%than 0 μg·L-1 DA-6 treatment.Whereas,the ascorbic acid,soluble sugar and soluble protein contents of lettuce leaves with 100 μg·L-1 DA-6 treatment significantly in-creased by 24.24%,64.29%and 22.92%compared with 0μg·L-1 DA-6 treatment,respectively. Meanwhile,100μg·L-1 DA-6 treatment increased the SOD,POD and CAT activities,reduced the MDA content,raised the SPAD value,and improved the photosynthesis and chloro-phyll fluorescence properties of lettuce leaves. Under the current experimental conditions,the hydroponic lettuce nutrient solution added in 100μg·L-1 DA-6 was recommended,which not only warranted the high hydroponic lettuce yield but also improved the quality.
国家科技期刊平台
NSTL
万方数据
维普
