Effects of Root Restriction Treatment on Vegetative Growth and Quality of Spinach

Taking ‘Jinghuzhuye’spinach as the test material, the method of restricting the container volume was adopted and three treatments were set up, with the volumes of T1（90 cm~3）,T2（250 cm~3） and CK（700 cm~3）.The effects of root restriction cultivation with different volumes on the growth, photosynthetic characteristics, physical and chemical properties and quality of spinach were studied, in order to provide reference for the cultivation of high-quality protected vegetables in China.The results showed that compared with CK,the plant height, stem diameter and leaf area of T1 and T2 decreased; the root surface area, volume, root length, number of root tips and dry matter decreased accordingly.However, the root activity of T2 was higher in unit root domain volume, which was 2.4 times and 1.64 times than that of T1 and CK.Compared with CK the net photosynthetic rate of plants reduced by 17.46% and 13.65% in T1 and T2,respectively.For chlorophyll fluorescence, the Fv/Fm value decreased to 0.78 and 0.80 in T1 and T2 treatments and the NPQ showed CK＞T2＞T1.Compared with CK,the contents of available phosphorus, ammonium nitrogen and nitrate nitrogen were significantly increased by 21.27%,32.18% and 53.95% after T2 root restriction treatment.The increase of pH after root restriction alleviated the acidification of the substrate, and the increase of EC was also within the range of normal plant growth.In addition, compared with CK,the contents of soluble sugar and vitamin C in T2 root restriction treatment increased by 2.06 times, 1.43 times respectively.And there was no significant difference between titratable acids.For T1 and T2 treatments, especially T2 treatment（250 cm~3）,more mineral nutrients were accumulated in the root zone, and the content of vitamin C and soluble sugar in spinach was high.