Studies On Effects Of Quinhydrone Upon Vegetable Growth And Its Mechanism

Effects of quinhydrone, as urease inhibitor, on growth, root activities, nitrogen metabolism, photosynthetic character, yield as well as quality were studied under pot experiment with water spanich and plot experiment with B.chinensis Var.comrtzunis. The results were shown as follow: 1. Applying low and medium amount quinhydrone promoted the growth of water spanich and B.chinensis Va,communis, whereas high amount treatment had little effect on water spanich growth, and inhibited the growth of B.chinensis Var communis. 2. Applying quinhydrone, the activities of root and root Na+-K+-ATPase improved, the root respiration rate increased, and their increment of medium amount quinhydrone are the highest compared to other treatments. 3. The activities of nitrate reductase(NR), glutamate dehydrogenase(GDH) and glutamine synthetase(GS) in water spanich leaves were enhanced, the contents of total nitrogen and protein increased, but the content of free amino acid decreased. Compared to the control, low and medium amount of quinhydrone made significant difference respectively, but high amount had not notable effects. 4. Leaf chlorophyll and water spanich chlorophyll fluorescence parameters(Fv, Fv/FO, Fv/Fm, Rfd) increased, and the increments of low and medium amount treatment are significant. Also, applying low and medium amount quinhydrone, Pn increased in B.chinensis Var.communis, while En, Cs and Ci reduced, otherwise the high amount treatment had opposite effects. 5. Proper amount quinhydrone markedly increased the yields and improved the qualities of the two vegetables.