Zhou X.-J.,Huaibei Normal University |
Zhou X.-J.,Anhui Province Key Laboratory of Plant Resources and Biology |
Wang H.-H.,Huaibei Normal University |
Wang H.-H.,Anhui Province Key Laboratory of Plant Resources and Biology |
And 9 more authors.
Chinese Journal of Applied Ecology | Year: 2010
A split root system consisting of two compartments was installed to study the effects of nitrogen form and its supply position on the growth of maize seedlings under partial root-zone water stress. Polyethylene glycol (PEG 6000) was added to the nutrient solution in one compartment to simulate partial root-zone water stress, while nitrogen was set as three forms ( nitrate nitrogen, ammonium nitrogen, and their 1 : 1 mixture) and supplied to just one compartment (water-stressed or non-water-stressed compartment). Photosynthetic and other physiological indices were examined. Comparing with the nitrogen supplied to water-stressed compartment, the nitrogen supplied to non-water-stressed compartment improved the photosynthetic rate ( P n) , maximum net photosynthetic rate (P max) , light saturation point (LSP) , CO 2 saturation point (CSP) , chlorophyll content, root activity, nitrogen uptake, and biomass accumulation, but reduced the photorespiration rate (R p) , CO 2 compensation point ( CCP) , abscisic acid ( ABA) concentration in xylem sap, and nitrogen-and water use efficiency of the plants. Supplying nitrate nitrogen or its mixture with ammonium nitrogen improved the P n, P max, LSP, CSP, nitrogen uptake, and biomass accumulation, but reduced the CCP, R p , ABA concentration in xylem sap, and nitrogen- and water use efficiency of the plants, compared with supplying ammonium nitrogen. All the results showed that supplying same nitrogen forms to non-water-stressed compartment wras more beneficial to the plant growth but disadvantageous to the plant nitrogen- and water use, compared with supplying the nitrogen forms to water-stressed compartment, and supplying nitrate nitrogen or its mixture with ammonium nitrogen promoted the plant growth but reduced the plant nitrogen- and water use, compared with supplying ammonium nitrogen.