氮素形态对铁线莲光合特性及氮代谢的影响

为了解铁线莲的光合性能和氮素代谢的响应机制,对不同氮素形态配比下1 a生厚叶铁线莲(Clematis crassifolia)与天台铁线莲(C.paten ssp.tientaiensis)的生长、光响应曲线、A-Ci曲线和氮代谢相关酶活性进行了比较.结果表明,氮素形态配比显著影响铁线莲的生物量和叶绿素(Chl)含量,...

Effect of Nitrogen Forms on Photosynthetic Characteristics and Nitrogen Metabolism of Clematis

In order to understand the photosynthetic characteristics and response mechanism of nitrogen metabolism in Clematis, the growth, light response curve, A-Ci curve and nitrogen metabolism related enzyme activities of 1-year-old Clematis crassifolia and C. paten ssp. tientaiensis were studied under different ratios of NH₄⁺-N:NO₃^--N. The results showed that the ratio of NH₄⁺-N:NO₃^--N significantly affects the biomass and chlorophyll content of clematis, and the biomass, Chl a, Chl b, and Car contents of C. crassifolia reach the maximum under the ratio at 1:1, while the Chl a and Chl b contents of C. paten ssp. tientaiensis reach the maximum under the ratio at 1:3. Under the ratio of 1:1, the light saturation point (LSP) of C. crassifolia and the light compensation point (LCP) of C. paten ssp. tientaiensis were the maximum, and the V_cmax and J_max values of C. crassifolia leaves were significantly higher than those under other ratios. The glutamine synthetase (GS) activity of C. paten ssp. tientaiensis was the highest under the ratio of 3:1, while NR and nitrite reductase (NiR) activities under the ratio at 1:3 were significantly higher than those under other ratioes. Therefore, the mixed application of NH₄⁺-N and NO₃^--N could effectively promote the growth and photosynthesis, and enhance the nitrogen utilization efficiency of two Clematis. C. crassifolia was suitable for 1:1 of NH₄⁺-N to NO₃^--N, while C. paten ssp. tientaiensis was more suitable for 1:3.