摘要
为给雷竹林的合理施用氮肥提供科学依据,通过盆栽试验,设置了硝铵比(NO_3^--N∶NH_4^+-N)为1∶0、2∶1、1∶1、1∶2、0∶1的5个氮素形态营养处理,测定了雷竹叶片叶绿素a(Chla)、叶绿素b(Chlb)、类胡萝卜素(Car)含量和净光合速率(Pn)、气孔导度(Gs)、胞间CO_2浓度(Ci)、蒸腾速率(Tr)光合参数以及硝酸还原酶(NR)、谷氨酰胺合成酶(GS)活性。结果表明:随氮素供应中NH_4^+-N比例的增加,雷竹叶片Chla、Chlb、Car含量和Pn、Gs、Tr均呈先升高后降低的变化趋势,硝铵比1∶2处理明显高于其他处理,而Ci出现相反的变化规律,在硝铵比1∶2处理时明显低于其他处理;NR、GS活性随NH_4^+-N比例的增加也呈先升高后降低的变化趋势,且NH_4^+-N/NO_3^--N混合营养的处理间无显著差异,均高于单一氮素形态的营养处理。综合分析认为,雷竹为弱喜铵植物,但硝铵混合营养更能促进雷竹光合作用和氮同化能力。
In order to provide scientific guidance for nitrogen fertilization in Phyllostachys violascens stands, a pot experiment was carried out with five ratios of NO3^--N∶NH4^＋-N at 1∶0, 2∶1, 1∶1, 1∶2 and 0∶1. Measured indicators included chlorophyll a （Chla）, chlorophyll b （Chlb） and carotenoids （Car） contents, net photosynthetic rate （Pn）, stomatal conductance （Gs）, intercellular CO2 concentration （Ci）, transpiration rate （Tr）, and activities of nitrate reductase （NR） and glutamine synthetase （GS） in leaves of Phyllostachys violascens. Results showed that, with increasing NH4^＋-N proportion in nitrogen supply, the photosynthetic pigment contents, Gs, Ci and Tr rose at first and then fell. These variables under the treatment of ammonium/nitrate ratio at 1∶2 were significantly higher than those under the other treatments, while Ci variation was opposite. With increasing the proportion of NH4^＋-N, the activities of NR and GS showed a trend of increase at first and then decrease, being not significantly different among the mixed nutrition treatment, but higher in the mixed nutrition treatments than in the single nitrogen treatments. Overall, it might be concluded that P. violascensis a kind of plant that slightly prefers ammonium, and that mixture of ammonium and nitrate can facilitate leaf photosynthesis and nitrogen assimilation.
出处
《生态学杂志》
CAS
CSCD
北大核心
2016年第9期2355-2360,共6页
Chinese Journal of Ecology
基金
浙江省中国林业科学研究院省院合作项目(2013SY04)
中央级公益性科研院所基本科研业务费专项资金项目(RISF61258)资助
关键词
硝态氮
铵态氮
光合参数
硝酸还原酶
谷氨酰胺合成酶
nitrate nitrogen
ammonium nitrogen
photosynthetic character
nitrate reductase
glutamine synthetase
