不同形态氮素配施对娃娃菜光合和叶绿素荧光特性的影响

Effects of different nitrogen forms and ratios on photosynthetic characteristics of Brassica pekinensis

通过大田试验分析不同氮素形态及配比下娃娃菜叶绿素荧光动力学参数和光合气体交换参数的变化规律,以及光合特性与硝态氮和铵态氮配比之间的相关性关系。结果表明,不同氮素形态及配比处理下娃娃菜叶片在苗期、莲座期、结球期的叶绿素a、叶绿素b、叶绿素a+b和类胡萝卜素的含量均大于空白对照(CK1),并且各处理间存在较大差异,尤其表现在莲座期和结球期,硝铵比在7∶3和5∶5处理时娃娃菜叶片叶绿素含量较高,有利于叶绿素的积累;在硝铵比为7∶3和5∶5处理及当地施肥(CK2)处理下有利于光能的吸收和传递;二次多项式曲线回归分析说明了硝铵比与实际光化学效率(ФPSⅡ)、净光合速率(Pn)之间的相关性关系,硝铵比在7∶3和5∶5处理时更有利于娃娃菜光能转化和CO2的固定。

The objective of this experiment was to investigate the effects of different nitrogen forms and ratios on photosynthetic characteristics of Brassica pekinensis, and the correlation between photosynthetic characteristics and nitrate ammonium ratios were analyzed. The results showed that chlorophyll a, chlorophyll b, chlorophyll a ＋ b and carotenoid content of Brassica pekinensis were higher than the control （ CK1 ） in different treatments and growth stages, and there were large significance among different treatments especially in the rosette stage and cabbage stage. The chlorophyll contents in the treatment with nitrate ammonium ratios of 7：3 and 5：5 were higher than others, which were beneficial for the accumulation of chlorophyll. Moreover, the treatment with nitrate ammonium ratios of 7：3 and 5：5 and CK2（ local fertilization treatment） were conducive to the absorption, transmission and conversion of light energy. It could be concluded by quadratic polynomial curve regression that there were dependency relationships between ammonium nitrate ratios and the actual photochemical efficiency （ ΦPSⅡ） or net photosynthetic rate （Pn）. When the ammonium nitrate ratios were 7：3 and 5： 5, it were more beneficial for light energy conversion and CO2 fixation in Brassica pekinensis.