氮素不同形态配比对夏枯草苗期生长及光合特性的影响

Influence of nitrogen forms ratio on growth and photosynthetic characteristics in Prunella vulgaris

目的:探讨不同氮素形态对夏枯草生长及光合特性的影响,为夏枯草氮肥的合理施用提供一定依据。方法:采用水培法,测定在等氮水平(15 mmol.L-1)不同铵硝比处理下,夏枯草叶面积、生物量、叶绿素含量及光合相关参数。结果:随着铵硝比的下降,夏枯草叶面积先增加后下降,全铵营养(NH4+-N∶NO3--N为100∶0)下最小,当NH4+-N∶NO3--N为25∶75时最大;随硝态氮比例的提高,夏枯草全株鲜重不断增加,在全硝处理时达到最大,是全铵处理的5.11倍;而全株干重则以NH 4+-N∶NO 3--N为25∶75的最大,且与全硝处理无显著差异。铵硝比为50∶50时叶片中总叶绿素、类胡萝卜素含量最高。铵硝比为25∶75时,夏枯草净光合速率(Pn)最大,全铵处理下最低。结论:在总氮水平为15 mmol.L-1下,适量增加硝态氮比例,有利于促进夏枯草苗期生长、提高干物质积累和净光合速率。

Objective：The effects of different nitrogen forms on the growth and photosynthetic characteristics of Prunella vulgaris were observed.Method：Water culture experiments were carried out to observe the effects of NH＋4∶NO-3 ratios（100∶0,75∶25,50∶50,25∶75,0∶100 in mmol·L-1） on the growth and photosynthetic characteristics of P.vulgaris.Result：The leaf area,fresh biomass and Pn of these cultivars increased with the increasing of NH＋4-N∶NO-3-N ratios,and they were found to be the highest in 25∶75 NH＋4-N∶NO-3-N.However,they decreased with the increasing NH＋4-N∶NO-3-N ratio further.P.vulgaris had a minimum leaf area,biomass,chlorophyll content and Pn in pure ammonium group.The biggest chlorophyll and carotenoid contents were found in the ratios of NH＋4-N to NO-3-N of 50∶50.Conclusion：The results indicated that properly increasing nitrate proportion could promote the growth and photosynthesis of P.vulgaris.