摘要
施用外源硅肥对很多禾本科植物生长有积极作用,但对豆科植物缺磷的缓解作用和机制研究较少。本研究以豆科牧草紫花苜蓿(Medicago sativa L.)为对象进行盆栽试验,设置2个营养处理,即营养均衡和磷限制,以及3个硅酸钾(K_(2)SiO_(3))添加浓度,即0 mmol/L、1 mmol/L、2 mmol/L,旨在研究硅添加对磷限制下紫花苜蓿生长特征、光合特性以及氮、磷元素吸收和化学计量特征(N∶P)的影响。结果表明:相对于营养均衡条件,磷限制显著降低了苜蓿生物量、株高、光合速率、气孔导度、蒸腾速率、光合水分利用效率和地上部磷含量,提高了地上部N∶P,尤其在不添加硅的情况下;添加硅显著提高了磷限制时植物生物量、株高、光合速率、气孔导度、蒸腾速率和地上部磷含量,但营养均衡条件下添加硅降低了气孔导度,对其他指标无显著影响。相关性分析表明,磷限制条件下,紫花苜蓿地上部硅含量与磷含量呈显著正相关,与N∶P呈显著负相关,而在营养均衡条件下,相关性不显著。因此,硅添加在一定程度上缓解了豆科植物紫花苜蓿的磷限制,并揭示了通过化学计量学调节体内营养使其趋向内稳态的相关机制,在土壤磷素缺乏的背景下为硅在紫花苜蓿栽培利用提供科学指导和理论依据。
While the beneficial effects of silicon addition on Poaceae species have been widely reported,its mitigating effects and mechanisms of phosphorus deficiency in legumes remain unclear.In this study,a pot experiment was designed to investigate the effects of silicon application on alfalfa(Medicago sativa L.)under phosphorus limitation.Two nutrient conditions(nutrient balance and phosphorus limitation)and three concentrations of potassium silicate(0,1,and 2 mmol/L)were applied to determine the effects of silicon addition on the growth characteristics,photosynthetic parameters,and nitrogen and phosphorus stoichiometric traits of the alfalfa under phosphorus limitation.The results showed that alfalfa biomass,plant height,photosynthetic rate,stomatal conductance,transpiration rate,photosynthetic water use efficiency,and shoot phosphorus content were significantly reduced by phosphorus limitation,whereas the shoot N∶P ratio increased particularly when no silicon was added.Silicon addition significantly increased biomass,plant height,photosynthetic rate,stomatal conductance,transpiration rate,and shoot phosphorus content of alfalfa under phosphorus limitation,while the addition under nutrient-balanced condition reduced stomatal conductance without affecting other parameters.Correlation analysis further revealed that under phosphorus-limited conditions,shoot silicon content was positively correlated with shoot phosphorus content and negatively correlated with the N∶P ratio.However,these correlations were not observed under nutrient-balanced conditions.Therefore,phosphorus limitation of alfalfa can be mitigated by silicon addition.Results demonstrated the associated mechanisms driving internal nutrient homeostasis from a stoichiometric perspective,and provided guidance and theoretical basis for the utilization of silicon in alfalfa cultivation under phosphorus deficiency.
作者
李俊霖
宋婵
钱程
赵欣
胡雅飞
刘大林
王琳
李新娥
LI Junlin;SONG Chan;QIAN Cheng;ZHAO Xin;HU Yafei;LIU Dalin;WANG Lin;LI Xine(College of Animal Science and Technology,Yangzhou University,Yangzhou 225009,China;Institutes of Agricultural Science and Technology Development(Joint International Research Laboratory of Agriculture&Agri-Product Safety),Yangzhou University,Yangzhou 225009,China)
出处
《中国草地学报》
北大核心
2025年第5期1-11,共11页
Chinese Journal of Grassland
基金
2023江苏省研究生实践创新计划项目(SJCX23_1989)。
关键词
磷限制
紫花苜蓿
硅添加
氮磷比
Phosphorus limitation
Alfalfa
Silicon addition
N∶P ratio
