摘要
【目的】适宜的Na^(+)与Cl^(-)浓度均有利于植物的生长,但Na^(+)和Cl^(-)哪个起主导作用,以及二者之间的平衡关系对其有益作用的影响尚不清楚。因此,拟通过本研究为低浓度氯化钠在生产中的应用提供理论依据。【方法】采用盆栽试验培养小白菜(Brassica campestris L.ssp.chinensis var.communis Tsen et Lee),在小白菜长到3叶1心时进行叶面喷施处理。以NaCl为基础,设置了[Na^(+)]<[Cl^(-)](A)、[Na^(+)]=[Cl^(-)](B)和[Na^(+)]>[Cl^(-)](C)3组处理。B组平衡态的3个处理的[Na^(+)]∶[Cl^(-)]的浓度(mmol/L)比为6∶6(B_(1))、12∶12(B_(2))、18∶18(B_(3));A组非平衡态的3个处理为0∶6(A1)、6∶12(A2)、12∶18(A3);C组非平衡态的3个处理的比值是6∶0(C_(1))、12∶6(C_(2))、18∶12(C_(3)),以无离子水为对照CK,每日喷施一次,连续处理21天。停止喷施后,取样观测叶片组织结构,测定植株干鲜物质量、叶片光合活性以及游离氨基酸含量。【结果】无论[Na^(+)]和[Cl^(-)]是平衡还是非平衡状态,喷施处理均显著提高了小白菜的干鲜物质积累量和叶片光合活性。与CK相比,3个[Na^(+)]、[Cl^(-)]等浓度供给处理均显著增加了小白菜植株干、鲜生物量,显著增加了植株游离氨基酸含量,增加了叶面积尤其是中上位叶面积,促生效果均以B_(2)处理最佳,植株干、鲜生物量分别比CK增加了35.1%和43.7%,叶面积增加了33.4%。在非平衡状态中,有Cl^(-)无Na^(+)时有利于含水量增加,有Na^(+)无Cl^(-)时有利于干物质累积,且表现出Na^(+)和Cl^(-)均有利于含水量增加,Na^(+)比Cl^(-)更有利于游离氨基酸累积([Na^(+)]>[Cl^(-)]时,增加52.6%),Cl^(-)比Na^(+)更有利于干物质累积和光合速率([Na^(+)]<[Cl^(-)]时,增加17.3%)以及气孔导度([Na^(+)]<[Cl^(-)]时,增加145.3%)增加的现象。2因素主体间效应检验显示,小白菜的植株干鲜物质和营养物质累积、叶面积和比叶重、叶片光合气体交换活性,既受Na^(+)、Cl^(-)单独离子效应的影响,又受Na^(+)与Cl^(-)交互效应的影响。【结论】叶面喷施[Na^(+)]与[Cl^(-)]平衡与否都对小白菜的生长、干物质累积、含水量增加和叶片光合活性具有促进效应。但以12 mmol/L NaCl的生长促进效应更优,其主要表现为叶面积的扩展促使植株干物质累积。
【Objectives】The optimum concentration of Na^(+)or Cl^(-)is beneficial to plant growth.Yet,it is unclear which one plays a dominant role and how the balanced relationship between the elements presents better beneficial effects.Therefore,this study was conducted to provide a reference for applying a low concentration of sodium chloride in leafy vegetable production.【Methods】The seeds of pakchoi(Brassica campestris L.ssp.chinensis var.communis Tsen et Lee)were planted in a pot filled with a soilless matrix.Foliar application of Na^(+)and Cl^(-)was consecutively carried out at the 3-true-leaves stage.The treatments were composed of three groups and three levels of[Na^(+)]and[Cl^(-)].The different groups were[Na^(+)]=[Cl^(-)](B),with[Na^(+)]and[Cl^(-)]at 6 mmol/L(B_(1)),12 mmol/L(B_(2)),and 18 mmol/L(B_(3)).The second group had[Na^(+)]<[Cl^(-)](A),[Na^(+)]∶[Cl^(-)]at 0∶6 mmol/L(A1),6∶12 mmol/L(A2),and 12∶18 mmol/L(A3).The third group had[Na^(+)]>[Cl^(-)](C),with[Na^(+)]∶[Cl^(-)]at 6∶0(C_(1)),12∶6 mmol/L(C_(2)),and 18∶12 mmol/L(C_(3)),respectively.We sprayed deionized water simultaneously as control(CK).The leafy tissue structure was observed.The fresh and dry biomass,leaf photosynthetic activity,and free amino acid content were measured immediately after spraying.【Results】Compared with CK,all the[Na^(+)]and[Cl^(-)]treatments(P<0.05)increased the fresh and dry biomass and leaf photosynthetic activity of pakchoi.The[Na^(+)]=[Cl^(-)]group also increased the free amino acid content and leaf area,especially the middle and upper leaves.The highest dry and fresh biomass and leaf area were recorded in B_(2),which were increased by 35.1%,43.7%,and 33.4%,respectively.Cl^(-)favored water accumulation in the absence of Na^(+),while Na^(+)favored dry biomass accumulation in the absence of Cl^(-).Both elements(Na^(+)and Cl^(-))favored water accumulation.Na^(+)was more conducive to the accumulation of free amino acids than Cl^(-)(i.e.[Na^(+)]>[Cl^(-)],52.6%increase),Cl^(-)was more conducive to the accumulation of dry biomass and photosynthetic rate(i.e.[Na^(+)]<[Cl^(-)],17.3%increase)and stomatal conductance(i.e.[Na^(+)]<[Cl^(-)],145.3%increase)than Na^(+).A 2-factor intersubjective effect test showed both Na^(+)and Cl^(-)(P<0.05)affect the dry biomass,fresh weight,nutrients content,leaf area,specific leaf weight,and leaf gas exchange of pakchoi at the main and interaction levels.【Conclusions】Foliar spraying of Na^(+)and Cl^(-)could promote the growth,dry biomass accumulation,and leaf photosynthetic activity of pakchoi.Supplying[Na^(+)]and[Cl^(-)]in equal concentration had a higher effect than unequal supply,and the optimum spraying concentration was NaCl 12 mmol/L.
作者
张维霞
高爽
王俊玲
陈倩倩
薛占军
高志奎
ZHANG Wei-xia;GAO Shuang;WANG Jun-ling;CHEN Qian-qian;XUE Zhan-jun;GAO Zhi-kui(College of Horticulture,Agricultural University of Hebei,Baoding,Hebei 071001,China;College of Food Science and Technology,Agricultural University of Hebei,Baoding,Hebei 071001,China;College of Life Sciences,Agricultural University of Hebei,Baoding,Hebei 071001,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2022年第5期906-918,共13页
Journal of Plant Nutrition and Fertilizers
基金
河北省重点研发计划项目(18226928D)。
