不同钾钠水平对甜菜幼苗生理特性的影响

Potassium and Sodium Levels and Sugar Beet Seedlings: Effects on Physiological Characteristics

旨在为钾钠元素在甜菜生产中的合理施用提供理论依据。以甜菜品种‘ST13092’为材料,在水培条件下设置3个K^+水平(0.03、1.5和3 mmol/L)和3个Na^+水平(0、1.5和3 mmol/L),同时K^+和Na^+相互作用,共9个处理。培养3周后测定不同钾钠水平对甜菜幼苗叶片干重、叶面积、水势、相对含水量、叶绿素含量、光合特性、Na^+和K^+含量、N、P、有机酸含量的影响。增加K^+供应水平和Na^+供应水平,甜菜幼苗叶片的干重、叶面积、水势、相对含水量、蒸腾速率、气孔导度、净光合速率、胞间CO2浓度均显著增加,而叶绿素a、叶绿素b、N、P及有机酸含量降低;在K^+和Na^+均为3 mmol/L时,甜菜幼苗叶片的水势、相对含水量、蒸腾速率、气孔导度、净光合速率、胞间CO2浓度以及Na^+和K^+含量达到最大,叶绿素a、叶绿素b含量以及N、P含量达到最小。钾、钠及其交互作用不仅直接增加叶片的叶片水势和叶面积、促进光合作用,还可以增加钾钠离子的渗透调节作用,减少了有机渗透调节的作用,进而间接提高光合产物的利用率,促进幼苗生长,调节植株N、P含量。

The aim is to provide a theoretical basis for the rational application of potassium and sodium in sugar beet production.Using sugar beet variety‘ST13092’as material,three K^+ levels(0.03,1.5 and 3 mmol/L)and three Na+levels(0,1.5 and 3 mmol/L)were set under hydroponic condition.At the same time,K^+ and Na^+ interacted for a total of 9 treatments.After 3 weeks of culture,the effects of different potassium and sodium levels on water potential,relative water content,chlorophyll content,photosynthetic characteristics,Na^+ and K^+ content,N,P and organic acid content of sugar beet seedlings were determined.The dry weight,leaf area,water potential,relative water content,transpiration rate,stomatal conductance,net photosynthetic rate and intercellular CO2 concentration of sugar beet seedlings increased significantly with the increase of K^+ supply level and Na^+ supply level,while the contents of chlorophyll a,chlorophyll b,N,P and organic acids decreased.When both K^+ and Na^+ were 3 mmol/L,the water potential,relative water content,transpiration rate,stomatal conductance,net photosynthetic rate,intercellular CO2 concentration,Na^+ and K^+ contents reached the maximum,and chlorophyll a and chlorophyll b contents,N,P contents reached the minimum.Potassium,sodium and their interactions not only directly increase the water potential and leaf area of leaves,promote photosynthesis,but also increase the osmotic regulation of potassium and sodium ions,reduce the role of organic osmotic regulation,and indirectly improve the utilization rate of photosynthetic products,promote the growth of seedlings,and regulate the content of N and P in plants.