不同钠钾配比对番茄幼苗生长及生理代谢的影响

Effects of Different Sodium and Potassium Proportions on Tomato Seedling Growth and Physiological Metabolism

选用‘中杂9号’番茄品种,采用水培法,以K^(+)浓度(4 mmol/L)为对照,以不同浓度Na^(+)(1、2、3、3.5、3.75、4 mmol/L)与K^(+)(3、2、1、0.5、0.25、0 mmol/L)配施,探究不同钠钾配比对番茄幼苗生长及生理代谢的影响。结果表明:与T1处理(4 mmol/L KNO_(3)+0 mmol/L NaNO_(3))相比,T3处理(2 mmol/L KNO_(3)+2 mmol/L NaNO_(3))对番茄幼苗长势的促进作用最显著,株高、茎粗、整株鲜质量和干质量分别增加28.94%、16.54%、59.14%和44.96%。随着Na^(+)比例增加,番茄根系形态指标和叶片叶绿素含量均呈下降趋势,膜脂过氧化程度加剧,与对照相比,T7处理(0 mmol/L KNO_(3)+4 mmol/L NaNO_(3))下相对电导率和过氧化氢含量的增幅最显著。与对照相比,T2处理(3 mmol/L KNO_(3)+1 mmol/L NaNO_(3))和T4处理(1 mmol/L KNO_(3)+3 mmol/L NaNO_(3))叶片超氧化物歧化酶(SOD)活性分别显著降低,T4、T6(0.25 mmol/L KNO_(3)+3.75 mmol/L NaNO_(3))和T7处理根系SOD活性分别显著增加;叶片过氧化物酶(POD)活性T6处理的降幅最显著,而根系POD活性T7处理增幅最显著;叶片和根系过氧化氢酶(CAT)均呈不同程度增加。Na^(+)比例增大可诱导番茄叶片和根系不同程度地积累渗透调节物质,与对照相比,T7处理脯氨酸含量的变化最显著。隶属函数法综合评价表明,T3处理番茄幼苗各指标均优于其他处理。综上,适宜的钠钾配比可通过调节番茄不同器官的抗氧化防御能力和渗透调节能力来影响其生长发育,且K^(+)和Na^(+)的配比为1∶1时,番茄幼苗的整体长势较佳。

In this experiment,tomato variety‘Zhongza No.9’was selected as experiment variety,the hydroponics was applied,K^(+)concentration(4 mmol/L)was used as the control.The experiment used different concentrations of Na^(+)(1,2,3,3.5,3.75,4 mmol/L)and K^(+)(3,2,1,0.5,0.25,0 mmol/L)to explore the effects of different sodium-potassium ratios on the growth and physiological metabolism of tomato seedlings.The results showed that compared with T1 treatment(4 mmol/L KNO_(3)+0 mmol/L NaNO_(3)),T3 treatment(2 mmol/L KNO_(3)+2 mmol/L NaNO_(3))had the most significant effect on the growth of tomato seedlings.Plant height,stem thickness,fresh mass of whole plant and dry mass of whole plant increased by 28.94%,16.54%,59.14%and 44.96%,respectively.With the increase of the proportion of Na^(+),the root morphological indexes and leaf chlorophyll content of tomato showed a decreasing trend,and the degree of membrane lipid peroxidation increased.Compared with the control,T7 treatment(0 mmol/L KNO_(3)+4 mmol/L NaNO_(3))showed the most significant increase in relative conductivity and hydrogen peroxide content.Compared with the control,T2 treatment(3 mmol/L KNO_(3)+1 mmol/L NaNO_(3))and T4 treatment(1 mmol/L KNO_(3)+3 mmol/L NaNO_(3))reduced leaf superoxide dismutase(SOD)activity.The SOD activity in roots under T4,T6(0.25 mmol/L KNO_(3)+3.75 mmol/L NaNO_(3))and T7 treatments increased significantly.The peroxidase(POD)activity in leaves decreased most significantly under T6 treatment,while the POD activity in roots increased most significantly under T7 treatment.Catalase(CAT)in leaves and roots increased in varying degrees.Increasing the ratio of Na^(+)could induce the tomato leaves and roots to accumulate osmotic adjustment substances to varying degrees.Compared with the control,the change of proline content in T7 treatment was the most significant.The result of membership function analysis showed that all indexes of tomato seedlings under T3 treatment were better than other treatments.In summary,an appropriate sodium-potassium ratio can affect growth and development by adjusting the antioxidant defense and osmotic adjustment capabilities of different organs of tomato,and the overall growth of tomato seedlings is better when the ratio of potassium ions to sodium ions is 1∶1.