不同供镁水平对杉木幼苗叶片抗氧化酶活性和叶绿素含量的影响

Effects of Different Levels of Magnesium Supply on Antioxidant Enzyme Activities and Chlorophyll Content in Leaves of Cunninghamia lanceolata Seedlings

【目的】以1年生杉木无性系为研究对象,评价不同供镁水平对杉木幼苗叶片抗氧化酶活性和叶绿素含量的影响。【方法】通过室内沙培盆栽试验,分析0 mmol/L(M0)、0.2 mmol/L(M1)、0.4 mmol/L(M2)、0.8 mmol/L(M3)4个不同供镁水平处理下1年生杉木无性系叶片丙二醛含量、抗氧化酶活性、叶绿素含量的影响。【结果】随处理时间延长,正常供镁(M0)杉木幼苗叶片丙二醛(MDA)含量呈先上升后下降的趋势,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性、叶绿素a(Cha)、叶绿素b(Chb)、叶绿素总量(Chl)不断提高。0.4 mmol/L的镁处理(M2)中MDA含量,SOD、POD活性,Cha、Chb、Chl含量的变化趋势与M0处理相似,且各含量均与M0处理存在显著差异。各生理生化指标相关性分析表明:MOD含量与POD活性呈显著负相关(P<0.05),与SOD、POD活性无显著相关性,Cha、Chb、Chl含量与SOD、POD活性呈极显著正相关(P<0.01),Chb含量与CAT活性呈极显著负相关(P<0.01)。【结论】M0处理使杉木幼苗叶片细胞膜系统损伤,过氧化物促使抗氧化酶活性升高,叶绿素合成减缓,影响光合作用速率。M2处理可降低损伤细胞膜的有害物质含量,提高细胞膜系统结构稳定性和叶绿素含量,利于光合速率提升,促进杉木幼苗生长。研究结果从杉木营养学的角度为杉木壮苗培育提供理论依据。

[Objective]One-year-old Cunninghamia lanceolata clones were used as research objects to evaluate the effects of differentlevelsof magnesium supply on antioxidant enzyme activities and chlorophyll content in leaves of Cunninghamia lanceolata seedlings.[Method]Through the indoor sandnutrient liquid culture pot experiment,the contents of malondialdehyde,antioxidant enzymes and chlorophyll in leaves of Cunning⁃hamia lanceolata clones were studied with 4 different magnesium levels.The concentrations were:0mmol/L(M0),0.2 mmol/L(M1),0.4 mmol/L(M2),0.8 mmol/L(M3).[Result]With the treatment time increasing,the content of malondialdehyde(MDA)in the leaves of normal magnesium(M0)increased first and then decreased,the activities of superoxide dismutase(SOD),peroxidase(POD),hydrogen peroxide(CAT),contents of chlorophyll a(Cha),chlorophyll b(Chb),total chlorophyll(Chl)increased continuously.The content of MDA,the activities of SOD,POD,the content of Cha,Chb and Chl in0.4mmol/L magnesium treatment(M2)were similar to those of M0’s,and each content was significantly different from M0’s.Correlation analysis of physiological and biochemical indexes showed that there was a significant negative correlation between MOD content and POD activity(P<0.05),and no significant correlation with the activities of SOD and POD.The contents of Cha,Chb and Chl were positively correlated with the activities of SOD and POD(P<0.01),Chb content was negatively correlated with CAT activity(P<0.01).[Conclusion]M0 treatment damaged the cell membrane ststem ofCunning⁃hamia lanceolataseedling leaves,peroxide promoted the activity of antioxidant enzymes,chlorophyll synthesis slowed,affecting the rate of photosynthesis.M2 treatment could reduce the harmful substance content of damaged cell membrane,improve the structural stability and increase chlorophyll content of cell membrane system,the photosynthetic rate and the growth of Cunninghamia lanceolata seedlings.The research results provide a theoretical basis for the cultivation of Cunninghamia lanceolata seedlings from the perspective of nutrition.