红树莓叶片早衰对其营养成分含量和主要酶活性的影响

Effects of leaf presenility on nutrition and main enzyme activity in red raspberry(Rubus idaeus L.)

【目的】探究双季红树莓果实成熟盛期树体早衰对其叶片营养及酶活性变化的影响,为红树莓关键发育时期的合理施肥及延缓叶片早衰提供理论依据。【方法】以双季红树莓‘海尔特兹’为试验材料,对该时期发生不同程度早衰的初生茎不同部位叶片矿质元素含量、抗氧化酶活性及丙二醛含量进行测定,揭示影响红树莓叶片早衰的主要因素。【结果】在同一时期不同发育阶段(营养生长期、初花期、盛花期、果实成熟初期、果实成熟盛期)初生茎的叶片中矿质元素含量不同,营养生长期至果实成熟盛期,氮元素含量下降明显,果实成熟盛期早衰叶片氮含量显著低于营养生长期正常叶片;果实成熟盛期上、下部早衰叶片磷元素含量稳定;正常叶片钾元素含量显著高于早衰叶片,而钙、镁、锰、锌含量显著低于早衰叶片。果实成熟初期上、下部叶片SOD活性均为最高,分别为1.75和0.50 U/(g·min),MDA含量最低,分别为5.24和3.64 U/(g·min),上部叶片POD活性最高,为29.48 U/(g·min);营养生长期上、下部叶片CAT活性最高,分别为61.83和31.99 U/(g·min)。【结论】营养生长期至果实成熟盛期,正常叶片中大量元素氮、钾含量显著高于早衰叶片,这是由于红树莓开始进入生殖生长期,营养消耗加快,因此在初花期之前应及时补充肥料。正常叶片中钙、镁和铁含量显著低于早衰叶片,且钙与镁、钙与铁、镁与铁的含量间均呈极显著正相关,相关系数分别为0.97、0.94、0.90,为避免叶片发生早衰现象,降低早衰程度,应减少钙、镁、铁肥的施入。

【Objective】The present study aims to find out the effect of tree presenilityon the changes of leaf nutrition and enzyme activity in fruit maturity period of annual fruiting raspberry(Rubusidaeus L.)to provide a theoretical basis for rational fertilization and delay leaf presenility during the key development period of red raspberry.【Method】‘Heritage’raspberry were used as materials,and the contents of mineral elements,antioxidant enzyme activities and malondialdehyde in leaves of different parts of the primary stem with different degrees of presenility in this periodwere determined toclarify the main factors that affect the leaf presenility.【Result】The contents of mineral elements in the leaves of primary stem were different in different developmental stages(vegetative growth stage,primary flowering stage,full flowering stage,primary ripening stage,full ripening stage)in the same period.The content of nitrogen decreased significantly from the vegetative growth stage to the full ripening stage.The content of nitrogen in the leaves with early senescence during full ripening stage was significantly lower than that in the normal leaves during vegetative growth stage.In the full ripening stage,the content of phosphorus in the upper and lower leaves of early senescence remained stable,and the content of K element in normal leaves was significantly higher than that in early senescence leaves,while the content of Ca,Mg,Mn,and Zn was significantly lower than that in early senescence leaves.At the primary ripening stage,the SOD activity in the upper and lower leaves was the highest,which was 1.75 and 0.50 U/(g·min),respectively,and the MDA content was the lowest,which was 5.24 and 3.64 U/(g·min).Moreover,POD activity of the upper leaves was highest at 29.48 U/(g·min).At the vegetative growth stage,CAT activity of the upper and lower leaveswas highest at 61.83 and 31.99 U/(g·min),respectively.【Conclusion】During the vegetative growth stage to the full ripening stage,the content of large amounts of N and K in the normal leaves was significantly higher than those in the premature senescence leaves caused by red raspberry began to enter reproductive growth and nutrient consumption accelerated.Therefore,fertilizer should be added in time before the primary flowering stage.The contents of Ca,Mg and Fe in normal leaves were significantly lower than those in the premature senescence leaves,and Ca and Mg,Ca and Fe,Mg and Fe were extremely significantly positively correlated.The correlation coefficients were 0.97,0.94 and 0.90,respectively.In order to avoid and reduce the premature senescence of leaves,the application of Ca,Mg and Fe fertilizers should be reduced.