外施铵态氮水平对银杏叶生长、生理和品质的影响

Effects of external application level of ammonium nitrogen on growth,physiology and quality of Ginkgo biloba leaves

【目的】为叶用银杏的氮肥管理提供参考。【方法】采用盆栽试验,以2年生半同胞家系银杏苗为试验材料,在银杏生长高峰期(5月下旬)施加不同水平铵态氮(0、1、2、4 g/盆),于8月下旬分别测定银杏单叶干质量、单叶面积、比叶干质量、光合色素含量、硝态氮含量、铵态氮含量、硝酸还原酶活性、氮磷钾含量、黄酮醇苷类成分及总黄酮含量,筛选有利于银杏叶片生长、生理代谢和品质提高的外施铵态氮水平。【结果】外施铵态氮水平显著影响银杏叶片的生长、生理和品质,每盆外施铵态氮水平为2 g时,单叶面积、单叶干质量和比叶干质量均达到最高值。随外施铵态氮水平增加,银杏叶片各光合色素含量均呈单峰趋势,在每盆外施铵态氮水平为2 g时达到峰值;叶片铵态氮和硝态氮含量均上升,硝酸还原酶活性下降;氮含量上升,磷含量先上升后下降且在每盆外施铵态氮水平为2 g时最高,钾含量变化不显著。随外施铵态氮水平增加,槲皮素、山奈酚含量均逐渐上升,异鼠李素含量先上升再下降且在每盆外施铵态氮水平为2 g时最高,总黄酮含量先下降再上升且在每盆外施铵态氮水平为4 g时最高。基于主成分分析法,得出各外施铵态氮水平处理的综合得分由高到低依次为2、4、1、0 g/盆。【结论】施入适宜水平的铵态氮可有效促进银杏叶片的生长和黄酮积累,提高其光合效能,综合考虑银杏叶的生长、生理和品质指标,适宜的外施铵态氮水平为2 g/盆。

【Objective】To provide reference for nitrogen management of Ginkgo biloba.【Method】A pot experiment was conducted with 2-year-old and half sib ginkgo seedlings,different levels of ammonium nitrogen(0,1,2,4 g/pot)were applied at the growth peak of G.biloba(late May).In late August,the dry mass of single leaf,area of single leaf,specific leaf dry mass,relative content of chlorophyll,content of photosynthetic pigment,activity of nitrate reductase,content of nitrate nitrogen,content of ammonium nitrogen,content of NPK,content of flavonol glycosides and total flavonoids of G.biloba leaves were determined.vThe suitable level of ammonium nitrogen was selected for the growth,physiological metabolism and quality of G.biloba leaves.【Result】The results showed that the growth and physiology of ginkgo leaves were significantly affected by the external application level of ammonium nitrogen.When the external application level of ammonium nitrogen each basin was 2 g,the dry mass of single leaf,area of single leaf,specific leaf mass all reached the highest value respectively.With the increase of ammonium nitrogen level,the content of photosynthetic pigments showed a single peak trend,and the peak value was reached when the level of ammonium nitrogen applied outside each pot was 2 g.The content of ammonium nitrogen and nitrate nitrogen in leaves both increased,but the activity of nitrate reductase decreased;the content of N increased,the content of P increased firstly and then decreased,which showed highest value when the ammonium nitrogen level was 2 g per pot,and the change of K content was not significant.With the increase of ammonium nitrogen level,quercetin and kaempferol both increased gradually.The content of isorhamnetin increased first and then decreased.The highest content was found at 2 g per pot.The content of total flavonoids decreased firstly and then increased.The highest value was found when the level of ammonium nitrogen applied outside each pot was 4 g.Based on the principal component analysis,the comprehensive scores of each external ammonium nitrogen level treatment were 2,4,1 and 0 g/pot followed the decreased order.【Conclusion】The application of appropriate level of ammonium nitrogen could effectively promote the growth and flavonoids accumulation of G.biloba leaves and improve their photosynthetic efficiency.Considering the growth index,physiological index and quality of G.biloba leaves,the appropriate ammonium nitrogen level is 2 g/pot.