持续供氮对长白落叶松播种苗生长及抗寒性的影响  

Influence of continually supplementing nitrogen on the quality of Larix olgensis seedlings

作　　者：祝燕[1] 李国雷[1] 李庆梅[2] 刘勇[1] 邹尚庆[1] 蒋乐[1] 

机构地区：[1]北京林业大学省部共建森林培育与保护教育部重点实验室,北京100083 [2]中国林业科学研究院林业研究所,国家林业局林木培育重点实验室,北京100091

出　　处：《南京林业大学学报（自然科学版）》2013年第1期44-48,共5页Journal of Nanjing Forestry University：Natural Sciences Edition

基　　金：中央高校基本科研业务费专项资金(JD2011-3,TD2011-8)

摘　　要：养分加载是调控苗木质量的重要措施。在7月份常规施肥的基础上,8、9、10月份对长白落叶松播种苗分别进行持续追肥,研究不同的氮加载量对苗木形态指标、养分浓度、抗寒性的影响。结果表明:持续施氮后,长白落叶松播种苗苗高、地径分别比未施肥的苗木高出35.4%～52.4%和11.3%～19.0%;与常规施肥相比,持续供氮对苗高、地径均无显著影响。随氮加载量的增加,茎氮浓度无显著变化,而根氮浓度持续增大,根对氮加载比茎敏感;氮加载后苗木生物量增加显著,但处理间无明显差异。在1.5～-50℃整个降温过程中,施用氮肥苗木的相对电导率均显著小于未施氮肥的苗木;在1.5～-20℃间,施氮的苗木相对电导率未出现显著差异,相对电导率值为13.57%～23.12%;但温度由-30℃降至-50℃时,相对电导率值均急剧上升至23.28%～35.59%;360、420 kg/hm2施氮处理的苗木相对电导率显著低于常规施肥的苗木,表明对长白落叶松播种苗进行氮加载可能有利于提高苗木抗寒性。Nutrient loading has been widely used as an important cultural technique to regulate seedling quality,which can build higher nutrient reserves in seedlings during nursery culture.To test the influence of nutrient loading on the quality of Larix olgensis,one-year-old seedlings were subjected to a continual supplement of nitrogen in August,September and October（equivalent applications of 240,360 and 420 kg/hm2 N,respectively） after the ordinary fertilization in July.At the time of harvest,seedling height and root collar diameter increased by 35.4%-52.4% and 11.3%-19.0% compared with ordinary fertilization.There were no significant differences in morphology and shoot N concentration among seedlings with different N loadings,while the root N concentration increased significantly with fertilization application,suggesting root may be more sensitive to N loading than shoot.The biomass of seedlings increased significantly compared with ordinary fertilization,but didn＇t show any differences among the treatments.On all the temperatures treatments,the values of freeze-induced electrolyte leakage（FIEL） in the N-fertilized seedlings was lower than that of unfertilized,which ranged from 13.57% to 23.12% at temperature above-20 ℃.However,once the temperature declined as low as-30 ℃,FIEL values increased sharply to 23.28%-35.59%,whereas that of the seedlings with 360 and 420 kg/ hm2 N treatments was significantly lower,demonstrating that the advantage of N loading practices having a possibility of enhancing the cold resistance of Larix olgensis seedling.

关 键 词：长白落叶松 抗寒性 持续供氮 养分加载 苗木质量 

分 类 号：S723[农业科学—林木遗传育种]