夏季叶施^(15)N-硫铵果梅对^(15)N的吸收与运转

Studies on the Absorption and Transportation of ^(15)Nin Prunus mume Trees Following Summer Leaf-applicationof ^(15)N-labelled Ammonium Sulphate

以田间 7a生细叶青梅 /毛桃为试材 ,研究了 7月初叶施15N - (NH4 ) 2 SO4 后 ,果梅吸收与运转15N的特性。结果表明 :至同年 9月中旬 ,各器官中NDFF顺序为 :叶 >当年生枝 >2、 3年生枝。至休眠期 ,花中NDFF远高于同期其它器官 ,居各器官之首。至来年 4月新梢旺长期 ,新梢和幼果中NDFF远高于同期多年生器官 ,其中新梢中NDFF为同期幼果的 2 2 6倍 ;比较处理枝和对照枝上新梢的含氮量 ,前者较后者高 14 3% ;此外 ,在此期相邻枝的新梢和幼果中也检测到了15N ,但浓度很低。以上结果表明 :夏季叶施15N后 ,在秋季叶片衰老脱落前 ,15N可由叶中回撤至树体内贮藏起来 ,且局部回流贮藏的氮素营养有局部利用的特点。夏季叶施氮肥可促进花芽分化和来春新生器官的建造 ,尤其是对新梢生长有显著的促进作用 ;

Mature trees of Prunus mume trees/wild peach were fertilized with 15N-labelled ammonium sulphate via leaf in summer. The 15N absorbed concentrated greatly in leaves and 1-year branch on 93th days after treatment. During dormancy, the NDFF of flower bud was the highest. In the next season, the NDFF of spring shoot and young fruit was higher than other organs, and the NDFF of the former was 2.26 times higher than that of the later. The nitrogen concentration of spring shoots developing on 15N applied 2-year branches was 14.3% higher than on water-applied branches. At the same time,a little 15N transported in the new organs near treated branches. Following summer leaf-application 15N, the withdrawn 15N from fallen leaves shifted in trees in winter, and local withdrawn 15N remobilized in original organs during spring. Summer leaf-application nitrogen was advantage to spring shoot, flower-bud differentiation and fruit-setting, and little effect to perennial organ-developing and root-expanding.