果梅对秋施^(15)N-硫铵的吸收与利用

Studies on the Absorption and Distribution of 15N-labelled Ammonium Calcium to Prunus mume Following Autumn Application

以细叶青梅 /桃砧为试材 ,研究了秋施 15N -硫铵条件下氮的吸收、分配、贮藏和利用。休眠期果梅各器官均有贮氮能力 , 15N浓度根系大于多年生枝。秋施氮肥后 ,冬季花中 15N浓度显著高于同期其它器官 ;春季果仁 >新梢 >果核 >果肉 ,说明此期果仁争夺氮素营养的能力最强。新梢停长后 ,当年生枝和叶中 15N浓度显著下降 ,而多年生器官在 4～ 6月均有所上升 ,而 6～ 9月又都大幅度下降 ,表明此期为多年生器官加粗和新根大量生长之际 ;当年生枝 15N浓度虽有所下降 ,但始终高于同期多年生器官 ,表明贮氮对当年生枝的花芽分化有持续作用。秋季落叶后 ,衰老器官中回撤的氮素营养就近运输 ,就近贮藏。次年春 ,局部贮藏的氮素营养仍能重新为建造新生器官所使用。所以果梅体内氮素营养有随生长中心转移而转移 ,且可较长时期重复利用的特性。

Mature plants of Prunus mume/peach rootstock were fertilized with 15N-labelled ammonium calcium in autumn.Treatment with autumn application augmented 15N-storage in roots and the perennial branches and promoted flower-bud differentation in winter.During shoot rapid-growing period,kernel absorbed more nitrogen than did the new shoots;After then, 15N in the new shoots was recovered to perennial tissues,perennial organs- thickening became the growing-centre.The 15N concentration in the current branchs was higher than the perennial branchs,the storage N could promote the next year flower-bud differentation.The withdrawed 15N from falled organs was remobilized in near tissues during dormant period.In the following season,the withdrawed 15N was translocated to new organs.The remobilization and distribution of N were highly correlated with the centre of growth and development in Prunus mume.The absorbed N following autumn application could be utilized for a long time.