【摘要】 用金冠和红星苹果成年树,于1982和1983年10月下旬～11月上旬,在短果枝叶片施用¹⁵N-尿素,75％进入树体。短果枝木质部和皮部N含量增高,在总N量中来自¹⁵N尿素的百分率分别为5.74～12.7％和8.24～11.9％。第二年大蕾期在花、叶和新梢中均有¹⁵N-尿素N出现,分别可占总N量的1.51～1.87％和1.46～1.88％。在二年生木质部和皮部内仍保留有相当量的¹⁵N-尿素N。秋季经由短果枝运出的¹⁵N,在春天有一部分又回到短果枝中来。由短果枝进入树体的¹⁵N,也可向引入区上下附近的短果枝内运转。秋季叶面施用尿素的短果枝,花的含N百分率高于对照,但受树整体调节的影响,短果枝总含N量的百分率未见增高。在幼果期仍可测得¹⁵N在果中的分配。本文还讨论了该方法的可行性及生产上的意义。更多还原

【Abstract】 15N labelled urea was applied on spur leaves on mature apple trees cv. Golden Delicious and Starking in late October 1982 and early No-vember 1983.The results showed that during the period from application to leaf-fall, about 75% of the 15N~urea entered the trees. The N level of the xylem and bark of the spur was increased. By total nitrogen, the percentage of NDFF was 5.74~12.7% in 1982 and 8.24-11.9% in 1983. At the pink stage following the year of application, 15N~urea was found in the flowers, spur leaves and the bourse of the spurs. The percentage of NDFF of these organs was 1.51-1.87% and 1.46~1.88% in 1983 and 1984 and respectively. 15N-urea was also found in the xylem and bark of the older twigs. The 15N-urea which entered the branches via the spur the preceeding year, were transported back into the spur again in the spring. It could be translocated also into the spurs located upon or below the treated spurs.While the nitrogen level in the flowers on the spurs treated with 15N-urea was higher than the control, that in the spurs was the same between them. 15N-urea was also detected in the young fruits. The significance of this method was discussed.更多还原