甜椒始花期氮素分配动态的研究

 利用¹⁵N 示踪技术研究了营养液培养甜椒始花期吸收的氮素在体内的动态分配规律。结果表明: 根与果实中氮的含量在始采期以后保持稳定; 而叶片中氮的含量则随生育进程迅速下降, 盛采期时与果实和根相近, 且两倍高于茎和侧枝。始花期由根吸收的标记氮主要贮存在叶片中, 2 周后向新生器官的运转率高达50. 6%, 4 周后达到57. 1%, 6 周后为58. 0%, 说明越是新近吸收的氮素越容易被再度运转到其它器官, 随着在体内时间的延长, 氮的再运转能力逐渐降低。开花后2 周收获的果实中标记氮占始花期吸收总量的3. 24%, 第3、4、6 周分别为11. 12%, 9. 49%和4. 75%。果实是甜椒体内氮的强力库, 氮素竞争力最强。

Distribution Dynamics of Nitrogen in the Organs of Sweet Pepper ( Capsicum annuum L. ) at Early Flowering Stage

Sweet pepper( Capsicum annuum L.)grown in water culture was used to study the distribution dynamics of nitrogen absorbed at early flowering stage with 15 N tracer technique.The results obtained are as follows: The nitrogen concentration in root and fruit was kept steady from the early picking stage.In the leaves it decreased rapidly with growth and development and was not much different from the root and fruit at the profuse fruiting stage but it was two times higher than that in the stem and branch.The nitrogen accumulation dynamics was similar to the accumulation dynamics of the dry matter.Most of the labeled nitrogen,which was absorbed at early flowering stage by root,have been remained in leaves and its translocation ratio was 50.6% from the leaves to the new organs after two weeks,and 57.1% and 58.0% after 4 weeks and 6 weeks respectively,indicating the new absorbed nitrogen is easier to be translocated.The labeled nitrogen in fruit harvested 2 weeks after early flowering stage make up 3.24% of the total labeled nitrogen absorbed at early flowering stage and 11.12%,4.49%, 4.75% for the fruits harvested 3,4 and 6 weeks after early flowering stage respectively.It is indicated that fruit is the strong nitrogen sink in the plant of sweet pepper.It is the fruit that have the most competitive ability of nitrogen.