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通过水培试验 ,利用15N示踪技术研究了甜椒 (CapsicumannuumL .)始花期吸收的氮素在体内的动态分配规律。结果表明 :甜椒营养器官干物质积累动态呈快速直线增长趋势 ,而果实则从盛采前期开始超过其它器官。根与果实含氮量从始采期开始一直维持在同一水平 ;叶片中氮的含量则随生长发育而不断下降。在果实盛采期 ,叶片、果实和根中的氮素含量差异不明显 ,但是均比茎和侧枝高两倍。甜椒植株各器官的氮素积累动态与干物质积累动态相似。在始花期通过根吸收的大部分标记态氮首先分配、贮存在叶片中 ,吸收后第二周发现有 1/2的标记态氮运转到了植物的新生部分 ,至吸收后的第四周标记态氮运转显著下降 ,但是 ,在吸收后的第六周仍然发现有小部分标记态氮运转到了新生部分。说明新近吸收的氮素在甜椒体内的再运转相对容易 ,其再利用率也高 ,随着在植物体内某器官存在时间的延长其再利用率逐渐降低。在整个果实收获期间 ,甜椒不同器官之间以果实对氮素的竞争力最强。在整株水平上 ,始花期吸收的标记态氮从营养器官向生殖器官的运转 ,既受到氮素竞争库 (果实 )强度和容量的影响 ,也受到时间因素的制约。
Through hydroponics experiment, 15N tracing technique was used to study the dynamic distribution of nitrogen absorbed in the initial flowering stage of pepper (Capsicum annuum L.). The results showed that the dynamic accumulation of dry matter of sweet pepper nutrition organs showed a rapid linear growth trend, while the fruit began to surpass other organs from the early harvesting stage. Nitrogen content in roots and fruits maintained at the same level from the beginning of the harvesting period. The content of nitrogen in leaves decreased with the growth and development. The nitrogen content in leaves, fruits and roots was not significantly different during fruit full harvest, but both were twice as high as stems and collaterals. The dynamics of nitrogen accumulation in organs of sweet pepper plants was similar to that of dry matter accumulation. At the beginning of flowering, most of the labeled nitrogen absorbed by the roots was first distributed and stored in the leaves. In the second week after the absorption, one half of the labeled nitrogen was transported to the new part of the plant and the fourth week after the absorption Nitrogen transport decreased significantly, but a small portion of the labeled nitrogen was still found circulating into the nascent portion during the sixth week after it was absorbed. It shows that the newly absorbed nitrogen is relatively easy to re-operate in the sweet pepper and its reutilization rate is also high. The reutilization rate of the nitrogen gradually decreases with the extension of the organ in the plant. During the whole fruit harvest, the sweet pepper has the strongest competition for nitrogen among different organs. At the whole plant level, the uptake of labeled nitrogen from the vegetative organs to the reproductive organs was affected both by the strength and the capacity of the nitrogen pool (fruit) and by the time factor.