| 摘要: |
| 采用全根、分根培养系统，研究根构型参数对氮素供应方式和水平的适应性变化。结果表明：水稻根构型参数对供氮量和供氮方式具有适应性反应。分根供氮时，无论供氮量高低，供氮均能诱导根系生长发育，表现为供氮侧侧根长、根表面积、根系体积、根重等根构型参数明显高于无氮一侧，但是根系平均直径明显变细。分根处理，供氮侧中量和高量供氮使侧根长分别增加9％和91％，而在无氮侧，侧根长分别减少54％和42％；供氮侧根表面积分别增加20.1％和87.9％，无氮侧分别减少45.2％和33.3％；供氮侧根系体积分别增加32.4％和88.0％，无氮侧根体积分别减少33.9％和22.4％。供氮量适当时（N40），侧根长、根表面积、根体积的增加归因于生物量的增加；而在供氮量多时（N80），侧根长、根表面积、根体积的增加既有生物量增加的作用，又有比根长、比表面积的直接贡献。研究结果表明，根构型参数变化是水稻适应不同氮素供应的可能机理之一。 |
| 关键词: 水稻 氮素供应 干物质分配 根构型参数 |
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| 基金项目:国家自然科学基金资助项目(39970420,30270769)；中德国际合作项目；广东省科技厅国际合作项目(C50208) |
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| Growth and adaptive changes of rice (Oryza sativa L.) root architecture in response to nitrogen supply |
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| Abstract: |
| Whole and splitting root-box system and quartz sand culture were conducted to study the effects of location and level of nitrogen on the allocation of carbohydrate represented by dry matter and parameters of rice root architecture.Results showed that the amount and location of nitrogen supply have affected significantly on allocation of the dry matter between up ground part and under ground one and on parameters of rice root architecture such as root length,root surface area,root volume as well as on root distribution.Biomass of up ground parts of the crop increased with increase of nitrogen fertilization under the condition of whole root supplied nitrogen.Moderate amount of nitrogen fertilization would promote root growth,whereas excessive nitrogen could block root growth.Under condition of half roots supplied with nitrogen,both moderate and high rate of nitrogen would induce root growth and development.Lateral root length,root surface area,root volume were increased by 9% to 91%,20.1% to 87.9% and 32.4% to 88.0% respectively.However,root diameter decreased in the part of nitrogen treatment.The increase of lateral root length,root surface area,root volume could be attributed to the increase of biomass at the moderate nitrogen supply,nevertheless the increase of these parameters was not only related to increase of biomass,but also contributed directly to lateral root length and root surface area per biomass under high rate of nitrogen.It could be concluded that the change of the root length,surface area and volume is one of the adaptive mechanism of rice to nitrogen fertilizer. |
| Key words: rice (Oryza sativa L.) nitrogen supply allocation of dry matter parameters of rice root architecture |
