Rice leaf growth and water potential are resilient to evaporative demand and soil water deficit once the effects of root system are neutralized
Rice leaf growth and water potential are resilient to evaporative demand and soil water deficit once the effects of root system are neutralized
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DOI：
10.1111/j.1365-3040.2010.02145.x
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发表时间：
2010-08-01
影响因子：
7.3
通讯作者：
Tardieu, Francois
中科院分区：
文献类型：
--
作者：
Parent, Boris;Suard, Benoit;Tardieu, Francois
众所周知，水稻对土壤水分亏缺和蒸发需求很敏感，其中适应低地的基因型最为敏感。我们分析了七种水稻基因型的植物水分关系和叶片伸长率（LER）对土壤水分状况和蒸发需求的响应，这些基因型属于不同物种、亚种，无论是适应旱地还是低地。在所考虑的土壤水势范围内（0至-0.6 MPa），控制气孔导度，使白天叶片水势在水分充足、干旱或洪水条件下相似（等水行为）。在相同的三种条件下观察到 LER 对蒸发需求的敏感性较低，基因型之间差异较小，敏感性低于玉米。 LER对土壤水分亏缺的敏感性与玉米相似。在高地基因型中观察到敏感性低于低地基因型的趋势，但差异小于预期。我们的结论是，水稻叶片水分状况和叶片伸长对水分亏缺并不特别敏感。水稻对干旱敏感的主要原因可能是其根系较差，在本文提出的研究中，通过在土壤完全被所有基因型的根部定植的盆中种植植物，缓解了其影响。
Rice is known to be sensitive to soil water deficit and evaporative demand, with a greatest sensitivity of lowland-adapted genotypes. We have analysed the responses of plant water relations and of leaf elongation rate (LER) to soil water status and evaporative demand in seven rice genotypes belonging to different species, subspecies, either upland- or lowland-adapted. In the considered range of soil water potential (0 to -0.6 MPa), stomatal conductance was controlled in such a way that the daytime leaf water potential was similar in well-watered, droughted or flooded conditions (isohydric behaviour). A low sensitivity of LER to evaporative demand was observed in the same three conditions, with small differences between genotypes and lower sensitivity than in maize. The sensitivity of LER to soil water deficit was similar to that of maize. A tendency towards lower sensitivities was observed in upland than lowland genotypes but with smaller differences than expected. We conclude that leaf water status and leaf elongation of rice are not particularly sensitive to water deficit. The main origin of drought sensitivity in rice may be its poor root system, whose effect was alleviated in the study presented here by growing plants in pots whose soil was entirely colonized by roots of all genotypes.