Comparing the classical permanent wilting point concept of soil (−15,000 hPa) to biological wilting of wheat and barley plants under contrasting soil textures
Comparing the classical permanent wilting point concept of soil (−15,000 hPa) to biological wilting of wheat and barley plants under contrasting soil textures
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将经典的土壤永久萎蔫点概念（−15,000hPa）与对比土壤质地下小麦和大麦植物的生物枯萎进行比较
DOI：
10.1016/j.agwat.2019.105965
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发表时间：
2020
影响因子：
6.7
通讯作者：
A. L. D. Paula
中科院分区：
文献类型：
--
作者：
L. H. Wiecheteck;N. F. Giarola;Renato P. de Lima;C. A. Tormena;L. C. Torres;A. L. D. Paula
最近的研究表明，永久萎缩点受土壤性质和植物耐旱机制的影响。这项研究旨在评估小麦和大麦品种的生物萎缩点(BWP)发生的土壤基质势(PWP)，并与具有不同质地的土壤(PWP土)在基质势为-15,000 HPA处的永久萎萎点的经典概念进行比较。这项研究是在温室条件下进行的，试验采用完全随机设计的双因素方案，包括三种土壤质地(沙质壤土-SL、沙质粘壤土-SCL和粘土-C)和四种植物(两种作物(小麦和大麦)和每种作物两个品种)。采用95%可信区间比较治疗方法。结果表明，BWP植物可以在>；−15,000 hpa的基础电位值下发生，即比经典PWP土壤更潮湿的条件。与砂质土壤相比，粘性土壤中种植的植物在较低的基质势下枯萎，这可能与砂质土中基质势较高时发生的水力切断有关。大麦植株比小麦植株对水分亏缺更为敏感。大麦植株的BWP植株可能出现在与土壤质地无关的>；−15,000 hpa处，而小麦植株在>；−15,000 hpa处萎靡不振，仅在沙质土壤中(例如−1,637至−2,417 hpa)。我们的结果表明枯萎依赖于土壤质地，砂质土比粘土土在更高的基质势(即在更潮湿的土壤条件下)发生萎萎。此外，植物/品种表现出不同的抗旱机制，小麦能够在比大麦低得多的基质势(在干燥的土壤条件下)吸收水分。因此，不同物种和品种的枯萎基质势阈值并不是一致的。
Recent studies have shown that the permanent wilting point is influenced by soil properties and plant drought-tolerance mechanisms. This study was designed to evaluate the soil matric potential at which the biological wilting point (BWPplant) of wheat and barley cultivars occurs compared to the classic concept of the permanent wilting point at a matric potential of -15,000 hPa for soils (PWPsoil) with contrasting textures. The study was performed under greenhouse conditions with the experiment arranged in a completely randomised design in a double factorial scheme with three soil textures (sandy loam - SL, sandy clay loam - SCL and clay - C) and four plants (two crops (wheat and barley) and two cultivars for each crop). The 95 % confidence intervals were used to compare treatment means. The results revealed that BWPplantcould occur at matric potential values > −15,000 hPa, i.e. wetter conditions than for the classical PWPsoil. Plants cultivated in clay soils withered at lower matric potentials than those in sandy soils, which could be related to a hydraulic cut-off that occurs at higher matric potentials in sandy soils. Barley plants were more sensitive to water deficits than wheat plants. The BWPplantfor barley plants could occur at matric potentials values > −15,000 hPa, independently of soil texture, whereas wheat plants wilted at matric potentials > −15,000 hPa only in sandy soils (e.g. −1,637 to −2,417 hPa). Our results suggest that wilting depends on soil texture, with an occurrence of wilting at higher matric potentials (i.e. at wetter soil conditions) for sandy soils than for clay soils. Furthermore, plants/cultivars exhibit various tolerance mechanisms to drought, and wheat is able to take up water at considerably lower matric potentials (at dryer soil conditions) than barley. Thus, the wilting matric potential threshold across various species and cultivars is not uniform.