The potential increased frequency and severity of drought associated with environmental change represents a significant obstacle to efforts aimed at enhancing food security due to its impact on crop development, and ultimately, yield. Our understanding of the impact of drought on crop growth in terms of plant aerial tissues is much more advanced than knowledge of the below-ground impacts. We undertook an experiment using X-ray Computed Tomography that aimed to support measurements of infrared gas exchange from plant shoots with quantification of 3D root architecture traits and the associated soil structural characteristics. Winter wheat (cv. Zebedee) was assessed at two early growth stages (14 and 21 days) under four water treatments (100, 75, 50 and 25 % of a notional field capacity (FC) and across two soil types (sandy loam and clay loam)). Plants generally grew better (to a larger size) in sandy loam soil as opposed to clay loam soil, most likely due to the soil structure and the associated pore network. All plants grew poorly under extreme water stress and displayed optimal growth at 75 % of FC, as opposed to 100 %, as the latter was most likely too wet. The optimal matric potential for root and shoot growth, inferred from the water release curve for each soil type, was higher than that for photosynthesis, stomatal conductance and transpiration suggesting root and shoot growth was more affected by soil water content than photosynthesis-related characteristics under water deficit conditions. With incidences of drought likely to increase, identification of wheat cultivars that are more tolerant of these conditions is important. Studies that consider the impact of water stress on both plant shoots and roots, and the role of the soil pore system such as this offer considerable potential in supporting these efforts.

中文翻译：

---

使用 X 射线计算机断层扫描量化水分亏缺对小麦根和芽生长的影响。


与环境变化相关的干旱频率和严重程度可能会增加，这对加强粮食安全的努力构成了重大障碍，因为它影响作物发育并最终影响产量。我们对干旱对植物气生组织生长影响的了解比对地下影响的了解要先进得多。我们使用 X 射线计算机断层扫描进行了一项实验，旨在支持植物芽红外气体交换的测量，并量化 3D 根结构特征和相关的土壤结构特征。在四种水处理（名义田间持水量 (FC) 的 100%、75%、50% 和 25%）和两种土壤类型（沙壤土和粘壤土））。与粘壤土相比，植物通常在沙壤土中生长得更好（尺寸更大），这很可能是由于土壤结构和相关的孔隙网络所致。所有植物在极端水分胁迫下都生长不良，在 FC 的 75% 时表现出最佳生长，而不是 100%，因为后者很可能太湿。从每种土壤类型的水释放曲线推断，根和芽生长的最佳基质势高于光合作用、气孔导度和蒸腾作用的最佳基质势，表明根和芽生长受土壤含水量的影响比光合作用相关特性的影响更大。缺水条件。随着干旱发生率可能增加，鉴定对这些条件更耐受的小麦品种非常重要。 考虑水分胁迫对植物芽和根的影响以及土壤孔隙系统的作用的研究为支持这些努力提供了巨大的潜力。