Aims

Diversity of root systems among genetic resources can contribute to optimize water and nutrient uptake. Topsoil exploitation vs. deep soil exploration represent two contrasting ideotypes in relation to resource use. Our study reveals how rooting patterns changed between wheat wild progenitors and landraces in regard to these ideotypes.

Methods

Root (partitioning, morphology, distribution, elongation, anatomy) and shoot traits (dry-matter, leaf area, assimilation) of durum landraces, wild emmer and wild einkorn from Iran, Syria, Turkey and Lebanon were phenotyped using the GrowScreen-Rhizo platform. Distinctive rooting patterns were identified via principal component analysis and relations with collection site characteristics analyzed.

Results

Shoot trait differentiation was strongly driven by seed weight, leading to superior early vigor of landraces. Wild progenitors formed superficial root systems with a higher contribution of lateral and early-emerging nodal axes to total root length. Durum landraces had a root system dominated by seminal axes allocated evenly over depth. Xylem anatomy was the trait most affected by the environmental influence of the collection site.

Conclusions

The durum landrace root system approximated a deep soil exploration ideotype which would optimize subsoil water uptake, while monococcum-type wild einkorn was most similar to a topsoil exploiting strategy with potential competitive advantages for subsistence in natural vegetation.

中文翻译：

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深层土壤勘探与表土开发：小麦地方品种和野生近缘种之间独特的生根策略

目标

遗传资源中根系的多样性有助于优化水和养分的吸收。表土开发与深层土壤勘探代表了与资源利用相关的两种截然不同的观念。我们的研究揭示了小麦野生祖先和地方品种在这些独特型方面的生根模式如何变化。

方法

使用 GrowScreen-Rhizo 平台对来自伊朗、叙利亚、土耳其和黎巴嫩的硬粒小麦地方品种、野生二粒小麦和野生单粒小麦的根（分区、形态、分布、伸长、解剖）和枝条性状（干物质、叶面积、同化）进行表型分析. 通过主成分分析确定了独特的生根模式，并分析了与收集地点特征的关系。

结果

芽性状分化受种子重量的强烈驱动，导致地方品种的早期活力优越。野生祖细胞形成浅根系，横向和早期出现的节轴对总根长的贡献更高。硬粒小麦地方品种的根系由均匀分布在深度上的精轴支配。木质部解剖结构是受采集点环境影响最大的特征。

结论

硬粒小麦地方品种根系近似于一种可优化地下吸水的深层土壤勘探模式，而单球菌型野生单粒小麦最类似于表土开发策略，具有潜在的竞争优势，可在自然植被中生存。