Background and Aims Domesticated maize (Zea mays ssp. mays) generally forms between two and six seminal roots, while its wild ancestor, Mexican annual teosinte (Zea mays ssp. parviglumis), typically lacks seminal roots. Maize also produces larger seeds than teosinte, and it generally has higher growth rates as a seedling. Maize was originally domesticated in the tropical soils of southern Mexico, but it was later brought to the Mexican highlands before spreading to other parts of the continent, where it experienced different soil resource constraints. The aims of this study were to understand the impacts of increased seminal root number on seedling nitrogen and phosphorus acquisition and to model how differences in maize and teosinte phenotypes might have contributed to increased seminal root number in domesticated maize. Methods Seedling root system architectural models of a teosinte accession and a maize landrace were constructed by parameterizing the functional–structural plant model OpenSimRoot using plants grown in mesocosms. Seedling growth was simulated in a low-phosphorus environment, multiple low-nitrogen environments, and at variable planting densities. Models were also constructed to combine individual components of the maize and teosinte phenotypes. Key Results Seminal roots contributed ~35 % of the nitrogen and phosphorus acquired by maize landrace seedlings in the first 25 d after planting. Increased seminal root number improved plant nitrogen acquisition under low-nitrogen environments with varying precipitation patterns, fertilization rates, soil textures and planting densities. Models suggested that the optimal number of seminal roots for nutrient acquisition in teosinte is constrained by its limited seed carbohydrate reserves. Conclusions Seminal roots can improve the acquisition of both nitrogen and phosphorus in maize seedlings, and the increase in seed size associated with maize domestication may have facilitated increased seminal root number.

中文翻译：

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与驯化相关的精根数量增加可改善玉米幼苗的氮和磷获取

背景和目标 驯化玉米（Zea mays ssp. mays）通常形成两到六个精根，而其野生祖先墨西哥一年生大蜀黍（Zea mays ssp. parviglumis）通常缺乏精根。玉米还产生比类蜀黍更大的种子，并且它作为幼苗通常具有更高的生长速度。玉米最初是在墨西哥南部的热带土壤中驯化的，但后来被带到墨西哥高地，然后传播到该大陆的其他地区，在那里它经历了不同的土壤资源限制。本研究的目的是了解增加的精根数量对幼苗氮和磷获取的影响，并模拟玉米和类蜀黍表型的差异如何可能导致驯化玉米的精根数量增加。方法 使用生长在中宇宙的植物，通过参数化功能结构植物模型 OpenSimRoot 来构建大蜀黍种质和玉米地方品种的幼苗根系结构模型。在低磷环境、多个低氮环境和可变种植密度下模拟幼苗生长。还构建了模型以结合玉米和类蜀黍表型的各个成分。主要结果 种子根贡献了约 35% 的氮和磷，这些氮和磷是玉米地方品种幼苗在种植后的前 25 天获得的。在具有不同降水模式、施肥率、土壤质地和种植密度的低氮环境下，增加精根数量可改善植物氮的获取。模型表明，类蜀黍营养获取的最佳精根数量受到其有限的种子碳水化合物储备的限制。结论 精根可以提高玉米幼苗对氮和磷的吸收，与玉米驯化相关的种子大小的增加可能促进了精根数量的增加。