In a given root system, individual roots usually exhibit a rather homogeneous tip structure although highly different diameters and growth patterns, and this diversity is of prime importance in the definition of the whole root system architecture and foraging characteristics. In order to represent and predict this diversity, we built a simple and generic model at root tip level combining structural and functional knowledge on root elongation. The tip diameter, reflecting meristem size, is used as a driving variable of elongation. It varies, in response to the fluctuations of photo-assimilate availability, between two limits (minimal and maximal diameter). The elongation rate is assumed to be dependent on the transient value of the diameter. Elongation stops when the tip reaches the minimal diameter. The model could satisfactorily reproduce patterns of root elongation and tip diameter changes observed in various species at different scales. Although continuous, the model could generate divergent root classes as classically observed within populations of lateral roots. This model should help interpret the large plasticity of root elongation patterns which can be obtained in response to different combinations of endogenous and exogenous factors. The parameters could be used in phenotyping the root system.

中文翻译：

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建模与同化供需相关的根部直径和伸长率的时间变化。

在给定的根系中，单个根通常显示出相当均匀的尖端结构，尽管直径和生长模式差异很大，并且这种多样性对于整个根系结构和觅食特性的定义至关重要。为了表示和预测这种多样性，我们在根尖级别构建了一个简单而通用的模型，结合了有关根伸长的结构和功能知识。反映分生组织大小的尖端直径用作伸长的驱动变量。响应光同化可用性的波动，它在两个限制（最小和最大直径）之间变化。假定伸长率取决于直径的瞬态值。当尖端达到最小直径时，伸长率停止。该模型可以令人满意地重现各种物种在不同尺度下观察到的根伸长和尖端直径变化的模式。尽管是连续的，但该模型可能会产生不同的根类，如在侧根种群中经典观察到的。该模型应有助于解释根系延伸模式的可塑性，该模式可响应于内源性和外源性因素的不同组合而获得。这些参数可用于根系统的表型分析。该模型应有助于解释根系延伸模式的可塑性，该模式可响应于内源性和外源性因素的不同组合而获得。这些参数可用于根系统的表型分析。该模型应有助于解释根系延伸模式的可塑性，该模式可响应于内源性和外源性因素的不同组合而获得。这些参数可用于根系统的表型分析。