The University of Queensland, School of Mathematics and Physics, Australia.
Ann Bot. 2011 Apr;107(5):747-64. doi: 10.1093/aob/mcq180. Epub 2010 Sep 20.
Functional-structural modelling can be used to increase our understanding of how different aspects of plant structure and function interact, identify knowledge gaps and guide priorities for future experimentation. By integrating existing knowledge of the different aspects of the kiwifruit (Actinidia deliciosa) vine's architecture and physiology, our aim is to develop conceptual and mathematical hypotheses on several of the vine's features: (a) plasticity of the vine's architecture; (b) effects of organ position within the canopy on its size; (c) effects of environment and horticultural management on shoot growth, light distribution and organ size; and (d) role of carbon reserves in early shoot growth.
Using the L-system modelling platform, a functional-structural plant model of a kiwifruit vine was created that integrates architectural development, mechanistic modelling of carbon transport and allocation, and environmental and management effects on vine and fruit growth. The branching pattern was captured at the individual shoot level by modelling axillary shoot development using a discrete-time Markov chain. An existing carbon transport resistance model was extended to account for several source/sink components of individual plant elements. A quasi-Monte Carlo path-tracing algorithm was used to estimate the absorbed irradiance of each leaf.
Several simulations were performed to illustrate the model's potential to reproduce the major features of the vine's behaviour. The model simulated vine growth responses that were qualitatively similar to those observed in experiments, including the plastic response of shoot growth to local carbon supply, the branching patterns of two Actinidia species, the effect of carbon limitation and topological distance on fruit size and the complex behaviour of sink competition for carbon.
The model is able to reproduce differences in vine and fruit growth arising from various experimental treatments. This implies it will be a valuable tool for refining our understanding of kiwifruit growth and for identifying strategies to improve production.
功能结构模型可以帮助我们深入了解植物结构和功能的不同方面如何相互作用，发现知识空白，并为未来的实验指明优先方向。通过整合猕猴桃藤结构和生理学不同方面的现有知识，我们旨在针对几个方面提出关于藤本植物的概念和数学假设：（a）藤本植物结构的可塑性；（b）冠层内器官位置对其大小的影响；（c）环境和园艺管理对新梢生长、光分布和器官大小的影响；（d）碳储量在新梢早期生长中的作用。
使用 L 系统建模平台，创建了一个猕猴桃藤的功能结构植物模型，该模型集成了结构发育、碳运输和分配的力学模型，以及环境和管理对藤本植物和果实生长的影响。通过使用离散时间马尔可夫链对腋芽发育进行建模，在单个新梢水平上捕获分枝模式。扩展了现有的碳运输阻力模型，以考虑个体植物元素的几个源/汇成分。使用拟蒙特卡罗路径追踪算法来估计每个叶片的吸收辐照度。
进行了多次模拟，以说明该模型再现藤本植物行为主要特征的潜力。该模型模拟的藤本植物生长反应与实验观察到的反应定性相似，包括新梢生长对局部碳供应的可塑性反应、两种猕猴桃物种的分枝模式、碳限制和拓扑距离对果实大小的影响以及碳源竞争的复杂行为。
该模型能够再现不同实验处理引起的藤本植物和果实生长的差异。这意味着它将成为一个宝贵的工具，可以帮助我们更好地理解猕猴桃的生长，并确定提高产量的策略。
