盆栽番茄根系三维生长模型构建与实现

Three-dimensional growth modelling and realization for potted tomato root system

为探明负压地下灌溉条件下的盆栽番茄根系分布规律,通过试验测定不同生长时期的盆栽番茄根系三维空间坐标和生长参数.统计分析所测试验数据,明确了番茄各级根长生长函数、分根点分布及其侧生概率和侧生方向.基于番茄根系拓扑结构和实际生长规律,提出利用微分L系统构建番茄根系三维生长模型以描述盆栽番茄根系生长规律及其边界条件.文中以所构建的盆栽番茄根系三维生长模型为算法基础,利用OpenGL技术实现盆栽番茄根系三维生长可视化模拟系统,直观地再现了负压地下灌溉条件下盆栽番茄根系在不同生长时期的空间分布和生长情况.通过与试验数据对比分析,对于幼苗期的盆栽番茄根系分布平均模拟拟合度约为83%,而对于结果期的根系分布平均模拟拟合度约为91%.因此所建模型能够有效模拟盆栽番茄的根系生长情况.基于微分L系统的盆栽番茄根系三维生长模型可以表达不同生长时期番茄根系的形态特征和生长规律,为进一步研究土壤水分与根系生长的互作用奠定基础.

In order to explore the distribution characteristics of potted tomato root system under negative pressure underground irrigation,the three-dimensional spatial coordinates and growth parameters of tomato roots are measured at different growth stages. After analyzed the experimental data,the root growth function,lateral point distribution,lateral root birth probability and orientation are clarified.The differen-tial L-system is proposed to describe the tomato root growth model and boundary conditions based on the root topological pattern and actual growth situation. OpenGL technique is used to realize the three-dimensional visualization simulation system for potted tomato root growth,consequently,the root spatial distribution and growth state can be reconstructed intuitively under negative pressure underground irrigation. It is shown that the averaged fitness of root tip position distribution is about 83% inseedling stage but is approximate 91% in fruiting stage compared with experimental data. Hence the growth model generated can effectively simulate the growth of potted tomato root system. The differential L-system based model can exhibit the morphological characteristics and growth characteristics of potted tomato root system at different growth stages precisely. The results may form a base for forthcoming study on interaction between soil moisture and root system growth.