Allometric models for estimating the leaf area of lisianthus (Eustoma grandiflorum) using a non-destructive method

ABSTRACT Lisianthus (Eustoma grandiflorum) is a cut flower grown due to the wide diversity of colors and longevity in the post-harvest. The leaf area measurement is fundamental in plants because the leaves are directly related to several processes such as transpiration, radiation interception and CO2 fixation that enable the plant to grow. The objective of the work was to determine an allometric equation for estimating the leaf area of lisianthus from linear dimensions. 200 leaves were collected and the leaf length (L), leaf width (W), product between length and width (LW) and real leaf area (LA) were measured. The criteria for determining the best model were the highest determination coefficient (R2), Willmott's concordance index (d), lowest Akaike information criterion (AIC), root mean square error (RMSE) and BIAS index closest to zero. The most suitable model for estimating the leaf area of lisianthus is the linear ŷ = 1.387*LW.

摘要 洋桔梗（Eustoma grandiflorum）是一类因花色丰富多样、采后保鲜期长而被广泛种植的切花作物。植物叶面积测定是植物研究中的基础环节，叶片直接参与蒸腾作用、光能截获与二氧化碳固定等诸多助力植株生长的生理过程。本研究旨在构建基于叶片线性尺寸的异速生长方程，以估算洋桔梗的叶面积。研究共采集200片叶片，测定了叶长（L）、叶宽（W）、叶长宽乘积（LW）以及真实叶面积（LA）。模型优选标准为：最高的决定系数（R²）与威尔莫特一致性指数（Willmott's concordance index, d）、最低的赤池信息准则（Akaike information criterion, AIC）与均方根误差（root mean square error, RMSE），且偏差指数（BIAS index）最接近0。最终筛选得到的洋桔梗叶面积最优估算模型为线性模型：ŷ = 1.387×LW。