利用幾何形態學方法分析大岩桐花朵之形狀變異

Abstract

如何精確地分析花朵形狀變異，對於專門研究花朵形狀的生物學家，是一門非常重要的課題。本研究針對花朵的二維與三維影像進行形狀量化，並且分析花朵的形狀變異。研究的樣本是由野生型(兩側對稱)的花朵和栽培型(輻射對稱)的花朵雜交，得到形狀多樣的第二子代作為實驗對象，再由數位相機和微斷層掃描儀器分別獲取花朵的二維與三維影像。接著，利用幾何形態學方法，藉由特徵點選取來分析花朵的形狀變異。由主成份分析的結果，可以了解花朵形狀變化的主要趨勢。因此，由研究結果得知，本研究可以有效地量化並且分析花朵的形狀變異。

Quantifying floral shape in precision is crucial for studying the morphological variation of flowers. This work aims to measure the floral shape of Sinningia speciosa (Darwin’s Gloxinia) by using two-dimensional (2D) and three-dimensional (3D) floral images, and to examine the shape variation by using geometric morphometrics (GM). S. speciosa has two shape forms – bilateral symmetric wild type and radially symmetric peloria. In this work, the wild-type S. speciosa was crossed with the peloria to create the floral shape polymorphism. 2D and 3D floral images of second generation (F2) were obtained by using digital camera and micro-computed tomography (micro-CT), respectively. Their floral shapes were represented by a set of characteristic landmarks. GM was then applied to the landmarks to assess floral shape variations. ANOVA demonstrated the association between the floral shape variations and the SsCYC genotypes. It was shown that the proposed approach can adequately capture the shape variation of F2 flowers.