Biogeographic Variability in Kernel Oil and Press Cake Content of Beauty Leaf Tree (Calophyllum inophyllum L.), as Determined by Chemical and Near-Infrared Spectroscopy Analysis

Abstract

The aim of this study was to evaluate biogeographic variability in the fruit, kernel, kernel-oil and press-cake contents of 50 accessions of the beauty leaf tree (C. inophyllum L.) collected from 19 locations spanning 4000 km along the eastern and northern coasts of Australia (Northern Territory and Queensland). Mature fallen fruits of C. inophyllum were collected from individual trees and stored in a shed for over a year. The fruits were cracked open to extract the kernels, and the kernels were crushed to 5–10 mm. NIR spectra of crushed kernels were collected using FT–NIR. Results of this study showed large variation between individual trees and the provenances for oil, resin and cake contents. Most of the C. inophyllum genotypes were separated based on their NIR fingerprint using PCA and PLS-DA. It was concluded that NIR spectroscopy not only aids in the screening of large numbers of genotypes, but it also allows the preservation of the tested seeds for further propagation. This feature will have the greatest advantage in plant breeding and commercial cultivation, as only the seeds that contain high oil content could be sown to help establish plantations with high oil-production capacity. Overall, it was concluded that the differences between provenances for oil, resin and cake contents can be predicted using NIR spectra. Furthermore, NIR spectroscopy can be used as a tool to define provenance variations in the kernel oil content of the beauty leaf tree.