2025 Volume 6 Issue 2 Pages 13-22
To discriminate between male-sterile and male-fertile Cryptomeria japonica (C. japonica) accurately, this study aimed to construct a discrimination model for identifying between male-fertility and male- sterility in C. japonica using fluorescence spectroscopy. The male strobili of the male-fertile and male- sterile C. japonica were divided into halves, and the internal fluorescence properties were measured by the excitation-emission matrix (EEM). Totally 10 data sets were derived from the EEM with different preprocessing methods, each of which was subjected to principal component analysis to construct a classification model based on the support vector machine (SVM). The data set with the highest F1 score (a harmonic mean of precision and recall) was the second derivative synchronous fluorescence spectra with Δλ = 80 nm and a window size of 11 nm, which shown a score of 98.5%. These spectra were deemed to be of high accuracy, as it was able to capture the fluorescence peaks that were specific to the male-fertile and male-sterile strobili. Additional data splitting analysis indicated that the kernel function k=1 in SVM was the optimum, resulting in a 100% precision to the test data. The results suggested the potential for utilizing fluorescence to distinguish between male-sterility and male-fertility in C. japonica.
