Variation in Fruit Traits and Seed Nutrient Compositions of Wild <i>Camellia oleifera</i>: Implications for <i>Camellia oleifera</i> Domestication

<i>Camellia oleifera</i> is a woody oil crop with the highest oil yield and the largest cultivation area in China, and <i>C. oleifera</i> seed oil is a high-quality edible oil recommended by the Food and Agriculture Organization of the United Nations. The objectives of this study were to investigate the variation in fruit yield traits and seed chemical compositions of wild <i>C. oleifera</i> in China and to identify the differences between wild <i>C. oleifera</i> and cultivated varieties. In this study, we collected wild <i>C. oleifera</i> samples from 13 sites covering the main distribution areas of wild <i>C. oleifera</i> to comprehensively evaluate 25 quantitative traits of wild <i>C. oleifera</i> fruit and seed chemical compositions and collected data of 10 quantitative traits from 434 cultivated varieties for a comparative analysis of the differences between wild and cultivars. The results showed that the coefficients of variation of the 25 quantitative traits of wild <i>C. oleifera</i> ranged from 2.605% to 156.641%, with an average of 38.569%. The phenotypic differentiation coefficients ranged from 25.003% to 99.911%, with an average of 77.894%. The Shannon–Wiener index (H’) ranged from 0.195 to 1.681. Based on the results of principal component analysis (PCA) and phenotypic differentiation coefficients, 10 traits differed significantly between wild <i>C. oleifera</i> and cultivated varieties, while the differentiation coefficients (V_ST) for fresh fruit weight, oleic acid, unsaturated fatty acids, stearic acid, and saturated fatty acids were more than 95%, of which fresh fruit weight and oleic acid content were potential domestication traits of <i>C. oleifera</i>. The results of this study can contribute to the efficient excavation and utilization of wild <i>C. oleifera</i> genetic resources for <i>C. oleifera</i> breeding.