Structure Characteristics, Variation of Main Quantitative Traits, and Probability Grading of Chinese Olive (<i>Canarium album</i>) Seeds

In order to comprehensively describe and evaluate Chinese olive seeds, this study examined 33 varieties (strains) of Chinese olive seeds to address the limitations of previous research on quantitative trait variation and grading among Chinese olive seed varieties (strains). The research specifically focused on evaluating the morphological characteristics, seed locule structure, embryo composition, and phenotypic quantitative traits of Chinese olive seeds. The results indicated that Chinese olive seeds consisted of a core, seed coat, and embryo. Typically, the core contained two to four locules, with each locule containing zero to one embryos. Eight distinct structural variations were identified, with the number of locules per seed ranging from two to four and the number of embryos ranging from one to four. The most common structural types were ‘3-locule 1-embryo’ and ‘3-locule 2-embryo’, each occurring in 100% of the varieties (strains) studied. These two structural types also had a high average proportion within each variety (line), accounting for 50.17% and 42.06%, respectively. The average dimensions of a seed were 31.20 mm in length and 10.89 mm in width, with a shape index of 2.89 and weighing 1.55 g. These quantitative traits displayed significant variation, with the coefficient of variation being highest for single seed weight (19.35%) and lowest for seed length (9.39%). Normality tests revealed that seed width, seed length, and single seed weight followed a normal distribution. These traits were categorized into five levels based on specific points, with probabilities of occurrence approximately 10%, 20%, 40%, 20%, and 10%, respectively. The findings of this study are crucial for understanding and utilizing Chinese olive seed traits and provide valuable insights for the establishment of seed trait standards and data normalization.