Effects of Different Pollination Treatments on the Appearance and Cell Development Characteristics of Blueberry Fruit

The method of pollination significantly affects the growth and development of blueberry fruit. However, there remains a deficiency in systematic research regarding the impact of various pollination treatments on the cellular structure of blueberries. In the present study, a cross-pollination experiment was conducted on the blueberry varieties 'Reka', with the objective of comparing the characteristics of blueberry fruit cells under different pollination treatments. The results showed that different pollen sources had certain effects on the pedicel marks, calyx width and seed number of blueberry fruit. Simultaneously, various pollination treatments significantly affected both the transverse and longitudinal diameters as well as the individual fruit weight of the fruits. However, no significant differences were noted in the fruit shape index across the various pollination treatments. Within the internal cellular tissue of each treated fruit, certain indicators exhibited distinct variances. In the cell height of the inner region of the mesocarp, all cross-pollination treatments were significantly higher than self-pollination. The fruit of 'Northland' and 'Blomidon' were significantly lower than self-pollination in the number of cells in the outer area of the mesocarp. These effects lead to differences in cell arrangement and spatial distribution, resulting in differences in the correlation between cell indexes and fruit morphological indexes among different treatments. In the 'Reka' self-pollination treatment, the endocarp width was significantly negatively correlated with the fruit weight (p < 0.05), while the correlation in the other four treatments showed an upward trend, showing a positive correlation. This study comprehensively examined the formation of fruit cells under cross-pollination at the cellular level, thereby providing a cytological basis for understanding the development of blueberry fruit.