Tree Genetics and Molecular Breeding 2025, Vol.15, No.4, 147-153 http://genbreedpublisher.com/index.php/tgmb 149 4 Physiological Responses to Autumn Pruning 4.1 Redistribution of photosynthates and nutrient reserves Pruning in autumn can make the new shoots of loquats grow faster, with more leaves, thicker branches, stronger photosynthetic capacity of the tree and more nutrient accumulation. After pruning, the tree will transport more photosynthetic products and nutrients to the newly grown branches and flower buds, laying a solid foundation for flowering and fruiting in the following year. Su et al. (2024) found that strong new shoot cells divide more rapidly, which can promote the development of flowers and fruits, making the fruits larger and increasing their yield. 4.2 Hormonal regulation and shoot-flowering balance Pruning can alter the distribution and content of hormones in loquats, affecting the balance of branch growth and flower bud differentiation. It can inhibit some factors that hinder cell division, making cells more prone to proliferation and promoting the formation and development of flower buds (Su et al., 2024). Hormonal changes can also affect the ratio of flower buds to vegetative buds, making the flowering and fruiting in the following year more harmonious. 4.3 Influence on root activity and nutrient uptake efficiency After autumn pruning, the growth center of the tree will shift downward, which is conducive to root regeneration and enhanced activity. More active root systems can absorb water and nutrients more efficiently, which is very important for the growth of new shoots and flower buds and can also indirectly increase the yield of the following year (Cai et al., 2002). 5 Physiological Responses to N-K Ratio Regulation 5.1 Effects on floral induction, fruit set, and early fruit development Reasonable pruning methods, such as double-head pruning, can make new shoots grow faster, have more leaves and thicker branches. This will provide more nutrients and energy for flower bud differentiation and fruit development. Research has found that during the flower bud differentiation stage, the enhanced cell division ability significantly affects the size of flowers and fruits. Pruning can down-regulate cell division inhibitory genes (EjFWL1, EjFWL2), promote cell proliferation, and ultimately result in larger fruits and higher yields (Figure 1) (Su et al., 2024). In addition, appropriately thinning off some flower buds can also increase the fruit setting rate and make the fruit development more uniform. Maintaining a reasonable number of flower buds can result in a higher fruit setting rate and larger fruits (Nordi et al., 2025). 5.2 Interaction with water uptake and osmotic regulation in fruit cells Adjusting the ratio of nitrogen to potassium can affect the distribution of mineral elements in leaves and soil, thereby indirectly altering the regulation of water absorption and osmosis in fruit cells. When the supply of potassium in leaves is sufficient, the osmotic regulation ability of cells will be better, which can promote fruit enlargement and water accumulation, which will directly affect the size and texture of the fruit (Huang et al., 2021). 5.3 Changes in fruit quality attributes such as size, sweetness, and firmness Mineral nutrition, especially the balanced supply of nitrogen and potassium, has a significant impact on quality indicators such as single fruit weight, soluble solids (sweetness), and acidity. Studies show that the content of K and N in leaves is closely related to the weight and sweetness of the fruit. Reasonable adjustment of the N-K ratio can enhance the sweetness and flavor of fruits (Huang et al., 2021). Meanwhile, combined with reasonable flower thinning and pruning, it can also make the size and appearance of the fruit better and increase the commercial value (Nordi et al., 2025). 6 Integrated Effects of Pruning and N-K Regulation 6.1 Synergy in promoting balanced vegetative-reproductive growth Autumn pruning can make new shoots grow faster, with more leaves and thicker branches, providing more nutrients for flower bud differentiation and fruit development. Su et al. (2024) found that pruning methods such as double backcutting can promote cell division, inhibit the expression of some division inhibitors, and lead to better
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