Research Advances in the Regulation of Fruit Size: An Integrated Perspective of Genetic, Hormonal, Epigenetic, and Environmental Control
Key Laboratory of Cold Region Fruit Breeding and Cultivation, Mudanjiang Branch of Heilongjiang Academy of Agricultural Sciences, Mudanjiang 157000, China
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Authors to whom correspondence should be addressed.
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These authors contributed equally to this work.
Biology 2025, 14(12), 1643; https://doi.org/10.3390/biology14121643
Submission received: 22 October 2025
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Revised: 15 November 2025
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Accepted: 21 November 2025
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Published: 22 November 2025
Simple Summary
Fruit size, a vital agronomic trait, is orchestrated by interconnected genetic, physiological, and environmental pathways. Key genes and QTLs (e.g., fw2.2, fw3.2) modulate cell division and expansion, while phytohormones such as auxin, gibberellin, and cytokinin modulate developmental transitions. Transcription factors, including YABBY and WOX families, along with epigenetic mechanisms like DNA methylation, add further regulatory complexity. External factors-light, temperature, water, and nutrients-interact with cultivation practices to shape the final phenotype. Advances in multi-omics, gene editing, and AI are accelerating the dissection of these networks, offering promising strategies for targeted breeding of high-yield, quality fruit crops.
Abstract
Fruit size is a key economic trait in horticultural crops, determined by an integrated network of genetic, hormonal, epigenetic, and environmental factors. This review synthesizes recent advances in understanding this regulation. Genetically, key quantitative trait loci (QTLs) such as fw2.2, fw3.2, FAS, and LC control cell number and organ size. Hormones including auxin, gibberellin, cytokinin, and brassinosteroid regulate cell division and expansion. Transcription factors (e.g., YABBY, WOX families) and epigenetic mechanisms (DNA methylation, histone modifications, endoreduplication) provide additional regulatory layers. Environmental factors (light, temperature, water, nutrition) and cultivation practices (pruning, thinning) ultimately shape the final fruit phenotype. Emerging technologies like multi-omics, CRISPR-Cas9 gene editing, and artificial intelligence offer powerful tools for future research and molecular breeding, which aim to decode the complex regulatory network and enhance crop yield and quality.
