Passion fruit (Passiflora edulis), a commercially vital tropical crop, faces flowering instability due to photoperiod-sensitive flowering patterns, particularly under the cloudy, rainy climates of subtropical regions. To mitigate floral suppression during unfavorable light conditions, this study implemented a dual-modality strategy combining 16 h daily supplementary lighting (460 nm blue + 630 nm red spectrum) and foliar application of a high-phosphorus-containing nutrient, the Plant-Prod (nitrogen–phosphorus–potassium = 10:52:10) grown in field ‘Qinmi No. 9’. The treatment significantly stimulated lateral branch formation, internode elongation, flower retention, stage IV flower bud development, and enhanced photosynthetic efficiency. Physiological analyses revealed that the treatment increased the net photosynthetic rate (Pn), reduced the intercellular carbon dioxide concentration (Ci), and enhanced stomatal conductance (Gs), indicating the improvement of carbon assimilation. Controlled seedling trials further confirmed these effects, with treated groups exhibiting accelerated lateral branching and stress resilience. This integrated approach, combining optimized supplemental lighting and precision phosphorus fertilization, offers a practical and scalable strategy to stabilize passion fruit yields in climate-variable regions, with immediate potential for commercial orchards and greenhouse production.

Background/Objectives: Floral bud morphogenesis is a critical developmental process determining yield potential in blueberry, yet the molecular regulatory mechanisms in leaves during this phase remain poorly understood. Methods: In this study, we employed a time-series transcriptomic approach to investigate leaf gene expression dynamics during floral bud morphogenesis in rabbiteye blueberry. Leaves were sampled at six time points spanning the critical developmental window from the cessation of summer shoot growth to bud swell and dormancy onset. Results: RNA-seq analysis generated 121.68 Gb of clean data, and weighted gene co-expression network analysis (WGCNA) identified four stage-specific modules (brown, red, blue, turquoise) significantly associated with distinct morphogenetic phases. The brown module (0–6W) was enriched in photosynthesis and hormone signaling pathways, while the red (9W) and blue (12W) modules featured protein processing, stress and hormone signaling, and carbohydrate metabolism. The turquoise module (15W) was dominated by carbon metabolism and flavonoid biosynthesis genes. Key flowering-related genes exhibited dynamic expression patterns: FT was specifically upregulated at the late stage (15W), AP2 genes peaked at mid-stage (9–12W), and COL9 showed early high expression (0–3W). Hormone-related gene analysis revealed extensive involvement of multiple pathways, with brassinosteroid (BR) signaling comprising the largest number of genes (101). Co-expression networks further identified hub genes, including FT, COL9, AP2, ERF1, SR160, LOX3-1, and transcription factor genes like MYB-related, as potential central regulators. Conclusions: Our findings demonstrate that blueberry leaves undergo a phased functional transition from a photosynthetic source to a hub for signal integration and metabolic support during floral bud morphogenesis, actively contributing to reproductive development through systemic signaling. This study provides novel insights into flowering regulation in woody perennials and establishes a foundation for marker-assisted breeding and cropping season management in blueberry.

Background/Objectives: Flower bud morphogenesis is a critical developmental phase during which blueberry transitions from vegetative to reproductive growth, yet the transcriptome dynamics and regulatory networks within buds during this process have not been systematically characterized. Methods: Terminal buds of the rabbiteye blueberry ‘Brightwell’ were sampled at six time points spanning from summer shoot cessation to bud swelling and dormancy entry. RNA sequencing, trend clustering, and Pearson correlation network analyses were performed to identify potentially important genes and regulatory relationships. Results: A total of 26,302 differentially expressed genes were identified, with a major transcriptomic shift at week 15. From four major expression trends, 1050 candidate genes were selected, including 176 flowering-related genes, 770 transcription factors, and 277 hormone-related genes. Photoperiod and vernalization pathway genes (COLs, VRN1, etc.) were predominantly down-regulated, whereas age pathway genes (SPLs) and MADS-box flower development genes (FULs, AP3, PI, and SEP2, etc.) were up-regulated. The floral integrators FT and SOC1 exhibited opposite expression dynamics: SOC1 was highly expressed during the early-to-mid stage, whereas FT peaked at the late stage, with the two showing opposing co-expression and correlation patterns. This suggests stage-specific divergence between the two integrators in coordinating flower bud differentiation and dormancy entry. Multiple hormone pathways (IAA, BR, JA, and SA, etc.) converged independently onto floral regulatory hubs through their biosynthesis/metabolism and signal transduction genes, with numerous transcription factors also involved. Conclusions: These findings provide a comprehensive view of bud transcriptome dynamics and propose a molecular regulatory framework integrating flowering signals, hormones, and transcriptional cascades, offering a theoretical foundation and gene resources for blueberry breeding.