Red Light Night-Break at 660 nm Extends Autumn Flowering in Annona squamosa Through Shoot Senescence Delay and Phytohormone Remodeling Under Warm Temperature Dependence
Journal
Horticulturae
Journal Volume
12
Journal Issue
5
Start Page
617
ISSN
2311-7524
Date Issued
2026-05-15
Author(s)
Abstract
Extending the fruiting season of Annona squamosa L. requires overcoming autumn and winter flowering declines. This study investigates the efficacy of light-quality regulation technologies and their temperature dependence for floral induction. Field surveys initially identified temperature as the primary climatic factor governing flowering. Under suboptimal autumn temperatures, red light (R-660) night-break (NB) treatments significantly enhanced shoot growth and flowering compared to other light spectra. Transcriptomic analysis revealed 2027 upregulated and 341 downregulated transcripts consistently regulated by R-660, with significant enrichment in the plant hormone signal transduction pathway. Furthermore, R-660 upregulated cold response genes (e.g., CBFs, WRKYs, ERD7), which are associated with the maintenance of vegetative vigor under suboptimal autumn temperatures. However, mid-winter R-660 NB failed to induce flowering without supplemental greenhouse heating. Ultimately, warm ambient temperature is the absolute prerequisite for A. squamosa floral induction, with R-660 serving as a highly effective seasonal supplement to extend autumn flowering.
Subjects
Annona squamosa
flowering
LED
night-break
photoperiodism
red light
transcriptomics
Publisher
MDPI AG
Type
journal article