Shift in the Light Quality of Night Interruption Affects Flowering and Morphogenesis of Petunia hybrida

Petunia hybrida Hort. “Easy Wave Pink”, a qualitative long-day plant (LDP), was investigated to study the effects of night interruption light (NIL) provided by light-emitting diodes (LEDs) quality shifting on morphogenesis, blooming, and transcription photoreceptor genes. Plants were grown in closed-type factory employing white (W) LEDs at an intensity 180 μmol·m−2·s−1 PPFD for short day (SD, 10 h light, 14 dark), long (LD, 16 8 or SD with 4 (NI) PPFD. The NIL shifted from one spectrum another after first 2 NI. Light treatments consisting all possible pairings W, far-red (Fr), red (R), blue (B) tested. LD referenced as control, while 12 NI involved altering LED qualities, follows: R B (NI-RB), (NI-BR), Fr (NI-FrR), (NI-RFr), (NI-FrB), (NI-BFr), W (NI-BW), (NI-WB), (NI-WFr), (NI-FrW), (NI-WR), (NI-RW). NI-RFr resulted longest shoots, NI-WR NI-RW shortest shoots. NI-WR, NI-RW, NI-BW, NI-WB, NI-RFr, NI-RB, NI-BR, exhibited flowering. High-level expressions genes confirmed NI-FrR, NI-BFr, treatments. Morphogenesis blooming both impacted photoperiod. had no flowering but second profound impact both.