Light quality during night interruption affects morphogenesis and flowering in Petunia hybrida, a qualitative long day plant
We investigated the effects of light quality during night interruption (NI) on morphogenesis, flowering, and the transcription of photoreceptor genes in Petunia hybrida Hort. 'Easy Wave Pink' (a qualitative long day plant, LDP) Plants were grown in a closed type plant factory under a constant light intensity of 180 mmol*m 2*s 1 PPF provided by white (W) light emitting diodes (LEDs) under long day (LD, 16 h light/8 h dark) short day (SD, 10 h light/14 h dark) or SD conditions with a 4 h NI using green (NI G) blue (NI B) red (NI R) far red (NI Fr) or white (NI W) LEDs at an intensity of 10 mmol*m 2*s 1 PPF. Shoot length was greatest under NI Fr. Flowering was observed under LD, NI G, NI Fr, and NI W. The expression of photoreceptor genes was induced by NI. Specifically, phyA, phyB, and cry1 were more highly expressed under NI G, NI B, and NI R compared to LD and SD. These results suggest that morphogenesis, flowering, and transcriptional factors are strongly affected by light quality during NI.
Horticulture, Environment, and Biotechnology