Flowering responses of Eremogone juncea (M. Bieb.) fenzl to photoperiod, chilling treatment, and cold storage

• Published in: Horticulture, environment and biotechnology 2022, Environment, and Biotechnology, 63(2), , pp.173-180
• Main Authors: Kang, Hyeonjeong, Im, Nam Hyun, An, Seong Kwang, Lee, Hyo Beom, Kim, Ki Sun
• Format: Article
• Language: English
• Subjects: Agriculture; Biomedical and Life Sciences; Chilling; Cold flow; Cold storage; Cold treatment; Cooling; Experiments; Flowering; Flowers; Life Sciences; Plant Breeding/Biotechnology; Plant Ecology; Plant Physiology; Plants (botany); Research Report; Seasons; 농학
• ISSN: 2211-3452; 2211-3460
• DOI: 10.1007/s13580-021-00395-2

This study was conducted to examine the flowering responses of Eremogone juncea to photoperiod (Experiment 1) and chilling treatment (Experiment 2). In addition, plants were subjected to cold storage following chilling treatment to extend the flowering season (Experiment 3). In Experiment 1, naturally chilled E. juncea plants were subjected to five different photoperiod conditions (9/15, 12/12, 14/10, 16/8, and 24/0 h). There were no differences in percent flowering among photoperiod treatment groups. Furthermore, these plants showed no significant differences among groups in the number of days to the first open flower. In Experiment 2, the plants were exposed to natural chilling for 0, 4, 8, or 12 weeks or artificial chilling at 5 °C for 0, 4, or 8 weeks. Percent flowering was less than 30% in the no-chilling treatment but increased with increasing chilling duration in both the natural and artificial chilling treatments. Days to the first open flower declined as the chilling duration increased. To quantify the chilling requirement, chill units (CUs) were calculated using a modified chilling hours model (MCHM) and a modified Utah model (MUM). To exceed 80% flowering, at least 1,854 CUs in MCHM or 1,889 CUs in MUM were required. In Experiment 3, naturally chilled E. juncea plants were stored for 0, 4, 8, or 12 weeks at 0 °C. Percent flowering significantly decreased under all cold storage treatments. However, cold storage treatment did not affect the number of days to visible bud or days to the first open flower. These results indicate that, although percent flowering was reduced by cold storage, the flowering season could be extended by storage treatment. In conclusion, E. juncea can be classified as a day-neutral plant with a chilling requirement for flowering. Moreover, artificial chilling treatment and cold storage can be used to advance or postpone the flowering season for year-round cultivation.