Differences in vernalisation responses in onion cultivars

• Published in: The journal of horticultural science & biotechnology Vol. 93; no. 3; pp. 316 - 322
• Main Authors: Fukuda, Machiko, Yanai, Yosuke, Nakano, Yuka, Higashide, Tadahisa
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 04.05.2018
• Subjects: accumulation period; Allium cepa; effective temperature; vernalisation model
• ISSN: 1462-0316; 2380-4084
• DOI: 10.1080/14620316.2017.1372111

Onions normally form bulbs in the first year of growth; however, exposure to low temperatures can induce flowering (vernalisation) before bulbs are produced. Based on the cultivation data of onions grown in Japan, we evaluated and validated a reported model describing the onion vernalisation response. The observed bolting rates of 'Sapporoki', which was used in the construction of a previous model, were a good fit to the model, whereas, the bolting rates of one of the overwinter-type cultivars, 'Momiji No.3ʹ, were lower than the predicted value. The difference between the predicted and observed bolting rates in 'Momiji No.3ʹ was caused by a larger VD 0.5 , the coefficient in vernalisation response models that represents the time point when half of the plants have bolted. Overwinter-type and/or bolting resistant cultivars can have parameters that indicate a further vernalisation requirement for bolting. The parameters in our model can be customised to the cultivar being investigated, and our study suggests the viability of modelling onion bolting by using air temperature.