Phenotypic Characteristics of Quantitative Traits in an Everbearing Strawberry <i>F₁</i> Population

Cultivated strawberry (Fragaria ananassa Duch.) is a globally important fruit crop with annual production exceeding 9 million tonnes worldwide (Kouloumprouka Zacharaki et al. 2024).In Korea, most commercial production relies on June-bearing cultivars grown in greenhouses from winter to spring.Since the early 2000s, however, growers in high-altitude regions above 800 m have adopted everbearing cultivars that initiate flowers under long-day, high-temperature conditions.This enables fruit harvest during the summer-fall period when June-bearing strawberries are unavailable and provides a premium fresh product in domestic and export markets.Flowering physiology differs fundamentally between June-bearing and everbearing cultivars.June-bearing types initiate flower buds under short days, whereas everbearing types maintain flowering under long days and warm temperatures.The major locus PFRU interacts with FaTFL1, a floral repressor integrating photoperiod and temperature signals (Hytnen et al. 2020;Rantanen et al. 2015).While flowering regulation has been studied extensively in June-bearing cultivars, research focusing on everbearing cultivars remains relatively limited, making it more difficult to improve yield stability and fruit quality in breeding programs.