Curd Initiation and Transformation in Tropical Cauliflower Cultivars under Different Temperature Treatments

Abstract

<jats:p>This study investigated the effects of different temperature treatments (18, 24, and 30 °C) on apex development in tropical cauliflower cultivars of varying maturity types. Two commercial cultivars, H-37 (early maturity) and H-80 (mid–late maturity), were used as the testing materials. ‘H-37’ reached the curd-initiation phase earlier than ‘H-80’ and showed superior growth during the curd’s initial development phase under all temperature treatments. Analysis of variance revealed significant effects regarding main temperature and cultivar as well as their interaction. ‘H-37’ at a temperature of 18 °C demonstrated the optimal transformation of apex development from the vegetative to reproductive stage. A temperature of 24 °C promoted the apex development of ‘H-37’ at the curd initial development phase. Gene expression analysis results indicated that the <jats:italic>BoFLC2</jats:italic> expression of ‘H-37’ was significantly down-regulated than that of ‘H-80’ after curd initiation and advanced growth. A temperature 30 °C accelerated the ending of juvenile stage and forward to curd initiation in ‘H-80’ and declined with temperature decreased. Moreover, expression of the <jats:italic>BoFLC2</jats:italic> transcript level of both tropical cauliflower cultivars nearly disappeared at the high temperature of 30 °C following curd initiation, suggesting that heat stress hinders curd formation. The results of this study also indicate that the number of leaves required to induce curd initiation is less than nine in tropical cauliflower at temperatures of 18 to 30 °C. In conclusion, under nonvernalized high temperatures, different cultivars of tropical cauliflower can initiate curd development but with a different pattern from those cultivars grown in temperate zones. This information may provide novel insights for cauliflower farmers or breeders in tropical regions.</jats:p>

Foliar Application of GA3 Stimulates Seed Production in Cauliflower

“…GA 3 application exogenously displayed a reduction in the time to flowering in cauliflower. However, the application of GA 3 during the early reproductive phase augmented bract development in curds of cauliflower [89,90]. In a study, the application of 50 ppm GA 3 ensured a minimum number of days required for 50% curd initiation and 50% marketable curd size in cauliflower [6].…”

Screening for Heat and Rain Tolerant Cultivars of Cauliflower for Cultivation in Monsoon Season in the Subtropical Region of Bhutan

“…For the conventional varieties of cauliflower, the optimum temperature for young seedlings is around 25℃ which at later growing stage drops to 20℃ for curd formation (Chatterjee & Mahanta, 2013;Kindo & Singh, 2018). However, if the temperature remains high (higher than required for curd formation), the plant will continue to remain in vegetative phase without forming any curd (Lin et al, 2019). In the present study, cauliflower cultivar Snow Mystique took 142 days for maturity after transplanting when planted on 18 August 2022 but it took only 77 days when transplanting was carried out on 30 th November 2022.…”