Effect of photoperiod and temperature on inflorescence appearance and subsequent development towards flowering in onion raised from sets

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• 作者：Khalid Mahmud Khokhar ; P. Hadley ; S. Pearson
• 关键词：Inflorescence initiation ; Flowering ; Onion ; Photoperiod ; Temperature ; Seed production
• 刊名：Scientia Horticulturae
• 出版年：2007
• 出版时间：12 March 2007
• 年：2007
• 卷：112
• 期：1
• 页码：9-15
• 全文大小：385 K

文摘

The plants of two onion cultivars Sturon and Stuttgarter were raised from sets and placed in a growth room at 12 °C, a light flux density of 120 μmol m⁻² s⁻¹ and a 16 h photoperiod. Cultivar Stuttgarter took 195 days to initiate, whereas time for initiation in cv. Sturon was 201 days. After initiation the plants were transferred to wide range of photo-thermal regimes consisting of six set point temperatures (6, 10, 14, 18, 22 and 26 °C) and four photoperiods (8, 11, 14 and 17 h day⁻¹). An overall mean temperature for all developmental stages under each photo thermal combination was 12.2, 12.4, 15.9, 17.8, 23 and 24.4 °C. Time to inflorescence appearance, spathe opening and floret opening decreased linearly as temperature and photoperiod increased. At low to mild temperatures (12.2–17.8 °C), longer photoperiod enhanced florets per umbel, whereas at higher temperatures (23–24.4 °C), the floret number declined with lengthening photoperiods. As the photoperiod extension in each temperature advanced inflorescence appearance, spathe opening and floret opening and this would be beneficial in a programme to accelerate seed production in onion.