溫度對仙客來生長開花與光合作用之影響

"Effects of Temperature on the Growth, Flowering, and Photosynthesis of Cyclamen Cultivars"

仙客來（Cyclamen persicum Mill.）為世界重要盆花，但於高溫下生長不良，故篩選耐熱品種為重要課題。本研究取迷你型、中花型及大花型仙客來共11個品種，分別置於20/15及30/25°C之人工氣候室並進行光合作用、生長與開花之比較。結果顯示各品種於30/25°C處理之單葉葉面積較大且葉色較淡、花朵數減少、植株較不緻密。除了30/25°C使迷你型'Silverado Scarlet'之淨光合作用速率顯著下降外，其餘品種於兩溫度處理之淨光合作用速率無顯著差異。迷你型仙客來於30/25°C處理之氣孔導度及蒸散速率均顯著較中花型及大花型高，葉片溫度也顯著較低。於30/25°C處理，迷你型'Smartiz Rose'、'Super Serie Verano Dark Violet'及'Metis Light Pink With Eye'之蒸散速率較高而降低葉溫，維持葉片、花芽分化能力及相對植株乾重與較佳的外觀品質，為相對耐熱品種；而迷你型'Silverado Scarlet'、大花型'Latina Success Deep Magenta'、'Halios HD Salmon'、'Sierra Synchro White'及'Snowridge Maxi Purple'於30/25°C處理之外觀品質、葉片及花芽分化能力差，花芽夭折率高，且相對植株乾重較低，為熱敏感品種。

"Cyclamen (Cyclamen persicum Mill.) is one of the most popular potted flowers worldwide but most cultivars grow poorly under high temperature conditions. It is crucial to screen heat-tolerant cultivars for growers in subtropical areas. This study aimed to determine the effects of temperature on the growth, flowering, and photosynthesis of eleven cyclamen cultivars grown at 20/15 and 30/25°C for seventy days. All cultivars at 30/25°C had bigger leaves, fewer flowers, and less compact than those at 20/15°C. For plants grown at 30/25°C, stomatal conductance and transpiration rates were higher and leaf temperature was lower in mini-flowered cultivars as compared with midi- or maxi-flowered cultivars. Except that mini 'Silverado Scarlet' at 30/25°C had lower net photosynthetic rate than that at 20/15°C, and net photosynthetic rate of other cultivars did not differ between 30/25 and 20/15°C treatments. Heat-tolerant mini 'Smartiz Rose', 'Super Serie Verano Dark Violet', and 'Metis Light Pink With Eye' at 30/25°C exhibited lower leaf temperature through higher transpiration rate and maintained acceptable quality, with only slightly reduced flower and leaf numbers. Heat-sensitive mini 'Silverado Scarlet', maxi 'Latina Success Deep Magenta', 'Halios HD Salmon', 'Sierra Synchro White', and 'Snowridge Maxi Purple' at 30/25°C had poor quality and reduced leaf and flower initiation rates, more blasted flowers, and lower relative plant dry weight than those at 20/15°C."