溫度對長實金柑生殖與營養生長之影響

Effects of Temperature on the Reproductive and Vegetative Growth of Oval Kumquat (Fortunella margarita Swingle)

本研究探討溫度對長實金柑（Fortunella margarita Swingle）生長之影響。2013年四月至九月間，將嫁接後兩年生長實金柑盆栽置於日/夜溫分別為30/25℃、25/20℃、20/15℃及15/13℃之自然光人工氣候室內，並以置於露天條件之相同條件盆栽作為對照。在30/25℃下之植株有最強的生長勢、開最多花，在處理後兩個月即開第一期花，隨後每次抽梢即伴隨開花。在25/20℃下的植株生長勢強，有最粗的的新生枝徑及最厚的葉片，但開花數少於前者。在20/15℃下的植株，新生枝梢少，且枝梢之生長由間歇性轉為連續性，有點類似徒長枝，同時在葉腋產生刺，而且不開花。在15/13℃下之植株，幾不生長，生長勢弱，新生枝條帶刺，葉片黃化，且不開花。試驗期間，露天的植株共生成三次梢，每次新梢發生均伴隨開花。顯示長實金柑在高溫條件下形成花芽，有別於其他柑橘類植物。

This study was conducted to investigate the effect of temperature on growth of oval kumquat (Fortunella margarita Swingle) plants. Two-year-old grafted and potted oval kumquat plants were kept in phytotrons under four day/night temperature conditions, that were 30/25℃, 25/20℃, 20/15℃ and 15/13℃, respectively. Meanwhile the plants in out-door were set as controls, from April to Sep. 2013. Plants in 30/25℃ condition had the most vigorous shoots growth and the largest number of flowers. The first flush of flowers appeared at two months after the experiment started, and then flowering occurred for every new flush afterward. In 25/20℃ condition, plants also grew vigorously, with the largest stem diameter and leaf thickness, but the number of flower was less than that of the plants under 30/25℃. In 20/15℃ condition, the shoot growth pattern changed from intermittent to durative, such as water sprouts, which with lots of short thorns on shoot but without flower formation. In 15/13℃ condition, plants were weak and the nodes bore short thorns, and leaves turned yellow with few new shoots and no flowers appeared. The plants growing in out-door had three flushes during the experimental period and each flush had flowers. The results indicated that the higher the temperature had the more flower bud formation. This phenomenon is unique for oval kumquat, which could not be found in most of the other citrus species.