氣溫與根溫對檬果開花及葉片中碳水化合物與無機要素含量之影響

Effects of Air and Root Temperatures on Flowering and Leaf Carbohydrate and Mineral Nutrient Content of 'Irwin' Mango (Mangifera indica L.)

2年生盆栽愛文檬果以2種氣溫（30／25°C及20／15°C）與3種根溫（30／25°C，25／20°C，20／15°C）處理，在高氣溫下開花之植株，花序上之小花數遠較在低氣溫下少，在低氣溫下（20／15°C），20／15°C、24／19°C及28／24°C根溫之植株的小花數分別為在高氣溫（30／25°C），相同根溫下之植株的4.5、5及1.5倍。以完全花比例而論，25／20°C根溫下之完全花比例最高，而以30／25°C氣溫20／15°C根溫下完全花比例最低，顯示25／20°C根溫下之檬果開花品質最佳，而在高氣溫偏低之根溫下最為不利。由葉片分析資料顯示，低根溫及低氣溫下葉片之碳水化合物較高，而無機要素之含量則隨溫度下降而減少，尤其以微量要素最為明顯。顯示在不同之氣溫與根溫條件下，氣溫對檬果葉片中碳水化合物蓄積之影響較大，而根溫則對無機要素之含量影響較大。綜合以上之結果發現，小花數及花期與葉片中碳水化合物含量較為密切，而無機要素則與完全花比例略有關係。

Potted mango of two years old, were treated with two air temperatures (30/25°C, day and night temperature) and three root temperatures (30/25°C, 25/20°C and 20/15°C). Day and night root temperature of 25/20°C favored the formation of hermaphrodite flowers, despite of air temperature. The combination of higher air (30/25°C) and lower root temperature (20/15°C) resulted in less hermaphrodite flowers. The results of mineral nutrients and carbohydrates analyses indicated that low air and low root temperatures led to a higher carbohydrates and lower mineral nutrient contents in the leaves, especially those of micro-nutrients. As a general rule, the treatments of different air temperature affected more upon the accumulation of carbohydrates, while root temperature affected more upon mineral contents in the leaves. The results indicated that the number of flowers per panicle and the earliness of flowering is possitively correlated with carbohydrates contents in the leaves, while the changes of mineral nutrient contents in the leaves may affect to the formation of hermaphrodite flowers.