粗肋草品種之耐寒性與葉尖反捲原因之探討

Investigation of Chilling Tolerance and Bent-tip of Aglaonemas

本研究於人工氣候室探討溫度對台灣目前重要粗肋草品種葉片生長之影響，以期更瞭解品種之耐寒性與葉尖反捲彎勾之原因。於20／15℃處理五個月後，調查葉身有油浸斑點面積達25%之寒害葉數，其中白柄粗肋草（Aglaonemas commutatum‘Pseudobracteatum’）、黑美人粗肋草（A. commutatum‘Emerald Beauty’）、美麗粗肋草（A. commutatum var. elegans）與銀后粗肋草（Aglaonema‘Silver Queen’）有51.5%-67.8%之寒害葉數，而廣東粗肋草（A. modestum）僅有5.0%之寒害葉數。15／13℃處理五個月後，白柄粗肋草、黑美人粗肋草、銀后粗肋草與美麗粗肋草之所有展開葉片均受寒害，而廣東粗肋草僅有64.2%之寒害葉數。20／15℃與15／13℃不利各參試粗肋草葉片增生。參試品種於20-35℃處理七星期後，只有銀后粗肋草出現葉尖反捲彎勾症狀，且具此症狀之葉數隨溫度增高而增加。銀后粗肋草葉尖反捲彎勾部位比正常葉尖之氣孔密度高。在35／30℃下，銀后粗肋草之氣孔導度約為500-600µmol m-2 s-1，高於其它參試粗肋草之值約為100-350µmol m-2 s-1。 Effects of day/night temperature on leaf growth of Aglaonema species or cultivars were studied in phytotron conditions to have a better understanding of sensitivity to chilling injury and the causes of bent-tip. When subject to 20/15℃ for five months, Aglaonema commutatum ‘Pseudobracteatum’, A. commutatum ‘Emerald Beauty’, Aglaonema ‘Silver Queen’, and A. commutatum var. elegans had 51.5% to 67.8% leaves with chilling injury (＞1/4 damage leaf area), while A. modestum had only 5.0%. In the 15/13℃ treatment, chilling injury was expressed in 64.2% leaves of A. modestum, lower than the 100% in A. commutatum ‘Pseudobracteatum’, A. commutatum ‘Emerald Beauty’, Aglaonema ‘Silver Queen’, and A. commutatum var. elegans. In all genotypes tested, number of leaves was reduced with low temperatures of 20/15 and 15/13℃. Among the genotypes tested, the bent-tip syndrome appeared to be limited to Aglaonema ‘Silver Queen’. Number of bent-tip leaves increased with increasing temperature from 25/20℃ to 35/30℃. The portion of bent leaf tips showed a higher stomatal density than that of the normal tips. Aglaonema ‘Silver Queen’ treated at 35/30℃ showed stomatal conductivity of 500-600 µmol m-2 s-1, higher than those of 100-350 µmol m-2 s-1 in other genotypes tested.