白鶴芋‘綠巨人’與黃金萬年竹在不同鐵濃度下之生長反應

Growth Response of Spathiphyllum 'Sensation' and Dracaena sanderiana 'Celica' to Iron Concentration

Spathiphyllum Schott 'Sensation' and Dracaena sanderiana Sander 'Celica' were grown for 345 days in 1/4 Hoagland solution containing either 0, 0.2, 0.4, 0.6, 7.8 or 15μM Fe-EDTA. For Spathiphyllum, shoot and root dry weights were reduced when plants were grown at 0μM Fe-EDTA, greatest at 0.4μM Fe-EDTA. Interveinal chlorosis was found only on younger leaves of plants at 0 or 0.2μM Fe-EDTA. For Dracaena sanderiana 'Celica', maximum shoot and root dry weights, and minimum leaf chlorosis occurred at 15μM Fe-EDTA. Spathiphyllum 'Sensation' root growth was stimulated at very low Fe concentrations, while that of Dracaena sanderiana 'Celica' was inhibited. Leaf Fe content of Spathiphyllum exhibited a quadratic response as Fe-EDTA increased, while leaf Fe content of Dracaena increased linearly with increasing Fe-EDTA from 0 to 15μM. 以含0, 0.2, 0.4, 0.6, 7.8或15μM Fe-EDTA之1／4 Hoagland修正水耕養液栽培白鶴芋‘綠巨人’與黃金萬年竹，經345天後調查並比較其生長。結果顯示：缺鐵會減少白鶴芋‘綠巨人’之枝條與根乾重；但Fe-EDTA增至0.4μM時，枝條與根乾重達最高。白鶴芋‘綠巨人’新葉葉脈間黃化之症狀，僅見於0或0.2μM Fe-EDTA處理者。另栽培在含15μM Fe-EDTA水耕液者，黃金萬年竹的枝條與根乾重達最高且黃化葉數最少。含低濃度Fe-EDTA之水耕液，增加白鶴芋‘綠巨人’的根乾重；但抑制黃金萬年竹之根生長。白鶴芋‘綠巨人’葉片鐵含量與水耕液之Fe-EDTA濃度呈曲線正關係；而黃金萬年竹的葉片鐵含量隨水耕液含Fe-EDTA濃度而直線上升。