觀賞植物耐陰性指標與光適應之研究

Abstract

本試驗以常見30種觀賞植物為主，調查在人工環境光強度150 μmol•m-2•s-1，氣溫32±0.5℃環境下，放置一小時後用紅外線熱像儀調查觀賞植物葉溫差值ΔT(℃)，以及利用GFS-3000調查在光強度400、800及1200 μmol•m-2•s-1下植物的光合作用潛力值。結果發現。30種觀賞植物，屬於陽性植物有17種，葉溫差範圍為-3.1℃至-0.47℃，最低依次為新幾內亞鳳仙花(Impatiens hawkeri)的 -3.03℃、五彩石竹(Dianthus barbatus)的 -3.07℃、雞冠花(Celosia cristata)的 -3.10℃；而屬於陰性植物有13種，葉溫差範圍為-0.16℃至4.95℃，最高依次為密葉蔓綠絨(Philodendron ‘Temptation II’)的4.95℃、萊姆黃金葛(Scindapsus aureum ‘All Gold’)的2.22℃、娃娃朱蕉(Cordyline terminalis ‘Dolly’)的1.74℃，是個簡單且迅速的區分兩類植物之調查方法。然而，此方法需特別注意葉片角度與水分狀態，否則會產生很大的誤差值。在光合作用潛力方面，陰性植物再3-7 μmol CO2•m-2•s-1之間，最低為銀后粗肋草(Aglaonema ‘Silver Queen’)的 3.0 μmol CO2•m-2•s-1、萊姆黃金葛(Scindapsus aureum ‘All Gold’)的 4.0 μmol CO2•m-2•s-1、阿波羅千年木(Dracaena deremensis ‘Compacta’)的 4.4 μmol CO2•m-2•s-1；陽性植物光合作用潛力在7-12 μmol CO2•m-2•s-1之間，最高依次為馬櫻丹(Lantana camara)的 10.7 μmol CO2•m-2•s-1、繁星花(Pentas lanceolata)的 11.6 μmol CO2•m-2•s-1、檸檬香蜂草(Melissa officinalis)的 11.8 μmol CO2•m-2•s-1，兩種調查方法與光補償點都具有高度相關性(R=0.8399與R=0.8990)，但調查方法相較於傳統的光補償點迅速，因此可作為快速評估植物光適應性的方法。 光馴化主要為植物自行調整光補償點(light compensation point, LCP)的特性，這種能力各種屬的品種間差異頗大。利用一串紅(Salvia splendens ‘Vista Red’)、粗肋草(Aglaonema ‘Silver Queen’)、新幾內亞鳳仙花(Impatiens hawkeri ‘Divine Blue Pearl’)與山菜豆(Radermachera sinica)，模擬植物從原生環境，經過3、7、10或14天短時間馴化，後再移至室內環境14或21天，調查其生理與外觀品質，並以外觀品質為基準，找出非破壞性判斷馴化狀況的調查方法。結果顯示，植物在不同光強度下，會改變外觀及生理狀況來適應環境，透過本次試驗得知植物在生產後移至室內環境前，以100 μmol•m-2•s-1馴化7-10天或許可後續提高觀賞品質，但會因植物種類不同有些差異，且可以葉溫差作為調查馴化狀況的非破壞性指標。

This trial inspected the temperature difference of leaves after exposed to light intensity 150 μmol•m-2•s-1 and 32±0.5℃ degrees in 30 common ornamental plants and used GFS-3000 to determine the photosynthesis potential under light intensity 400, 800, 1200 μmol•m-2•s-1. The results showed that the temperature changes of sun plants and shade plants are -3.1℃ to -0.47℃ and -0.16℃ to 4.95℃, respectively. It is a very simple and fast way but the angle of the leaf and moisture condition should be tended to avoid large deviation. The photosynthesis potential values of shade and sun plant are 3-7 μmol CO2•m-2•s-1and 7-12 μmol CO2•m-2•s-1, respectively. This survey method is more rapid than the conventional method; therefore, it can be used as the approach to determine the light requirements of plants. The light intensity at the production phase has huge impacts on the quality of ornamental plants. Most of the production of ornamental plants in Taiwan use shade cultivation with light intensity of 100 μmol•m-2•s-1 and 200 μmol•m-2•s-1, therefore being more suitable for common low light intensity environment of indoor. However, the light saturation points of ornamental plants on the market right now (most>400 μmol•m-2•s-1) are higher than the current production light intensity. To ensure the production quality, industry reduced the light intensity at the production phase to prolong the production time. But a few kinds of plants can grow under the full light condition and quickly showed the etiolation and defoliation phenomenon if moved into indoor environment and lower the ornamental life span. Therefore, before the sales, at least 3 to 6 months of acclimation treatment is essential for plants to adapt to weak light before the sale to preserve the reputation. The light acclimation is that plants can adjust their LCP on their own. This ability is very different from each species. In this chapter, we use the Salvia splendens ‘Vista Red’, Aglaonema ‘Silver Queen’, Impatiens hawkeri ‘Divine Blue Pearl’, Radermachera sinica to mimic the situation that plants were moved from native growing environment to indoors for 2 to 3 weeks after the 3, 7, 10 or 14-days light acclimation treatment to access the conditions of acclimation by observing the exterior and physiological quality of plants in non-destructive survey methods. Results indicated that plants altered their exterior and physiological to adapt to different environments. Based on the outcomes of this trial, we can know that the ornamental quality can be improved by 100 μmol•m-2•s-1 acclimation for 7-10 days before being moved into the low light condition but the effects are various from each species and the temperature difference can be used as the non-destructive indicators to investigate the acclimation conditions.