玫瑰‘紅隊長’之扦插繁殖及栽培管理

Abstract

玫瑰(Rosa hybrida)為薔薇科(Rosaceae)之重要花卉作物，其中‘Red Captain’被認為是對臺灣物候適應性較佳的景觀或盆花品種；但缺乏科學文獻報導。本研究探討玫瑰‘Red Captain’扦插繁殖及栽培管理對其生長、光合作用與開花之影響，期望建立有效之扦插繁殖及栽培管理之資訊，以供生產與景觀布置參考。 剪取玫瑰‘Red Captain’帶花芽可見之枝條，將花芽剪去後選取花下第1-2節、3-4節、5-6節及7-8節插穗，結果顯示7-8節插穗之存活率顯著低於其他處理，1-2節插穗之地上部長度明顯縮短，地上部乾重最低，最大根長、發根數及地下部乾重以3-4節為最高。另取花下第1節、1-2節、1-3節及1-4節插穗，結果顯示四種節數之插穗地上部長度及地上部乾重隨節數增加而上升，而根系發育及最大根長度以1-3節及1-4節插穗表現最好，發根數量及根乾重以1-4節之插穗最多。 以WET Sensor測定介質體積含水量(volumetric water content, VWC)，設計淹水(70% VWC)、經常濕潤(40% VWC)、乾旱(20% VWC)、乾溼交替(20/55% VWC) 之處理。結果顯示玫瑰‘Red Captain’之植株外觀以40% VWC及20/55% VWC處理較佳；20% VWC處理之淨光合作用速率等生理及生長指標皆最低，顯示玫瑰‘Red Captain’為稍耐濕，但不耐旱之植物。 以溫積值模型評估花朵發育速率，結果顯示玫瑰‘Red Captain’ 從花芽可見到開花之基礎溫度為5 °C，花朵發育所需之溫積值為500 °Cd。植株外觀表現以25/20 °C處理較佳；高溫35/30° C及30/25 °C處理之花芽可見天數、花朵壽命、光合作用等生長指標均顯著低於其他處理；低溫15/13 ℃處理雖葉片厚實且濃綠，但側枝長明顯縮短且花辦數較少， 20/15 ℃處理雖具較長之側枝長度及最大之花朵直徑，然其花朵較垂，降低觀賞價值。 將玫瑰‘Red Captain’植株修剪至 8、16、24 cm (介質表面算起至植株最高處)及未經修剪之控制組，株高約為70 cm。結果顯示以修剪至8 cm處理之植株較為瘦弱，淨光合作用速率等生理及生長指標皆最低；整體外觀表現以修剪至16 cm及修剪至24 cm處理較為茂密、緊湊；而未經修剪之處理葉片有明顯黃化徵狀，且沒有側枝產生，花朵數較少且花朵直徑也顯著較小。 將玫瑰‘Red Captain’枝條第4、6及8節(介質表面算起)處剪除，結果顯示以修剪至4節之枯枝率較為高，而葉綠素計讀值、開花率、側枝長度、莖徑及淨光合作用速率等生理及生長指標皆最低；整體生長表現以修剪至8節處理者最佳，且花芽可見天數顯著低於其他處理。 將玫瑰‘Red Captain’ 栽培於每日平均正午光強度為647.9 µmol·m-2·s-1 PPFD平均溫度為28.2°C時，淨光合作用速率隨光度增加而上升，光飽和點約為800 µmol·m-2·s-1 PPFD，此時淨光合作用速率為16.4 μmol·CO2·m-2·s-1。其光反應曲線顯示其光補償點為21.8 µmol·m-2·s-1。二氧化碳濃度自0提升至800 μmol CO2·mol-1，使淨光合作用速率隨之增加，二氧化碳濃度在700 μmol CO2·mol-1達最高，此時之淨光合作用速率為30.8 μmol·CO2·m-2·s-1，且細胞間隙二氧化碳濃度亦提升。當VPD固定為 1.2±0.1 kPa時，玫瑰‘Red Captain’光合作用適溫為30 ℃。VPD在0.85 至2.22 kPa區間，玫瑰‘Red Captain’ 之淨光合作用速率於VPD為1.35 kPa下最佳。

Rose (Rosa hybrida) is an important flower crop. Rose ‘Red Captain’ has been considered to suit for subtropical environmental conditions in Taiwan. However, information on the related cultivation is presently limited. This study investigates the effects of cutting propagation and cultivation management on the growth, photosynthesis, and flowering of the rose ‘Red Captain’. The aim is to establish effective information on cutting propagation and cultivation management to refer to production and landscape arrangement. Taking cuttings of the rose ‘Red Captain’ with visible flower buds, and after removing the flower buds, cuttings from the 1st-2nd, 3rd-4th, 5th-6th, and 7th-8th nodes below the flower were selected. The results showed that the survival rate of cuttings from the 7th-8th nodes was significantly lower than the other treatments. The shoot length of cuttings from the 1st-2nd nodes was noticeably shorter, with the lowest shoot dry weight, while the longest root length, number of roots, and root dry weight were highest in cuttings from the 3rd-4th nodes. Additionally, cuttings were taken from the 1st node, 1st-2nd nodes, 1st-3rd nodes, and 1st-4th nodes below the flower. The results indicated that the shoot length and shoot dry weight of the cuttings increased with the number of nodes, with the best root development and maximum root length observed in cuttings from the 1st-3rd and 1st-4th nodes. The highest number of roots and root dry weight were found in cuttings from the 1st-4th nodes. Using a WET Sensor to measure the volumetric water content (VWC) of the medium, treatments were designed as follows: flooding (70% VWC), constantly moist (40% VWC), drought (20% VWC), and alternating dry and wet (20/55% VWC). The results showed that plants at 40% VWC and 20/55% VWC had better growth performance. The 20% VWC treatment resulted in the lowest net photosynthetic rate and other physiological and growth indicators, indicating that the rose ‘Red Captain’ is moderately tolerant to moisture but not drought tolerant. Using a thermal time model to evaluate the flower development rate, the results showed that the base temperature for rose ‘Red Captain’ from flower bud visibility to flowering is 5 °C, and the thermal time for flower development is 500 °Cd. Plants at 25/20°C had better growth performance. High temperature treatments of 35/30 °C and 30/25 °C resulted in significantly lower flower bud visibility days, flower longevity, photosynthesis, and other growth indicators compared to other treatments. Although the 15/13 °C treatment produced thick and dark green leaves, the length of the lateral shoot was significantly shorter, and the number of petals was fewer. The 20/15 °C treatment resulted in longer lateral shoot length and the largest flower diameter, but the flowers tended to droop, reducing their ornamental value. The rose ‘Red Captain’ were pruned to heights of 8 cm, 16 cm, 24 cm (measured from the substrate surface to the highest point of the plant), and unpruned treatment. The results showed that plants pruned to 8 cm were weaker, with the lowest net photosynthetic rate and other physiological and growth indicators. Plants pruned to 16 cm and 24 cm had denser and more compact appearance. Unpruned plants exhibited chlorotic leaves , no lateral shoot growth, fewer flowers, and smaller flower diameters significantly. The rose ‘Red Captain’ was pruned at the 4th, 6th, and 8th nodes (measured from the substrate surface). The results showed that pruning at the 4th node resulted in a higher rate of dead branches, and the SPAD-502 value, flowering rate, lateral shoot length, stem diameter, and net photosynthetic rate were all the lowest among the treatments. Plants pruned to 8th node had better growth performance, with a significantly lower flower bud visibility days compared to the other treatments. The net photosynthetic rate increased with rising light intensity. The net photosynthetic rate reached saturation at light intensity 800 μmol·CO2·m-2·s-1 , with a net photosynthetic rate of 16.4 μmol·CO2·m-2·s-1. Light compensation point was estimated as 21.8 μmol·CO2·m-2·s-1. As the carbon dioxide concentration increase from 0 to 800 μmol CO2·mol-1,the net photosynthetic rate and intercellular carbon dioxide concentration increased. The concentration of carbon dioxide reached a maximum of 700 μmol·CO2·m-2·s-1, with a net photosynthesis rate of 30.8 μmol·CO2·m-2·s-1. When the vapor pressure deficit (VPD) was fixed at 1.2±0.1 kPa, the optimal temperature for rose ‘Red Captain’ was 30°C. Within the VPD range of 0.85 to 2.22 kPa, the optimal VPD for photosynthesis was 1.35 kPa.