Please use this identifier to cite or link to this item:
Flowering Inhibition in Phalaenopsis
|Advisor:||張耀乾(Yao-Chien Alex Chang)|
Phalaenopsis,light quality,flowering inhibition,shade net,root temperature,
|Publication Year :||2016|
大白花蝴蝶蘭(Phalaenopsis Sogo Yukidian ‘V3’)經6週黑暗處理後，葉片葡萄糖和果糖濃度分別下降22.6%、34.1%，而蔗糖與澱粉濃度則大幅減少66.1%、71.5%。顯示葡萄糖與果糖應是維持蝴蝶蘭基本生理反應的醣類，因此即便經歷長時間黑暗逆境，其濃度變動較蔗糖與澱粉緩和。不同葉齡間，第1片葉之葡萄糖與果糖濃度為第3、5片葉的1.5至3.1倍，但經過4週以上之黑暗處理後，濃度降至與第3、5片葉無顯著差異。催花前的黑暗處理對到花日數、花梗長、第一朵花徑、花序壽命等開花參數沒有影響，但在植株出庫時出現新葉白化及落葉之現象，並使植體內的碳水化合物濃度降低，故黑暗處理可能不是理想的抑梗方法。
在藍色遮陰網或綠色遮陰網栽培下，大白花蝴蝶蘭(Phal. Sogo Yukidian ‘V3’)中苗以及黃花蝴蝶蘭(Phal. Sogo Allen ‘Sogo F2059’)大苗的淨光合作用速率下降，根部鮮、乾重較低。栽培於紅色遮陰網下的植株，葉色偏黃綠色，其變化與光質試驗的紅光處理非常類似。變更至有色遮陰網下的栽培環境對蝴蝶蘭而言是個逆境，其Fv/Fm下降應是保護PS II所進行的可逆性調節，所以後期適應環境後Fv/Fm隨即回升至接近初始值。在有色(紅色、藍色、綠色)遮陰網下栽培，或先栽培於黑色遮陰網再移至有色遮陰網的蝴蝶蘭‘V3’中苗，相較於全程栽培於黑色遮陰網的植株，有較高的抽梗率，應屬逆境誘導之開花反應。
對白花蝴蝶蘭(Phal. amabilis)以噴施或澆灌的方式施用ABA無法抑制抽梗，僅澆灌高濃度1 mM之ABA處理，使抽梗延遲2至3天，因此以噴施或澆灌的方法施用ABA並非有效的抑梗方法。蝴蝶蘭施用濃度125至1000 mg·L-1的益收生長素(Ethephon)，對抑制抽梗沒有幫助，且造成落葉。提高蝴蝶蘭的根溫無法抑制抽梗，反而使其提早抽梗，因此蝴蝶蘭感受低溫的部位主要應是在地上部，而非地下部。
大白花蝴蝶蘭(Phal. Sogo Yukidian ‘V3’)經週期性低溫/高溫處理，隨接受高溫的頻率增加，抽梗率隨之降低，當接受的高溫比率超過2/3時(1天低溫2天高溫)，可完全抑制抽梗。在高溫比例不超過1/3的情況下，增加高溫比率可提早蝴蝶蘭開花，且不影響花朵數、花梗長。因此適當的週期性低溫/高溫的環境可節省催花或抑梗作用的能源使用。
Temperature is the main factor of regulating the flowering of Phalaenopsis. Inhibiting spiking is thus crucial to produce high quality semi-mature or mature plants. This research investigated the effects of dark, light quality, plant growth regulators, and intermittent cool temperature on the flowering of Phalaenopsis, in order to find alternative methods for flowering regulation.
After 6 weeks of dark treatment, leaf glucose (Glu.) and fructose (Fru.) concentrations of Phalaenopsis Sogo Yukidian ‘V3’ declined respectively 22.6% and 34.1%, while sucrose and starch concentrations decreased 66.1% and 71.5%, respectively. Results indicated that Glu. and Fru. might be the crucial saccharides of maintaining basic physiologic metabolism in Phalaenopsis. Thus, even the plants experienced a long tern darkness, the changes of Glu. and Fru. were assuasive relatively. The top-most newly developing (the first) leaf had 1.5 to 3.1 times higher glucose and fructose concentrations than those of the third and fifth leaves. But no significant difference in glucose and fructose concentrations was observed between leaf positions after over 4 weeks of dark treatment. Dark tretments, prior to flower forcing, did not affect spiking rate, spike diameter, flower diameter, time to spiking, and time to flowering. However, dark treatments caused etiolated new leaf, dropped lower leaves, and declined carbohydrate concentration, indicating dark treatment might not be an ideal method for inhibiting the spiking of Phalaenopsis.
Five miniature Phalaenopsis cultivars were treated with white, red (R), blue (B), 7R2B, 5R4B, 2R7B LEDs, and dark. Plants after R treatment showed lower SPAD and a* values, and higher L* and b* values, representing a bright yellow-green color. All but dark and R treatments had decreased Fv/Fm at the beginning, but recovered grandually and then approached the initial value at later stages of the experiment. R treated plants had lower Fv/Fm value throughout the experiment. R treated plants had scattered inflorescences due to increased spike length and length between flowers. Light quality treatments did not promote or inhibit spiking in tested Phalaenopsis cultivars, nor affect days to spiking, spike count, days to flowering, and flower count.
Phalaenopsis Sogo Yukidian ‘V3’ and Phal. Sogo Allen ‘Sogo F2059’ were grown under black, red, blue, and green shade nets. Plants had decreased net CO2 uptake, root fresh and dry weights when grown under blue and green shade nets. Plants grown under red shade net had yellow-green leaves similar to the above-described R LED treatment in the light quality experiment. Transition cultivation to colored shade nets (red, blue, or green) was a stress for Phalaenopsis, as indicated by the reduced Fv/Fm value. However, Fv/Fm rose and recovered to the initial value after the plants had adapted to the environment, demonstrating that was a reversible regulation for protecting the PS II. Phalaenopsis Sogo Yukidian ‘V3’ plants grown under colored shade nets or the plants transferred from black shade net to colored shade nets had higher spiking ratio than those continuously grown under the black shade net; it seemed to be a stress-induced flowering reaction.
Spraying or drenching Phal. amabilis with abscisic acid (ABA) did not inhibit its spiking, although drenching with 1 mM ABA slightly delayed spiking for 2 to 3 days. Therefore, spraying and drenching ABA were both ineffective methods to inhibit Phalaenopsis spiking. Spraying ethephon at 125 to 1000 mg·L-1 was either not effective to inhibit Phalaenopsis spiking, but caused leaf abscission. Rising the root temperature of Phalaenopsis did not inhibit but advance spiking. Therefore, Phalaenopsis persceives low temperature to spike by shoot but not root.
After the cyclic low/high temperature treatment, results indicated spiking ratio decreased as high temperature ratio increased. Spiking was completely inhibited when the high temperature exceeded a two third ratio (i.e., 1 day in low temperature and 2 days in high temperature). Spiked plants flowered earlier when the high temperature did not exceed an one third ratio, and no difference in flower count and spike length were found. Therefore, energy saving when forcing Phalaenopsis in summer might be achieved by using proper cyclic low/high temperature for forcing or inhibiting the flowering of Phalaenopsis.
|Appears in Collections:||園藝暨景觀學系|
Files in This Item:
|3.69 MB||Adobe PDF|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.