蘭菌配合植物生長物質對拖鞋蘭開花之影響

Abstract

摘要 利用五種絲核菌屬蘭菌（R01、R02、R04、R13、R14）單獨接種在兩個品種的拖鞋蘭小苗上，栽培四個月後調查，在Alma Gavaert 'Goto' x Maudiae 'Silverado' AM/AOS品種中，R02能促進葉片長度及增加鮮重，且接種R02的小苗存活率達100％。另一品種Alma Gavaert 'HB' x Janet Kunkle 'Grace Hsinying接種R13能促進葉片的長度，接種R02、R14能增加植株的鮮重。試驗結果顯示接種R02、R13、R14對拖鞋蘭小苗生長有促進的效果，且能提高小苗的存活率。經由光學顯微鏡的觀察，可以確認所接種的蘭菌屬於絲核菌屬，利用掃瞄式電子顯微鏡術（Scanning electron microscopy；SEM）觀察到菌絲藉由根毛細胞侵入蘭花根部，逐漸向內侵入根被、外皮層、皮層，但並不會感染到中心柱內。菌絲侵入皮層細胞後會開始形成菌絲團，再以單一菌絲侵入鄰近的細胞，逐漸擴張感染區域。共軛焦顯微鏡提供菌絲團的立體影像，從不同的角度觀察菌絲團及感染情形。觀察結果得知，絲核菌感染拖鞋蘭根部的模式為菌球消化型。 植物生長素對拖鞋蘭栽培之影響。拖鞋蘭斑葉原生種Paphiopedilum delenatii接種R02配合太空精的施用可以增加葉數及鮮重，處理四個月後其鮮重（10.7克）比對照組（6.8克）增加約3.9克。拖鞋蘭綠葉原生種Paphiopedilum rothschildianum施用太空精能增加葉綠素讀值及第一、二葉長度；菌種R04配合太空精或氯化膽鹼能增加葉片數目。拖鞋蘭雜交種Impulse '376-1' x fairrieanum 'Bounds'接種蘭菌R02配合品全王的施用對拖鞋蘭的葉數、第二葉片長度及鮮重有顯著的增加；接種蘭菌R02配合太空精，其葉數、第一葉片長、及葉綠素讀值及鮮重與對照組相比，都達到顯著差異。拖鞋蘭雜交種 Alma Gavaert 'Goto' x Maudiae 'Silverado' AM/AOS，單純接種R02而不施用藥劑，或接種R01，R02，配合品全王處理其植株鮮重與對照組相比都有顯著的促進。R02配合太空精則對第二葉片長和葉綠素讀值的增加有顯著效果。 噴施GA3 70 ppm或GA3 70 ppm配合BA 30 ppm在拖鞋蘭植株Paphiopedilum Maudiae type可促使拖鞋蘭花梗抽出，但噴施GA3植株所開出的花朵會出現上萼片及花瓣反捲，花瓣寬度減少，花梗扭曲等現象，失去觀賞價值；若GA3配合BA共同處理Paphiopedilum Maudiae type，一樣會導致畸形花的發生；僅噴施BA 30ppm於Paphiopedilum Maudiae type所開出花朵可自然展開，且花之長寬和對照組相比約多出一公分，顯示BA可導致拖鞋蘭花朵增大。而接種蘭菌並不會改善畸形花的情形。試驗二施用GA3 70 ppm及BA 30 ppm在尚未花芽分化的拖鞋蘭雜交種上，發現並無植株抽梗，因此推論，GA3可誘導8％植株開花，但BA則無，其主要的功能應該為促進花梗快速抽長。降低GA3施用的濃度至10 ppm或30 ppm，所開出來的花朵也為畸形花，因此在拖鞋蘭（Paphiopedilum Maudiae type），BA之施用有利於開花，且提升開花品質，但GA3之施用則不宜。

Abstract After inoculating one of five Rhizoctonia orchid mycorrhizal fungi(OMF) : RO1 R02 R04 R13 R14 with two cultivars of Paphiopedilum seedlings for 4 months ,we investigated the effects of OMF on the growth of were investigated. Resent showed that in Alma Gavaert 'Goto' x Maudiae 'Silverado' AM/AOS, inoculation with R02 increased the leaf length, fresh weight, and the survival rate 100% of seedlings. In another cultivar ,Alma Gavaert 'HB' x Janet Kunkle 'Grace Hsinying, inoculatioin with R13 increased leaf length and inoculation with R02 and R14 increased the fresh weight of seedlings. It showed that inoculatioin with OMF R02、R13、R14 enhanced the growth and survival rate of Paphiopedilum seedlings. The OMFs in this experiment belonged to Rhizoctonia spp.. It was observed that hypha invaded into orchids root mainly throught root hair cell, and then penetrated throught velamen, exodermis, and then cortex region, but would not reach stele。Hypha formed pelotons in cortex cells and infected neighboring cells by single hypha. Confocal microscop could show 3-D image of pelotons. It was concluded that the model of symbiosis between Rhizoctonia and root of Paphiopedilum is tolypophagy. Effect of plant growth substance on Paphiopedilum showed that inoculation of R02 then applied of Aminosong could increase leaf number and fresh weight of Paphiopedilum delenatii. This treatment increased 3.9 g in fresh weight after four months of treatment control. Aminosong treatment could increased CMR and the length of the first and the second leaf of Paphiopedilum delenatii. Inoculation with R04 and then applied Aminosong or choline chloride increased leaf number. In Paphiopedilum hybrida Impulse '376-1' x fairrieanum 'Bounds', inoculation with R02 paired with use of Lysine＃24 significantly increased leaf number, length of the second leaf and fresh weight significantly. Inoculation with R02 paired with Aminosong also significantly increased leaf number, length of the first leaf, CMR, and fresh weight in this cultivar. In another Paphiopedilum hybrida Alma Gavaert 'Goto' x Maudiae 'Silverado' AM/AOS, inoculation with R02 alone or inoculation with R01 or R02 plus the application of Lysine＃24 improved fresh weight substantially them the control. Inoculation with R02 and applied with Aminosong increased length of the second leaf and CMR significantly in this cultivar. Spraying GA3 70 ppm or GA3 70 ppm + BA 30 ppm improved flower stalk emergence on Paphiopedilum Maudiae type, but the flowers with GA3 treatment formed abnormal flower, such as rolled in sepal and petal, reduced in width of petal and twisted in stalk, which lead to loss of ornamental value. GA3 and BA co-treatment also lead to the same result. Only when spraying 30 ppm BA on Paphiopedilum Maudiae type, flowers opened naturally and the length and width of flower were both 1cm longer than the control. This suggested that BA significantly increased flower size of Paphiopedilum Maudiae type. Inoculating with OMF could not reduce flower abnormality as caused by GA3 treatment. Spraying GA3 70 ppm + BA 30 ppm on Paphiopedilum hybrida before the appearance of flower bud would not caused flower stalk emergence at all. GA3 can induce 8% of flower stalk emergence, but BA treatment could not induce flower stalk formation of slipper orchids. Therefore it was concluded that the main function of BA possibly was to induce the flower stalk emergence for those plants already had flower buds. Reducing the GA3 concentration to 30 ppm or 10ppm also produced abnormal flowers. Therefore it was suggested that spraying BA on Paphiopedilum Maudiae type is beneficial to flowering and improving flower quality of slipper orchids. In contrast, GA3 was not recommended.