二氧化氯溶液對軟腐細菌Pectobacterium chrysanthemi之殺菌效率及防治文心蘭花梗軟腐病之效果

Bactericidal Efficacy of Chlorine Dioxide against Pectobacterium chrysanthemi and Its Control for Bacterial Soft Rot on Stalk of Oncidium Cut Flower

10.6649/PPB.201006_19(2).0002

趙永椿(Y. C. Chao)；徐世典(S. T. Hsu)；曾國欽(K. C. Tzeng)

二氧化氯 ； 軟腐病菌 ； 軟腐病 ； 防治 ； 文心蘭 ； chloride dioxide ； Pectobacterium chrysanthemi ； soft rot ； control ； Oncidium cut flower

植物病理學會刊

19卷2期（2010 / 06 / 01）

127 - 136

繁體中文

本研究在探討不同濃度之二氧化氯(chlorine dioxide、ClO2)溶液對文心蘭花梗軟腐病菌(Pectobacterium chrysanthemi)之殺菌效率及其應用於切花處理對花梗軟腐病之發生及切花壽命之影響。以ClO2溶液5ppm處理軟腐病菌5分鐘，可完全抑制所有供試菌株之生長。文心蘭花梗以ClO2溶液浸漬處理之濃度在50ppm或以上時，會造成花梗基部産生褐化之藥害現象，但在較低濃度（1、5及10ppm）時，則無明顯藥害。文心蘭切花浸漬於不同濃度(10^2-10^8 CFU ml^(-1))之軟腐病菌懸浮液後，花梗軟腐病之發生程度隨病菌濃度增加而增加，而在此病菌懸浮液中加入最終濃度爲5ppm之ClO2後，軟腐病之發生程度均顯著降低。若ClO2之濃度達10ppm，則完全防止軟腐病之發生。文心蘭切花花梗以5或10ppm ClO2溶液浸漬處理7天後，與只接種軟腐病菌者比較，可顯著減少花朵枯萎或落花數，但與單獨浸漬無菌水相比，則無顯著性差異。此結果表示浸漬處理10ppm ClO2溶液，可防治切花花梗軟腐病，且不會影響切花之壽命。以10ppm ClO2溶液每週一次連續噴灑處理文心蘭植株15週後，不會影響其葉片之生長，且連續噴灑處理40週後，亦不會影響其抽梗數。

The efficacy of chloride dioxide (ClO2) solution in inhibition of growth of Pectobacterium chrysanthemi (Pch), the causal agent of soft rot of Oncidium was evaluated, and its application on Oncidium cut flowers for control of bacterial stalk rot and its effect on longevity of the cut flowers were also studied. Treatment of strains Pch with 5 ppm ClO2 solution for 5 min completely inhibited the growth of all strains tested on an agar medium. Oncidium cut flower stalks showed sign of toxicity (brown discoloration at basal part) after dipped into 50 ppm or above of ClO2 solution for 5 days, but lower concentrations (1, 5 and 10 ppm) were no toxic to the cut flower stalks. Stalks of Oncidium cut flowers were inoculated by dipped into different concentrations (10^2-10^8 CFU ml^(-1)) of Pch. The severity of stalk rot increased with increasing concentrations, but when the inoculums was added with 5 ppm ClO2 solution, the disease severity was reduced significantly at all inoculum level, and the disease was completely controlled with ClO2 added at 10 ppm. Treatment of cut flower stalks by dipping into Pch suspension containing 5 or 10 ppm ClO2 for 7 days reduced significantly the number of withered and fallen flowers as compared with the stalks treated with Pch only, but was not significantly different from those that treated with sterile water. These indicate that dipping treatment with 10 ppm ClO2 solution could control the bacterial stalk rot and did not affect the longevity of cut flower. Spraying leaves of Oncidium plants with 10 ppm ClO2 solution at weekly intervals after 15 weeks did not affect the growth of the leaves, and also did not affect the number of stalks developed after spraying for 40 weeks.