|Title:||麻竹銹病流行學之研究||Other Titles:||The Epidemiology of Ma Bamboo Rust||Authors:||蔡阿輝
|Issue Date:||9-Sep-1985||Publisher:||農業試驗所||Journal Volume:||34||Journal Issue:||3||Start page/Pages:||323-328||Source:||中華農業研究||Abstract:||
本試驗之目的在建立麻竹銹病流行學之華本資料包括一年內之消長，病菌夏胞子發芽最適之溫度與所需的時間及存活與潛伏期，藉以了解病害發生之生態做研擬防治對策之參考。從72 年1 月到12 月每月中旬前往雲林縣古坑鄉一選定竹園調查麻竹鐫病之消長情形，結果發現一年之中均有銹病發生；若以枝條區分，靠近基部之葉片銹病最多，往上遞減；若以月份區分，則以五、六月最少，七月逐漸上升，到十月左右即達病害發生之高峰，一月枝條基部葉片開始脫落，病害逐漸減少，從一月至十二月平均葉片受害面積率為12.8 、8.4 、5.3 、1.9 、0.2 、0.6 、3.0 、10.3 、15.8 、30.4 、33.9 及35.8 %。病菌之夏胞子在16-28℃ 之問發芽均良好，但以20℃ 左右最佳，夏胞子在游離水中配合適當之溫度2 小時內即可發芽而且具有發芽能力者大約在12 小時內全部發芽。在麻竹葉片上從接種夏胞子到產生夏胞子堆的時間約10-12 天。夏胞子在室溫下存活大約三星期即失去發芽力，但若在病葉上大約可維持一個月，若將夏胞子或病葉保存在4 ℃ ，經過二個月尚有50 %之夏胞子可以發芽，因此掉落在竹園之乾葉片上的夏胞子不會存活太久，在落葉上也未發現有冬胞子，故可能不是翌年初次感染源（primary inoculum）之主要來源，而停留在新鮮葉片上之夏胞子堆，等到次年環境條件適合時即開始產胞，才是重要之感染源，同時也是發病季節裡，造成重複感染之來源，因此清除落葉可能對病害之防治沒有太大的幫助。
Due to the intensive and extensive culture of ma bamboo (Dendrocalamus latiflorus Munro) in the recent decades, rust of ma bamboo has become a disease of economic importance in Taiwan. Informations of this disease in the literatures were mycological studies such as host range, identification and morphological description of the causal organism without any pathological or epidemiological research. We report the incidence of ma bamboo rust in a year, the effect of temperature and time on the germination, the survival and the growth of germ tube of uredospores, and the incubation period of ma bamboo rust on the detached leaves. Observations were made in a ma bamboo field at Kukeng, Yuinlin County where ma bamboo is a major crop. Five labeled branchlets each of the ten randomly selected bushes were observed leaf by leaf once a month in the middle of every month in 1983. A standard key of cereal rust was used to assess, by naked eyes, the percentage of ma bamboo leaves covered with rust lesions. Mean percentage of the 50 branchlets were recorded with 12.8, 8.4, 5.3, 1.9, 0.2, 0.6, 3.0, 10. 3, 15.8, 30.4, 33.9, and 35.8% of rust lesions from January through December, respectively, and the severity of the leaves on a branchlet decreased gradually from stem-end to the tip-end. Fresh uredospores from infected leaves were used to prepare suspension (ca. 2 ×104 spores/ml) for inoculation and germination tests. Germinations were conducted on 1.5% water agar plates at various temperature regimes and times. The optimal temperatures for germination and growth of germ tube were observed between 16 and 23°C with a maximum at 20°C. Uredospores germinated within 2 hours at 20°C and reached to the highest percentage of germination in about 12 hours. The incubation period of the disease on the detached leaves were recorded 10 to 12 days in petri plates at room temperatures (18-28°C). Uredospores lost their viability drastically at room temperatures. However, if they were stored at 4°C, about 50% of the uredospores were still able to germinate after 8 to 10 weeks. Therefore, we consider the uredospores in the diseased leaves falling on the ground are not important source of inoculum for the epidemics of the following year. Collecting and burning of the diseased leaves on the ground may give little help for the control of ma bamboo rust in the field. No teliospore formation was observed during the course of this study.
|Appears in Collections:||1.台灣農業研究(1950～迄今)|
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