瓜類露菌病室內接種試驗

Inoculation of Downy Mildew on Cucurbits under Laboratory Conditions

蔡武雄(W. H. Tsai)

《中華農業研究》 36卷3期 (1987/09) Pp. 311-316

https://doi.org/10.29951/JARC.198709.0009

摘要

於試驗室內利用瓜類之摘葉培養瓜類露菌病菌(Pseudopenospora cubensis)，由於摘葉之葉柄可以生出鬚根，吸收水分，延長摘葉之保鮮時間，使病原菌保存在摘葉一個月以上。一般在胡瓜摘葉後7-9天，洋香瓜7-13天即可生出鬚根。瓜類露菌病菌在15℃，20℃及25℃接種於瓜類葉片4-5天後即可產生病斑，而5-6天後即可產胞。瓜類葉片正背兩面在產生病斑及產胞上無差異。病原菌孢子囊發芽以10℃及15℃最適，在6小時後發芽率達95.18%及97.52%，高溫時發芽率降低。胞子囊釋放游走子之數目以7個最多，3個及11個者最少，平均爲6.7固。室內瓜類露菌病之接種步驟可參考本文圖2方法行之。

並列摘要

Inoculation of downy mildew (Pseudoperonospora cubensis) on detached leaves of cucurbits were studied. Due to the root formation on the petioles of the detached leaves to absorb water, the detached leaves prolonged the fresh period in the petri dishes. Hence, the pathogen could be maintained on the detached leaves over one month. In general, root formation on the detached leaves was, observed 7-9 days on cucumis sativus L. and 7-13 days on cucumis melo L. The lesion formed at 4-5 days and sporulation at 5-6 days after seperated inoculation under 15, 20 and 25°C. No difference was observed on lesion formation and sporulation on both upper and lower leaf surfaces Lesion formation and sporulation were observed 4-5 days and 56 days after inoculation, respectively. The optimum temperature for sporangium germination were observed at 10℃ and 15℃ after 6 hours of incubation, the percentage of germination were 95.18 % and 97.52%, respectively. Germination decreased at higher temperature. Most sporangium produced seven zoospores with an average number of 6.7, a few sporangia produced 3 or 11 zoospores. The procedures for inoculation of downy mildew on cucurbits under laboratory conditions are shown on Fig. 2.