台灣三種木本植物之輪斑病

Zonate Leaf Spot on Three Woody Plants in Taiwan

張東柱(Tun-Tschu Chang)

《林業試驗所研究報告季刊》 10卷2期 (1995/06) Pp. 235-240

https://doi.org/10.7075/BTFRI.199506.0235

摘要

輪斑病發生於水黃皮、苦棟與構樹等三種木本植物的葉片。罹病植物的葉片初為褐色圓形的小斑點上呈輪紋狀，小輪斑可繼續擴大或互相癒合成大形輪紋斑，最後導致整葉枯萎掉落。病組織可見病原菌的孢子束(sporophores)，小孢子(microconidia)與菌核(scleraotia)等構造分離與鑑定後，證實本病為輪斑病菌(Cristulariella moricola Redhead)所引起。將病組織之孢子束與病原茵純培養所形成的菌核接分別種至上述三種寄主植物的葉片後，兩者均可產生與自然感染的病徵相似。其中以孢子束充當接種源的感染率較以菌核接種者為高。本病菌在PDA培養基與15~20℃的條件下產生成熟的菌核。本菌菌絲最適應生長溫度介於15~25℃之間，以20℃為最佳。溫度高於30℃時，本菌的生長完全受抑制。本菌之菌核埋於20%和40%含水量的土壤中，六個月內即完全不能發芽；至於埋在0%和10%含水量的土壤者，直到第12個月才失去發芽能力。

關鍵字

水黃皮 ； 苦楝 ； 構樹 ； 輪斑病 ； Cristulariella moricola

並列摘要

Zonate leaf spot caused by Cristulariella moricola Redhead was usually observed on Pongamia pinnata (Linn,) Merr., Melia ozedarach Linn, and Broussonetia papyrifera Sieb. At beginning, several small zonate brown lesions occurred on leaves. Those small lesions became larger zonate leaf spots after developing or growing together, and eventually caused the leaf blighted and defoliated. The disease symptom was reproduced by inoculation of host leaves with sporophores obtained from disease tissues or sclerotia from pure culture of C. moricola. The fungus was also reisolated from the inoculated leaves to complete the pathogenicity tests. Use of sporophores for inoculation caused more severe disease than use of sclerotia. Sclerotia were in vitro produced on PDA medium between 15 and 20℃. Optimum temperature range for fungal growth was 15-25℃ and 20℃ was the most optimal. Temperatures above30℃ completely inhibited the fungal growth. Sclerotia of the fungus lost their germination ability within 6 months after they were boned in tail with 20% and 40% (w/w) water content (wc). However, sclerotia in tail with 0 and 10% (w/w) wc did not lose their germination ability until the 12th month after treatment.

並列關鍵字

Pongamia pinnata ； Melia azedarach ； Broussonetia papyrifera ； Zonate leaf spot ； Cristulariella moricola