香菇段木美髮網菌之發生及其生活史之觀察

Abstract

由本省香菇栽培區之土庫及埔里所採得之粘菌，依其孢子囊、子囊孢子、變形體、變形膜等特性鑑定為Stemonitis splendens Rost。調查本菌孢子囊在香菇栽培場發生情形發現其在4~10 月間發生較多，尤其在7 月達到高峰，出現率為1~14%。若以樹種而言，則硬質木材比軟質木材較不易被感染，且感染率隨著栽培時間而增加，在所有調查的一年半以上段木中以黃槿受感染率為30%為最多。當以七種不同培養液來培養子囊孢子時，發現20%木汁中的發芽率最高，可達85%，而在黑暗下較有利發芽，發芽所需時間為48~72 小時。段木經本菌孢子接種後，若有傷口處理則感染率為86%，在無傷口處理時為4%，而接種後所產生之子實體以光學顯微鏡觀察時發現其特性與原先採得者一致。由田間觀察及室內試驗結果可將本菌作成一生活史圖。本菌在香菇段木上完成其生活史所需時間為120 天，但會受環境因子如溫度、濕度等之影響而改變。Depending on the morphological characteristics of sporangia, sporangiospores and hypothallus, the slime mould collected from the logs of shiitake at Tuku and Puli were identified as Stemonitis splendens Rost.. During the year, more fruiting bodies of the fungus were observed from April to October, with a maximum of occurrence in July, and the infection percentage on logs were between 1% and 14%. The soft-wood logs were more easily attacked than hard-wood logs by the fungus, and the infection percentage increase with the log ages. The highest infection, i. e, about 30%, was observed in the logs of yellow basket willow (Engelhardtia roxburghiana) after 1.5 years or longer of cultivation.