A Simple and Economical Method to Induce Sporulation of Pyricularia oryzae

簡易經濟的稻熱病菌（Pyricularia oryzae）產孢誘導方法

陳繹年(Yi-Nian Chen) ； 吳東鴻(Dong-Hong Wu) ； 陳美君(Mei-Chun Chen) ； 陳珮臻(Pei-Chen Chen)

《台灣農業研究》 70卷1期 (2021/03) Pp. 1-10

https://doi.org/10.6156/JTAR.202103_70(1).0001

摘要

It requires a large number of conidia not only for pathogenic races identification of Pyricularia oryzae (the causal agent of rice blast) but also for disease resistance assessment of rice varieties against the pathogen. For stable test result, the same age of conidiospores are also essential for these pathogenicity tests. A mycelial homogenate method (called ＂liquid spawn method＂) modified from the IRRI (International Rice Research Institute) protocol was used to induce simultaneous conidia production of rice blast fungus. The processes are: (1) 4-d-old colony of P. oryzae isolate was cut into numerous pieces and cultured in prune broth for 4 d; (2) homogenizing the whole broth, dispersing the liquid spawn evenly on oat flour agar (OFA) medium plate, air-drying the excess water on the plate, and then culturing the medium at room temperature with natural light illumination for 4 d for conidia production. By use of this method, the conidia yield of several tested isolates of P. oryzae were much higher (2-31 folds) than those with IRRI protocol. In another test, 14 P. oryzae isolates which had very poor conidia yields with regular methods produced significantly higher number of conidia by the method. The results showed that the liquid spawn method could be used for simultaneous and massive sporulation of P. oryzae.

關鍵字

Pyricularia oryzae ； Sporulation ； Conidia ； Liquid spawn ； Oat flour agar

並列摘要

稻熱病菌（Pyricularia oryzae）的生理小種鑑定與水稻品種的抗性評估，都需要大量病原孢子作為接種源進行接種檢定。為獲得穩定的檢定結果，接種源分生孢子的齡期必須具一致性。本研究改良國際稻米研究所常用的稻熱病菌產孢誘導程序〔IRRI（International Rice Research Institute）protocol〕，利用菌絲體均質方式（稱「液態菌種法」）來誘導稻熱病菌在短時間內同時大量產孢。操作程序為：（1）將4日齡的稻熱病菌落以滅菌解剖刀切細碎後，移入加州梅養液中震盪培養4 d；（2）以滅菌均質瓶將菌絲體與養液一起均質作為液態菌種，取適量液態菌種接種於燕麥粉平板培養基（oat flour agar; OFA）上，於無菌操作台中風乾培養基表面多餘水分後，置於室溫、窗邊自然光環境下培養4 d進行產孢誘導。供試菌株採用液態菌種法後的分生孢子產量，明顯高於採用IRRI protocol的孢子產量（2－31倍）。另外，14株於傳統菌絲塊培養法下產孢不良的稻熱病菌株，在採用液態菌種法培養後，所有菌株的產孢量都有顯著提昇。本研究結果顯示，液態菌種法可用於誘導稻熱病菌同時大量產孢。

並列關鍵字

稻熱病 ； 產孢 ； 分生孢子 ； 液態菌種 ； 燕麥粉培養基