溫度、光照及水分潛勢對高粱麥角病菌即Sphacelia sorghi孢子發芽、菌絲生長及產孢作用之影響

Effect of Temperature, Light Illumination, and Water Potential on Spore Germination, Mycelial Growth, and Sporulation of Sorghum Ergot Fungus Sphacelia Sorghi

陳俊位(C. W. Chen) ； 曾德賜(D. D. S. Tzeng) ； 林俊義(C. Y. Lin) ； 葉瑩(Y. Yeh) ； 楊佐琦(T. C. Yang)

《植物病理學會刊》 4卷3期 (1995/09) Pp. 121-128

https://doi.org/10.6649/PPB.199509_4(3).0004

摘要

以由田間罹病高粱上分離得到之麥角菌(Sphacelia sorghi)菌絲型CST-1菌株及其產孢良好之產孢型CSM-1菌株為供試菌，測試溫度、光照及水分潛勢等對其孢子發芽、菌絲生長及產孢作用之影響，由試驗結果發現，高粱麥角菌之孢子發芽及菌絲生長適溫皆在24-28 C之內。菌絲生長及孢子發芽，均以-10 bar左右水分潛勢狀態最好，在-60 bar以下則孢子發芽與菌絲生長均被抑制。光照(3500 lux白色冷光)處理對麥角菌菌絲生長有略微的促進作用，孢子發芽則有明顯的抑制作用。培養於PDA上之高粱麥角菌在黑暗下有利於其分生孢子之形成，唯主要形成小孢子，而於光照存在下，小孢子分化明顯受抑，總產孢量明顯降低，且所產生者主要為大孢子。本研究中所見溫度、光線及水分潛勢對供試麥角病菌發芽、生長及產孢作用之影響，與過去之調查本病發生所見雨後病害轉趨嚴重之現象極為吻合，有關試驗結果對本病之防治管理應為極有用之資訊。

關鍵字

孢子發芽 ； 環境因子 ； 菌絲生長 ； 高粱 ； 高粱麥角菌 ； 產孢

並列摘要

A wild mycelial strain (CST-1) of Sphacelia sorghi (McRae), isolated from an ergot-infected sorghum and it's conidial mutant (CSM-1) were used to explore the effect of temperature, light illumination and water potential on the germination, mycelial growth and conidiation of sorghum ergot fungus. For both conidial germination and mycelial growth, the optimum temperature was found ranged from 24 to 28 C and the optimum water potential was around -10 bars. The spore germination and mycelial growth were both hardly detectable at temperature beyond the low limit at 12 C or high limit 36 C, and at water potential beyond the low limit at -60 bars. A 12-hour diurnal illumination provided by a pair of cool fluorescent tubes at 3500 lux, was found to be slightly inhibitory to the conidial germination, while was of slightly stimulatory to the mycelial growth. On potato dextrose agar medium, a continuous darkness was a much better condition for conidiation as compared to that in the diurnally illuminated condition. Microconidia appeared to be the predominant fungal propagules produced in the darkness. Whereas in an illuminated condition, the total number of conidiation was greatly reduced; and the predominant fungal propagules produced became the macroconidia. The observed environmental effect on conidia germination, mycelial extention and sporulation were all in accordance to the previous field observation as regard to the correlation of pathogen activities and the seasonal fluctuation of disease incidence. the presented data provided scientific basis useful in strategy formulation for the integrated management of sorghum ergot disease in Taiwan.

並列關鍵字

Conidial germination ； environmental effects ； mycelial growth ； sorghum ； Sphacelia sorghi ； sporulation