水稻紋枯病菌單擔胞子菌株間之培養性狀、抗藥性和病徵型之比較

Culture Characteristics, Chemical Tolerance and Symptom Types of Single-Basidiospore Isolates of Thanatephorus Cucumeris

杜金池(C. C. Tu) ； 張贛發(K. F. Chang)

《中華農業研究》 25卷1期 (1976/03) Pp. 13-22

https://doi.org/10.29951/JARC.197603.0003

摘要

本研究以自然環境下發生於黃麻田間成熟黃麻株接近地面莖部之Thanatephorus cucumeris子實層所分離之17個單擔胞子菌株和母菌株（分離自次子實層菌絲單細胞）爲材料。各單擔胞子菌株之培養性狀，包括菌絲生長速度、培養基酸鹼度之變化、菌落色澤和菌核產生情形等，不但和母菌株不盡相同，而且菌株間亦互不一致。少數菌株對五氯硝苯(PCNB)之抗性和母菌株相似，但大部份菌株之抗藥性均有增強之趨勢。
供試各菌株對黃麻幼苗均有病原性，罹病幼苗於近地面莖部初呈水浸狀斑點，繼之呈黑褐色不規則形斑塊，略凹陷，俟病斑擴大環繞全莖後表皮裂開，纖維裸露，並自病患處腰折枯死。各菌株對水稻亦有不同程度之病原性，但病徵型却可分成三種：7個菌株和母菌株之病徵型相同，產生典型紋枯病雲狀病斑；另4個菌株產生較小型類似紋枯病之斑駁，惟病斑中央爲灰褐色；其餘6個菌株產生褐色條狀斑，並具淡黃色暈圈。

並列摘要

Seventeen single-basidiospore isolates were isolated from the hymenial layer of Thanatephorus cucumeris produced on the mature jute stem in the field. These isolates showed great variations on hyphal growth rate, PH value changes of culture medium, colony color, and sclerotial formation. The parent clone showed a moderate tolerance to penta-chloronitrobenzen (PCNB) with 42-66% of growth inhibition at the concentrations of 100-4,000 ppm. However, 2 single-basidiospore isolates showed the same degree of PCNB tolerance as the parent clone, 4 isolates lower, and the rest 11 isolates higher than the parent.
All single-basidiospore isolates as well as the parent clone were pathogenic to jute seedlings showing typical symptoms of seedling damping-off. These isolates were also pathogenic to rice plants but with variable symptoms. The symptoms on rice plants could be grouped into 3 types: seven isolates and the parent clone showed the typical sheath blight spot, 4 isolates produced sheah blight-like spot with grayish-brown color in the central part, and the rest 6 isolates produced rod-like brown spot with yellowish-brown margin. Since the variations are too great among single-basidiospore isolates, it is, therefore, concluded that neither culture characteristic nor symptom type can be served to distinguish strains of T. cucumeris.