Effect of Water Potential on Mycelial Growth, Reproduction and Spore Germination by Fusarium moniliforme

Fusarium moniliforme의 Propagule형성(形成)과 발아(發芽)에 미치는 Water Potential의 효과(效果)

Hyphal growth by Fusarium moniliforme was best at -14 bars osmotic water potential. Hyphal growth was prevented at -94 bars. The production of microconidia was best at -14 bars osmotic potential and prevented at -84 bars regardless of Strain. In contrast, this fungus sporulated macroconidia best at -1.4 bars and progressively less with each increment drop in water potential below that of basal media. The rate of spore germination followed a similar pattern with all of the spores; uniformly maximal at about -1.4 bars and progressively slower as the water potential was lowered from -1.4 bars to -42 bars. Under the natural conditions, plants infected by F. moniliforme produce microconidia on the dead tissues instead of producing macroconidia. This phenomenon agrees well with the water potential experiment since the dead plant tissues have a lower water potential than the living plant.

Fusarium moniliforme strain별 균사신장(菌絲伸長)은 Strain IV은 water agar나 PDA에 관계(關係)없이 -14 bars에서 좋았고 -80 bars에서도 균사(菌絲)자람이 정지되지 않았다. Strain II와 Strain IV 를 비교(比較)하여보면 Strain II가 Strain IV보다 각 water potential 에서 균사(菌絲)자람이 좋았다. 분생포자형성(分生胞子形成)은 Strain에 관계(關係)없이 소형분생포자(小型分生胞子)는 0에서 -20bars까지는 점점(漸漸) 형성(形成)이 증가(增加)하다가 -20bars에서 가장 많이 형성(形成)되었으며 -80bars에서도 아주 적은수이지만 형성(形成)이 되었다. 대형분생포자(大型分生胞子)는 -1.4bars에서 포자형성(胞子形成)이 잘 되었고 water potential 떨어짐에 따라 -32bars에서 대형분생포자(大型分生胞子)를 형성(形成)하지 않고 소형분생포자(小型分生胞子)만 형성(形成)하였다. 포자발아(胞子發芽)는 -1.4bars에서 발아율(發芽率)이 좋았고 water potential이 떨어질수록 발아율(發芽率)도 떨어졌다.