腐霉菌是花卉根腐病的主要病原之一,它存在于未经杀菌处理过的土壤中,也可能存在于冲洗过的细沙及某些草炭介质中。腐霉菌与水有着密切的关系,因为他们产生的游动孢子要通过水进行散播或游动。尽管这些病原菌和土壤中其他病原菌相比不算是很强的竞争者,但是它们可以通过球形、厚壁的休眠孢子(卵孢子)在土壤中存活多年。这些卵孢子也通常存在于患病组织中, Pythium is one of the major pathogens of flower root rot. It exists in the soil without sterilization and may also exist in washed sand and some peat media. Pythium and water are closely related, because they produce zoospores to spread through the water or swimming. Although these pathogens are not very strong competitors compared to other pathogens in the soil, they can survive in the soil for many years through spherical, thick-walled resting spores (oospores). These oospores are also commonly found in diseased tissue,