Do collembola affect the competitive relationship among soil-borne plant pathogenic fungi?

The feeding preference of the collembolan Protaphorura armata in the presence of Fusarium culmorum (Fc) and Gaeumannomyces graminis tritici (Ggt), two soil borne fungi pathogenic for winter cereals, were studied in a simplified system including wheat seedlings. Analysis of gut content of animals from microcosms containing both fungi, showed that Fc was clearly preferred, but that Ggt was also fed. At microscopic examination, the majority of Fc conidia present in the gut lacked cytoplasmic content and only cells were intact. The feeding preference of P. armata favoured Ggt over Fc in the competition for infection sites on wheat seedlings. The viability of fungal propagules after passage to the gut was also studied. No colonies of Ggt and only few colonies of Fc developed from faecal pellets set on agar medium.