The impact of parasitism on resource allocation in a fungal host: the case of and its mycovirus, Cryphonectria Hypovirus 1.

Parasites are known to profoundly affect resource allocation in their host. In order to investigate the effects of Cryphonectria Hypovirus 1 (CHV1) on the life-history traits of its fungal host an infection matrix was completed with the cross-infection of six fungal isolates by six different viruses. Mycelial growth, asexual sporulation, and spore size were measured in the 36 combinations, for which horizontal and vertical transmission of the viruses was also assessed.

Multiple introductions and recombination in Cryphonectria hypovirus 1: perspective for a sustainable biological control of chestnut blight.

Cryphonectria hypovirus 1 (CHV1) is a mycovirus which decreases the virulence of its fungal host Cryphonectria parasitica, the causal agent of chestnut blight recently introduced in Europe. The understanding of the evolutionary processes which have shaped CHV1 populations in Europe is required to develop a sustainable biocontrol strategy targeting chestnut blight and effective in European chestnut forests. To retrace the evolutionary history of CHV1, we analyzed sequences from two genomic regions on a collection of 55 CHV1 strains from France and northern Spain, two countries where multiple introductions of C.

Sigma virus and male reproductive success in .

The risk of disease transmission can affect female mating rate, and thus sexual conflict. Furthermore, the interests of a sexually transmitted organism may align or diverge with those of either sex, potentially making the disease agent a third participant in the sexual arms race. In , where sexual conflict over female mating rate is well established, we investigated how a common, non-lethal virus (sigma virus) might affect this conflict.

Mycovirus transmission revisited by in situ pairings of vegetatively incompatible isolates of Cryphonectria parasitica.

In disease ecology, parasite transmission is a key parameter important at both epidemiological and evolutionary scales. Mycoviruses can be transmitted both horizontally and vertically. Their horizontal transmission is strongly restricted by the host vegetative compatibility system, which controls the outcome of somatic fusion in fungi, and by the same way, may limit mycovirus transmission.

Parasitism and maintenance of diversity in a fungal vegetative incompatibility system: the role of selection by deleterious cytoplasmic elements.

In fungi, horizontal transmission of deleterious cytoplasmic elements is reduced by the vegetative incompatibility system. This self/non-self recognition system may select for greater diversity of fungal incompatibility phenotypes in a frequency-dependent manner but the link between the diversity of fungal phenotypes and the virulence of cytoplasmic parasites has been poorly studied. We used an epidemiological model to show that even when transmission between incompatibility types is permitted, parasite pressure can lead to high levels of polymorphism for vegetative incompatibility systems.