What allows wheat mosaic virus to survive and build up in the early season?

The ability of wheat mosaic virus to survive and build up in the early season is largely due to volunteer wheat. Volunteer wheat refers to wheat plants that grow from seeds left in the soil from the previous harvest. These plants can serve as a reservoir for the virus, allowing it to perpetuate itself from one growing season to the next. In early spring, when conditions are favorable for growth, these volunteer plants can become infected and facilitate the spread of the virus to newly planted wheat crops. This cycle can lead to increased disease incidence in subsequent wheat generations.

In contrast, while infected soil, high humidity, and fungal infections may contribute to plant disease dynamics, they do not play the same crucial role in the early survival and buildup of wheat mosaic virus specifically. Infected soil might harbor pathogens, but it is the presence of live host plants like volunteer wheat that directly supports the virus's life cycle. High humidity may create optimal conditions for certain pathogens but does not directly enable the virus's survival through the early season in the same way as volunteer wheat. Fungal infections can affect wheat health but are separate from the specific mechanisms through which wheat mosaic virus persists and spreads.