抽象的

Pathogenic classification of parasitic diseases in plant.

Ruanpanun Zhang

Infection of plants occurs when spores of the pathogen fall on susceptible host leaves or stems and germinate, each spore producing a germ tube. Tubes grow on the surface of the host until an opening is found. The tube then penetrates the host, spreading branches between the host's cells and forming a hypha within the penetrated tissue. The germ tube of some fungi produces a special compression organ called the aspersorium, from which microscopic needle-like pins compress and pierce the epidermis of the host. After invasion, the mycelium develops in the usual way.