B. Interactions between Strains of the Same Virus
3. Theory of the Occupied Receivers
To explain the phenomenon described above, Hutton and Bawden (1950) suggest that unrelated viruses increase on receivers or on specific increasing surfaces. When a virus finds these receivers occupied by the first strain inoculated, they are incapable of duplication.
All the theories recognize that interference between strains of a virus is due to competition. Either the first strain launches the attack on host organs, which will not permit a new inoculation, it exhausts the nutrient reserve of the cell, or it quickly occupies a space. In all these suppositions no direct interaction exists from one virus strain to another strain.
IX. G E N E R A L CONSIDERATIONS
This chapter has reviewed the many aspects of biological interfer
ence as it pertains to plant disease and its epidemiology. The many soil organisms grow, compete with one another, act and interact in a highly complex system. Pathogens tend to be restricted in their development through these interactions. The resulting biological equilibria result sometimes in complex diseases and sometimes in the suppression of pathogens. The use of biological control measures to curb plant diseases has some promise, and exploitation of this idea may some day be more effectively used in curbing plant pathogens.
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