Statistical Aspect of the Production of Primary Lesions by Plant Viruses

Abstract

AN analogy has frequently been drawn between the production of bacterial colonies on artificial media and of primary lesions on the leaves of susceptible host plants inoculated with an extract of virus-diseased tissues. In a recent paper, Youden, Beale and Guthrie¹ have carried this analogy one step further, and have suggested that the relation between the numbers of lesions and the relative concentrations of virus particles in the inoculum may be described in the same way as the relation between the numbers of bacterial colonies and the concentration of bacteria in the plated suspension. Their equation takes the form: where y is the number of lesions given at any concentration x of the virus, N represents the maximum lesions obtainable, and a is a constant.