Resistance and susceptibility to tobacco mosaic virus (TMV) in the tomato, Lycopersicon esculentum, demonstrated by histological differences in the development of stem tissue

Abstract

Seedlings of two tomato varieties, one susceptible and the other resistant to TMV, were inoculated at the first true leaf stage with a mixed inoculum of TMV and PVX. PVX was added to induce an active and uniform reaction. The seedlings were then grown in flats in the greenhouse, and plants were harvested each day following the initial inoculation for a period of eighteen days. The stems of these plants were fixed, embedded in paraffin, sectioned and stained. Examination of the different cross sections revealed distortions in the development of the vascular system of the susceptible variety.