RESISTANCE AND SUSCEPTIBILITY OF SELECTED ALFALFA LINES TO INOCULATION WITH A PHYTOPHTHORA MEGASPERMA ISOLATE

Abstract

Alfalfa seedlings were grown in soil collected from a field depicting "alfalfa sickness." A vigorous line (resistant) and a less vigorous line (susceptible) were selected for study. Both lines were grown in sterilized sand subjected to three treatments: control; inoculated with the fungal isolate; inoculated with a soil suspension from alfalfa "sick" soil. Both inocula severely stunted growth and produced severe root lesions on the susceptible line but had no effect on the resistant line, indicating good resistance to the disease.