Growth and Physiological Response of Resistant Alfalfa Clones Infected with<i>Verticillium albo-atrum</i>

Abstract

Verticillium albo-atrum previously was reported to reduce the growth and flowering of resistant alfalfa cultivars. However, attempts to determine whether the pathogen directly affected the growth of individual resistant plants were thwarted by the fact that each alfalfa cultivar is a heterogeneous population of plants encompassing all levels of resistance to V. alboatrum. Inoculation of an alfalfa cultivar and the subsequent death of susceptible plants resulted in the emergence of an inoculated-resistant subpopulation―a subpopulation that could not be duplicated in the absence of the pathogen (...)