Abstract
Reactions of alfalfa protoplasts of sic genotypes (three resistant ant three susceptible genotypes) to Verticillium albo-atrum culture filtrates fractionized by different molecular cut-off (3,500, 12-14,000 and 50,000) and to the cell wall components were investigated. Protoplasts derived from susceptible genotypes reacted to a low molecular weight fraction (3,500 <) more highly than those derived from resistant genotypes. On the other hand, protoplasts derived from resistant genotypes reacted to high molecular weight fractions 12-14,000 〜 50,000, > 50,000) and V. albo-atrum cell wall components more highly than those from susceptible genotypes. These results indicate that low molecular weight fractions may be useful for in vitro selection using V. albo-atrum culture filtrate, and that the percentage of reacted protoplasts to the fungal cell wall components may be a good indicator for the in vitro resistance.
