Effect of calcium and calmodulin modulators on the development of Erysiphepisi on pea leaves

The effect of calcium and calmodulin modulators, viz., ethylene glycol bis (beta -amino ethyl ether)-N,N,N',N'-tetraacetic acid (EGTA), a calcium chel ator; verapamil, a plasma membrane Ca2+ channel blocker: ruthenium red, an organelle Ca2+ channel blocker; and chlorpromazine, a calmodulin antagonist ; on the development of Erysiphe pisi was studied by floating the inoculate d leaves on the respective solutions of chemicals. All the modulators affec ted the development of E. pisi by inhibiting the colony diameter, number of secondary branches, number of hyphal cells per colony and number of hausto ria. The calmodulin antagonist was more effective in reducing E. pisi devel opment. The results suggest the possible involvement of calcium and calmodu lin in the development of E. pisi on pea leaves.