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The Influence of Seedling Exudates on the Resistance of Peas to Fusarium and Pythium Root Rot. J. M. Kraft, Research Plant Pathologist, A.R.S., U.S.D.A., Western Region, Irrigated Agriculture Research and Extension Center, Prosser, Washington 99350; Phytopathology 64:190-193. Accepted for publication 6 August 1973. DOI: 10.1094/Phyto-64-190.

Peas with pigmented seeds, both resistant and susceptible to root rot, produced like amounts of phenols and reducing sugars in exudates from germinating seeds and seedlings. However, only exudates from resistant lines (P.I. Nos. 140165 and 257593) inhibited sporulation of Fusarium solani f. sp. pisi, growth of Pythium ultimum in vitro, and conidial germination of F. solani in soil. Lesions, caused by F. solani, on epicotyls of 4- and 6-day-old resistant plants were fewer and coalesced less rapidly than on epicotyls of susceptible plants. Factors, other than phenols and reducing sugars in seed and seedling exudates may also play a role in the resistance of peas to F. solani and P. ultimum.