Role of polyphenol oxidase, peroxidase and total phenol content in differential resistance of Dioscorea species to Fusarium moniliforme

Abstract

An experiment was conducted to find out the possible relationship between phenolic contents and peroxidase
activities of different Dioscorea spp to Fusarium moniliforme Sheldon. Dioscorea cayenensis Lam and D. dumelorum
(Knuth) Pax had very high content of polyphenol oxidase. peroxidase and total phenol was resistant to F moniliforme.
D. rolundata Pair, D. alata L. and D. esculenta (Lour) Burk had low contents of polyphenol oxidase, peroxidase and
total phenol contents and were susceptible to F moniliforme. Phenolic contents and peroxidase activities decreased with
increase in the age of yam tubers with the increase in rate of of infection. There was a sharp rise in the amount of
phenolic compounds and peroxidase activities at the start of the infection. They later dropped as the infection progressed.