FUNGICIDAL ACTIVITY OF 3 PUTRESCINE ANALOGS

The synthetic putrescine analogues (E)-N,N,N',N'-tetraethyl-1,4-diaminobut-2-ene(E-TED), the (Z)-isomer (Z-TED) and (E)-N,N-dimethyl-1,4-diaminobut-2-ene(E-DMD) were prepared as their salts, and controlled five important crop pathogens (Erysiphe graminis DC f.sp. hordei Marchal, Uromyces viciae-fabae (Pers.) Schroet, Botrytisfabae Sardina, Podosphaera leucotricha (Ell. & Ev.) Salm. and Phytophthora infestans (Mont.) De Bary). E-TED was also effective in vitro, with growth of P. infestans and Pyrenophora avenae Ito & Kuribay completely inhibited at 1800 and 360 mg litre-1 respectively. When P. avenae was grown in the presence of 180 mg E-TED litre-1 there were significant reductions in putrescine and spermidine concentrations (58% and 35% respectively). An apparent increase in ornithine decarboxylase activity and a decrease in S-adenosylmethionine decarboxylase activity in P. avenae exposed to E-TED at 36 mg litre-1 were not statistically significant. Diamine oxidase activity remained unchanged in fungal tissue exposed to E-TED.